commit a739007e23ada64038d59557e18bb5cbe8709d71 Author: Dale Mellor Date: Mon Mar 23 15:33:18 2020 +0000 Genesis. diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..4673a3a --- /dev/null +++ b/.gitignore @@ -0,0 +1,33 @@ +*.o +*.lo +.deps +.libs +stamp-h1 +*.la +*~ +autom4te.cache +aclocal.m4 +config.guess +config.log +config.status +config.sub +configure +auto-config.h +auto-config.h.in +depcomp +dmbcs-micro-server.html +dmbcs-micro-server.pc +install-sh +libtool +ltmain.sh +m4 +makefile +makefile.in +missing +micro-server.pc +micro-server.info +texinfo.tex +mdate-sh +stamp-vti +version.texi +compile diff --git a/AUTHORS b/AUTHORS new file mode 100644 index 0000000..e69de29 diff --git a/COPYING b/COPYING new file mode 100644 index 0000000..94a9ed0 --- /dev/null +++ b/COPYING @@ -0,0 +1,674 @@ + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. diff --git a/ChangeLog b/ChangeLog new file mode 100644 index 0000000..e69de29 diff --git a/DMBCS/micro-server/http-server--impl.h b/DMBCS/micro-server/http-server--impl.h new file mode 100644 index 0000000..2cd8af6 --- /dev/null +++ b/DMBCS/micro-server/http-server--impl.h @@ -0,0 +1,106 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__HTTP_SERVER__H +#error The http-server--impl.h header should not be included in application code. +#endif + + +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + /* This is the detailed implementation of the \c return_* methods + * below, which form the public interface to be used by + * applications. */ + void return_payload (const int client_socket, + const string_view http_type, + const string_view origin_url, + const char *const payload, + const size_t length); + + + + inline void Http_Server::return_html (int const socket, string const &html) + { + return_payload (socket, "text/html", {}, html.c_str (), html.length ()); + } + + + + inline void Http_Server::return_text (int const socket, string const &text) + { + return_payload (socket, "text/plain", {}, text.c_str (), text.length ()); + } + + + + inline void Http_Server::return_css (int const socket, string const &text) + { + return_payload (socket, "text/css", {}, text.c_str (), text.length ()); + } + + + + inline void Http_Server::return_pdf (int const socket, string const &pdf) + { + return_payload (socket, "application/pdf", {}, pdf.c_str (), pdf.length ()); + } + + + + inline void Http_Server::return_json (int const socket, + string const &json, + const string_view origin_url) + { + return_payload (socket, "application/json", origin_url, + json.c_str (), json.length ()); + } + + + + inline void Http_Server::return_bad (int const socket) + { return_payload (socket, "text/plain", {}, nullptr, 0); } + + + + inline void Http_Server::return_png (int const socket, + vector const &png) + { + return_payload (socket, "image/png", {}, + (char const *) png.data (), png.size ()); + } + + + inline void Http_Server::return_svg (int const socket, string const &svg) + { + return_payload (socket, "image/svg+xml", {}, svg.c_str (), svg.length ()); + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/http-server.cc b/DMBCS/micro-server/http-server.cc new file mode 100644 index 0000000..fd97b4d --- /dev/null +++ b/DMBCS/micro-server/http-server.cc @@ -0,0 +1,184 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include + + +namespace DMBCS { namespace Micro_Server { + + + + string Http_Server::add_html_headers (string const &&body) + { + auto hold = ostringstream {}; + + hold << "Content-type: text/html; charset=utf-8\r\n" + << "Content-length: " << body.length () << "\r\n\r\n"; + + return hold.str () + move (body); + } + + + + void return_payload (const int socket, + const string_view type, + const string_view origin_url, + const char *const payload, + const size_t length) + { + ostringstream out {}; + + out << "HTTP/1.1 200 OK\r\n"; + + if (origin_url.size ()) + out << "Access-Control-Allow-Origin: " << origin_url << "\r\n"; + + out << "Content-type: " << type << "; charset=utf-8\r\n" + << "Content-length: " << length + << "\r\n\r\n" + << string {payload, length}; + + write (socket, out.str ().c_str (), out.str ().length ()); + } + + + + static string extract_header (const vector& request, + const string& tag) + { + static const regex re {"[\r\n]" + tag + ":[[:space:]]*([^\r\n]*)"}; + match_results::const_iterator> match; + if (regex_search (begin (request), end (request), match, re)) + return match.str (1); + return {}; + } + +void Http_Server::process_message (vector &&request, + int const socket) + { + static const regex protocol_re + {"^(GET|POST|OPTIONS)[[:space:]]+([^[:space:]?]+)([?]([^[:space:]]*))?"}; + + match_results::iterator> match {}; + if (! regex_search (begin (request), end (request), match, protocol_re)) + { + Http_Server::return_bad (socket); + return; + } + + auto callback = service_methods.find (match.str(2) [0] == '/' + ? match.str(2).substr (1) + : match.str(2)); + + if (callback == end (service_methods)) + { + Http_Server::return_bad (socket); + return; + } + + + Query_String QS; + + /* We need to extract this in advance as we will destroy the request + * buffer when we manufacture the Query_String object. */ + const string access_url { extract_header (request, "Origin") }; + + if (match.str (1) == "OPTIONS") + { + std::ostringstream O; + O << "HTTP/1.1 200 OK\r\n" + << "Access-Control-Allow-Origin: " << access_url << "\r\n" + << "Access-Control-Allow-Methods: POST, GET, OPTIONS\r\n" + << "Access-Control-Max-Age: 86400\r\n\r\n"; + + write (socket, O.str ().data (), O.str ().size ()); + + return; + } + + + /* We need to extract this in advance as we will destroy the request + * buffer when we manufacture the Query_String object. */ + const string cookie { extract_header (request, "Cookie") }; + + if (match.str (1) == "POST") + { + static auto const length_re + = regex {"[\r\n]Content-Length:[[:space:]]*([^\r\n]*)"}; + + auto match = match_results::iterator> {}; + + if (! regex_search + (begin (request), end (request), match, length_re)) + { + Http_Server::return_bad (socket); + return; + } + + auto content_start = int {0}; + + { + static auto const re = regex {"\r\n\r\n"}; + auto match = match_results::iterator> {}; + regex_search (begin (request), end (request), match, re); + content_start = match.position (); + } + + auto const needed_len + = (size_t) (atoi (match.str (1).c_str ()) + content_start + 4); + + auto len = request.size (); + + request.resize (needed_len); + + while (len < needed_len) + { + auto const L + = read (socket, request.data () + len, needed_len - len); + + if (L <= 0) + { + Http_Server::return_bad (socket); + return; + } + + len += L; + } + + scan_multipart (QS, + {begin (request) + content_start + 4, end (request)}); + + QS.post_method = 1; + } + + else /* GET */ + { + QS = query_string (match.str (4)); + } + + if (cookie.length () > 0) QS.add ("__cookie__", cookie); + QS.access_url = access_url; + + (callback->second) (move (QS), socket); + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/http-server.h b/DMBCS/micro-server/http-server.h new file mode 100644 index 0000000..7c3c98a --- /dev/null +++ b/DMBCS/micro-server/http-server.h @@ -0,0 +1,174 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__HTTP_SERVER__H +#define DMBCS__MICRO_SERVER__HTTP_SERVER__H + + +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + /** We understand a HTTP server as a purely functional object: a + * method call with arguments, returning a value which is a function + * only of those arguments and having no other side-effects. The + * prototype URL is + * {host}:{port}/{method}?{par1}={value1}&{par2}={value2}... where + * {host} is obviously us and {port} is supplied to the server + * constructor. The constructor method (\c create) takes one other + * argument: a mapping of {method} names onto function objects; these + * are called with a set of parameters as distilled from the URL, and + * a socket to which the function is expected to send the + * corresponding reply. Convenience methods are provided by this + * class to help with the composition of those replies, and all + * functions should conclude their work by calling one of these + * methods. + * + * Thus there are two functions which the application is immediately + * concerned with: the \c create function which returns a + * fully-constructed \c Http_Server object given a map of method names + * to functions and a local port number on which to operate, and the \c + * tick function which causes the server to operate for a single + * interaction with some client. The application should call this \c + * tick method frequently so that the server can function as required. + * + * The rest of the interesting functions are the \c return_* functions, + * which will send to a given \c client_socket a fully-formed HTTP + * response carrying a payload of various type: PNG image, JSON data, + * or HTML web pages. */ + + struct Http_Server : Tcp_Server + { + /** The type of function-thing which implements the brawn behind a + * particular service call. */ + using Service_Method = function; + + + /** The type of object which holds the correspondence between server + * method names and the C++ function objects which implement the + * methods. */ + using Service_Methods = map; + + + Service_Methods service_methods; + + + /** The sole object constructor. Creates a ready-to-use server object + * which operates the HTTP protocol on the local \a port, and will + * call out to functions in the \a methods object. The only action + * which can be performed on this object is to pass it to the \c tick + * function below, allowing the server to perform a small unit of + * work. */ + Http_Server (uint16_t const port, Service_Methods &&methods) + : Tcp_Server {port}, service_methods {move (methods)} + {} + + + void process_message (vector &&message, + int const socket) override; + + + + /* !!!! We need to question whether we want this or not. */ + static string add_html_headers (string const &&); + + + + /** Convenience function allowing a server method to send a \a html + * page back to the client on the given \a client_socket. */ + static void return_html (int const client_socket, string const &html); + + + /** Convenience function allowing a server method to send a \a text + * page back to the client on the given \a client_socket. */ + static void return_text (int const client_socket, string const &text); + + + /** Convenience function allowing a server method to send a \a CSS + * specification back to the client on the given \a client_socket. */ + static void return_css (int const client_socket, string const &text); + + + /** Convenience function allowing a server method to send a \a pdf + * document back to the client on the given \a client_socket. */ + static void return_pdf (int const client_socket, string const &pdf); + + + /** Convenience function allowing a server method to send a \a json + * data structure back to the client on the given \a + * client_socket. */ + static void return_json (int const client_socket, string const &json, + const string_view origin_url); + + + /** Convenience function allowing a server method to send a response + * to a bad request to the client. Note that we actually send a good + * response of an empty payload in this case (we have got this far; + * as far as the HTTP protocol is concerned any well-formatted + * response from us is a good one, even if it signals failure of the + * server to produce meaningful results). */ + static void return_bad (int const client_socket); + + + /** Convenience function allowing a server method to send a \a png + * image back to the client on the given \a client_socket. The \a + * png should be provided by the \c Png class available with this + * library. */ + static void return_png (int const client_socket, + vector const &png); + + + /** Convenience function allowing a server method to send a \a svg + * image back to the client on the given \a client_socket. The \a + * png should be provided by the \c Png class available with this + * library. */ + static void return_svg (int const client_socket, + string const &svg); + + + } ; /* End of class Http_Server. */ + + +} } /* End of namespace DMBCS::Micro_Server. */ + + + +inline void add (DMBCS::Micro_Server::Http_Server &S, + std::string &&method_name, + DMBCS::Micro_Server::Http_Server::Service_Method &&M) +{ S.service_methods.emplace (method_name, M); } + + + +inline bool tick (DMBCS::Micro_Server::Http_Server &S, + const std::chrono::system_clock::duration& wait) +{ return S.tick (wait); } + + + +#include + + +#endif /* Undefined DMBCS__MICRO_SERVER__HTTP_SERVER__H. */ diff --git a/DMBCS/micro-server/hyper-tags.cc b/DMBCS/micro-server/hyper-tags.cc new file mode 100644 index 0000000..c37918b --- /dev/null +++ b/DMBCS/micro-server/hyper-tags.cc @@ -0,0 +1,171 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + /* Note that we need to take a copy of the replacement texts, since it + * is understood that the original _reg_ is to be left intact. */ + + Hyper_Tags &Hyper_Tags::add (Hyper_Tags const ®, int const harden) + { + for (auto i : reg.tags) + { + add (i.name, i.replacement); + + if (harden) harden_last (); + } + + return *this; + } + + + + Hyper_Tags &Hyper_Tags::add (string const &tag, + double const &value, + int const precision) + { + auto hold = ostringstream {}; + hold << setprecision (precision) << value; + return add (tag, hold.str ()); + } + + + void Hyper_Tags::add_date (string const &tag, + time_t const &time, + string const &format) + { + array buffer; + strftime (& buffer [0], buffer.size (), format.c_str (), localtime (&time)); + add (tag, & buffer [0]); + } + + + Hyper_Tags & Hyper_Tags::add_query (Query_String const &Q) + { + for (auto const &q : Q) add (q.first, q.second); + return *this; + } + + + + void Hyper_Tags::add_passthrough_tag (Query_String const &query_string, + ...) + { + va_list arguments; va_start (arguments, query_string); + + auto acc = string {}; + + const char *query_name; + + while ((query_name = va_arg (arguments, const char*))) + { + auto const query_value = query_string.get (query_name, string {}); + + if (query_value.length ()) + { + acc += string {""; + } + } + + add ("pass-through", move (acc)); + + va_end (arguments); + } + + + + string Hyper_Tags::substitute_ (string &&input, int repeat) + { + while (repeat-- > 0) + { + for (auto const &i : sections) + input = remove_tags (i.name, move (input), i.keep == LOSE_SECTION); + + for (auto const &i : tags) + { + auto hold = ostringstream {}; + hold << '[' << i.name << "/]"; + input = transform (move (input), hold.str (), i.replacement); + } + } + + return input; + } + + + + string Hyper_Tags::remove_tags (string const &tag_name, + string &&input, + bool const &whole_section) + { + auto const open_tag = "[" + tag_name + "]"; + auto const close_tag = "[/" + tag_name + "]"; + + for (auto start_end = input.find (close_tag); + start_end != input.npos; + start_end = input.find (close_tag)) + { + auto const start_open = input.rfind (open_tag, start_end); + + if (start_open == input.npos) return input; + + if (whole_section) + input.erase (start_open, + start_end + close_tag.length () - start_open); + + else + { + input.erase (start_end, close_tag.length ()); + input.erase (start_open, open_tag.length ()); + } + } + + return input; + } + + + + string Hyper_Tags::strip_loose_tags (string&& in) + { + static const regex re {"\\[[-!_[:alnum:]]*/\\]"}; + cmatch match {}; + for (int i = 0; + regex_search (in.c_str () + i, match, re); + i += match.position ()) + in.erase (i + match.position (), match.length ()); + return in; + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/hyper-tags.h b/DMBCS/micro-server/hyper-tags.h new file mode 100644 index 0000000..dcf2b0f --- /dev/null +++ b/DMBCS/micro-server/hyper-tags.h @@ -0,0 +1,200 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__HYPER_TAGS__H +#define DMBCS__MICRO_SERVER__HYPER_TAGS__H + + +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + using namespace std; + + + struct Hyper_Tags + { + /* A tag is an entry on a HTML template of the form [xxx/], which is + * to be replaced with some dynamic content. */ + + struct Tag + { + string name; + string replacement; + } ; + + + /* A section is part of a HTML template surrounded by strings of the + * form [xxx] and [/xxx]; either the whole section will be eliminated + * (LOSE_SECTION) or just the surrounding tags will be stripped + * leaving the content of the section in place (KEEP_SECTION). */ + + enum Section_Keep { KEEP_SECTION = 1, LOSE_SECTION = 0 } ; + + struct Section + { + string name; + Section_Keep keep; + } ; + + + /* New tags are inserted at the front of the list, so normally they + * override older tag definitions. This can be overridden by making a + * new tag `hard', when the last_tag pointer will be placed after it, + * and all future additions to the registry will go in *after* the + * hard tags, and thus will *not* override the earlier meaning. */ + + list tags; + + list::iterator last_hard; /* Actually, the first ‪`soft'. */ + + vector
sections; + + + Hyper_Tags () : last_hard {begin (tags)} {} + Hyper_Tags (Hyper_Tags const &) = delete; + Hyper_Tags (Hyper_Tags &&) = default; + Hyper_Tags &operator= (Hyper_Tags const &) = delete; + Hyper_Tags &operator= (Hyper_Tags &&) = default; + + + static string remove_tags (string const &tag_name, + string &&input, + bool const &whole_section); + + + Hyper_Tags §ion (string const &name, Section_Keep const &keep) + { + sections.push_back (Section {name, keep}); + sections.push_back (Section {"!" + name, + keep ? LOSE_SECTION : KEEP_SECTION}); + return *this; + } + + + void harden_last () { if (last_hard != end (tags)) ++last_hard; } + + + bool has (string const &a) const + { + return find_if (begin (tags), end (tags), [&a] (Tag const &T) + { return T.name == a; }) + != end (tags); + } + + Hyper_Tags &add (Hyper_Tags const ®istry, int const harden = 0); + + Hyper_Tags &operator+= (const Hyper_Tags &tags) { return add (tags); } + + + Hyper_Tags &add (const string &tag, + string &&substitution_text) + { last_hard = tags.insert (last_hard, + Tag {tag, move (substitution_text)}); + return *this; } + + template + Hyper_Tags &add (string const &tag, T const &value) + { + ostringstream hold; + hold << value; + return add (tag, hold.str ()); + } + + Hyper_Tags &add + (string const &tag, double const &value, int const precision = 4); + + template + Hyper_Tags &add (const string &tag, Query_String &qs, const T &fallback) + { add (tag, qs.get (tag, fallback)); return *this; } + + Hyper_Tags &add_query (Query_String const &); + + + /* The tag is replaced with a string consisting of a comma-separated + * (no spaces) list of integers. */ + + template + void add_int_list (const string &tag, Iterator begin, Iterator end); + + void add_date (const string &tag, + const time_t &time, + const string &format); + + void add_file (const string &tag, const string &file_name) + { add (tag, slurp_file (file_name)); } + + + /* The trailing arguments are a list of const char *const, terminated + * with nullptr. */ + void add_passthrough_tag (const Query_String& query_string, ...) + __attribute__ ((sentinel)); + + Hyper_Tags& keep_section (const string& name, const bool keep = 1) + { return section (name, keep ? KEEP_SECTION : LOSE_SECTION); } + + Hyper_Tags& lose_section (const string& name, const bool lose = 1) + { return section (name, lose ? LOSE_SECTION : KEEP_SECTION); } + + string substitute_ (string&& html_template, int repeat); + + static string strip_loose_tags (string&&); + + } ; /* End of class Hyper_Tags. */ + + + + template + inline void Hyper_Tags::add_int_list (const string &tag_name, + Iterator begin, + Iterator end) + { + auto acc = ostringstream {}; + acc << *begin; + for (++begin; begin != end; ++begin) acc << ',' << *begin; + add (tag_name, acc.str ()); + } + + +} } /* End of namespace DMBCS::Micro_Server. */ + + + +inline std::string substitute (DMBCS::Micro_Server::Hyper_Tags &tags, + std::string &&html_template, + int repeat = 1) +{ return tags.substitute_ (std::move (html_template), repeat); } + + + +inline std::string substitute (std::string &&html_template, + DMBCS::Micro_Server::Hyper_Tags &tags, + int repeat = 1) +{ return tags.substitute_ (std::move (html_template), repeat); } + + + +#endif /* Undefined DMBCS__MICRO_SERVER__HYPER_TAGS__H. */ diff --git a/DMBCS/micro-server/makefile.am b/DMBCS/micro-server/makefile.am new file mode 100644 index 0000000..c9f2e92 --- /dev/null +++ b/DMBCS/micro-server/makefile.am @@ -0,0 +1,45 @@ +# dmbcs-micro-server A C++ library providing CGI or built-in +# web server functions +# +# Copyright (C) 2018 DM Bespoke Computer Solutions Ltd +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or (at +# your option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + + + +incdir = ${prefix}/include/DMBCS/micro-server +inc2dir = ${prefix}/include/DMBCS + +AM_CXXFLAGS = -Wall -Wextra -I${top_srcdir} \ + -DMAC='"@MAC@"' \ + ${CURLPP_CFLAGS} -std=c++2a + +AM_LIBS = ${CURLPP_LIBS} + +lib_LTLIBRARIES = libdmbcs-micro-server.la + +dmbcs_classes = http-server \ + hyper-tags \ + query-string \ + tcp-server \ + udp-server \ + utils + +libdmbcs_micro_server_la_SOURCES = ${dmbcs_classes:=.cc} + +inc_HEADERS = ${dmbcs_classes:=.h} micro-server.h http-server--impl.h + +inc2_HEADERS = micro-server.h + +MAINTAINERCLEANFILES = makefile.in diff --git a/DMBCS/micro-server/micro-server.h b/DMBCS/micro-server/micro-server.h new file mode 100644 index 0000000..9d6156f --- /dev/null +++ b/DMBCS/micro-server/micro-server.h @@ -0,0 +1,31 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__MICRO_SERVER__H +#define DMBCS__MICRO_SERVER__MICRO_SERVER__H + +#include +#include +#include +#include +#include + +#endif /* Undefined DMBCS__MICRO_SERVER__MICRO_SERVER__H. */ diff --git a/DMBCS/micro-server/query-string.cc b/DMBCS/micro-server/query-string.cc new file mode 100644 index 0000000..6b687ed --- /dev/null +++ b/DMBCS/micro-server/query-string.cc @@ -0,0 +1,238 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + static void scan_string (Query_String &Q, string const &a) + { + for (string::size_type name_start = 0; name_start < a.length (); ) + { + auto const name_end = a.find_first_of ("&=", name_start); + + auto const name + = name_end == a.npos ? a.substr (name_start) + : a.substr (name_start, name_end - name_start); + + string::size_type value_end; + + if (name_end == a.npos || a [name_end] == '&') + { + Q [name] = "1"; + value_end = name_end; + } + + else + { + auto const value_start = name_end + 1; + + value_end = a.find ('&', value_start); + + auto const real_end = value_end == a.npos ? a.length () + : value_end; + + Q [name] = decode_url (a.substr (value_start, + real_end - value_start)); + } + + name_start = value_end + + ((value_end != a.npos && a [value_end] == '&') ? 1 : 0); + } + } + + + + void scan_multipart (Query_String &Q, string const &a) + { + auto const boundary_end = a.find_first_of ("\r\n"); + + if (boundary_end == a.npos) + return; + + auto const boundary = "\r\n" + a.substr (0, boundary_end); + + auto last_boundary = size_t {0}; + + for (;;) + { + auto const next_boundary = a.find (boundary, last_boundary + 1); + + if (next_boundary == a.npos) + return; + + auto const name_start = a.find ("name=\"", last_boundary); + + if (name_start == a.npos || name_start > next_boundary) + return; + + auto const name_end = a.find ("\"", name_start + 6); + + if (name_end == a.npos) + return; + + auto const name = a.substr (name_start + 6, + name_end - name_start - 6); + + auto const data_start = a.find ("\r\n\r\n", name_end); + + if (data_start == a.npos) + return; + + if (name == "upload-file") + copy (a.begin () + data_start + 4, + a.begin () + next_boundary, + back_inserter (Q.upload_data)); + + else + Q [name] = a.substr (data_start + 4, + next_boundary - (data_start + 4)); + + last_boundary = next_boundary; + } + } + + + + Query_String get_query_string () + { + auto ret = Query_String {}; + + auto const method = getenv ("REQUEST_METHOD"); + + if (method.empty () || method == "GET") + { + scan_string (ret, getenv ("QUERY_STRING")); + } + + else + { + ret.post_method = 1; + + auto const input_length = atoi (getenv ("CONTENT_LENGTH").c_str ()); + + auto line = string {}; + + for (int i = 0; i < input_length; ++i) + line += getchar (); + + if (line [0] == '-' && line [1] == '-') + scan_multipart (ret, line); + + else + scan_string (ret, line); + } + + return ret; + } + + + + Query_String query_string (string const &input) + { + Query_String ret; + scan_string (ret, input); + return ret; + } + + + + string query_string (Query_String const &Q) + { + if (Q.empty ()) return string {}; + + auto separator = string {}; + auto ret = string {}; + + for (auto const &i : Q) + { + ret += separator + i.first + '=' + i.second; + separator = "&"; + } + + return ret; + } + + + + vector Query_String::get_list (string const &name) const + { + auto ret = vector {}; + + char comma; + + auto s = istringstream {get (name, string ())}; + + for (;;) + { + int k; s >> k; + + if (s) + { + ret.push_back (k); + s >> comma; + } + + else + return ret; + } + } + + + + void Query_String::make_list (string const &name, + vector const &list) + { + if (list.empty ()) return; + + auto hold = ostringstream {}; + + hold << list.front (); + + for (auto i = list.begin () + 1; i != list.end (); ++i) + hold << "," << *i; + + (*this) [name] = hold.str (); + } + + + + vector Query_String::get_checked_array (string const &name_prefix) + const + { + auto ret = vector {}; + + for (auto i : *this) + if (name_prefix == i.first.substr (0, name_prefix.length ())) + ret.push_back (atol (i.first.substr (name_prefix.length ()).c_str ())); + + return ret; + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/query-string.h b/DMBCS/micro-server/query-string.h new file mode 100644 index 0000000..e5fdff6 --- /dev/null +++ b/DMBCS/micro-server/query-string.h @@ -0,0 +1,194 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__QUERY_STRING__H +#define DMBCS__MICRO_SERVER__QUERY_STRING__H + + +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + /* An object designed to hold the (name, value) pairs passed to a GCI + * program through the query part of the URL, and carries along with it + * the information of whether query string came from a HTTP POST or GET + * method, and if a message authentication code (MAC) was verified on + * the URL. There is also the possibility that the object holds the + * contents of an uploaded file, if such was sent from a POSTed HTML + * form. + * + * The chief methods are the /has/ and /get/ methods, to determine if a + * query string has a given value, and to get a value (which may be + * interpreted as any numeric or string type) returning some default if + * it is not there. + * + * The main functions are the /query_string/s which produces a + * Query_String object from a CGI programʼs environment (as + * appropriate), and conversely produce a URI fragment with the + * contents of a given Query_String object. */ + + struct Query_String : map + { + /* The secret mixed into a URL before computing a cryptographic + * fingerprint. The value assigned here comes from the top-level + * configure script via the local makefile. */ + static constexpr char const * MAC_KEY = MAC; + + /* Either the HTTP method was POST, or else we assume GET. */ + bool post_method {0}; + + /* Either the query contained a verified MAC, or it didnʼt. */ + bool mac_verified_ {0}; + + /* Will be empty unless this was a multipart POST with an uploaded + * file in it. */ + vector upload_data; + + /* If we have been called from a browser exercising cross-site access + * control, this is the URL of the other site from which we will allow + * access. */ + string access_url; + + + /* Allow all bulk operations except copy, which might get a tad + * expensive if done in the wrong place. */ + Query_String () = default; + Query_String (Query_String &) = delete; + Query_String (Query_String &&) = default; + Query_String &operator= (Query_String const &) = delete; + Query_String &operator= (Query_String &&) = default; + + + /* Add a new parameter to this query set, with the given name and + * value. */ + template + void add (string const &name, T const &value) + { ostringstream hold; hold << value; add (name, hold.str ()); } + + + /* Add a new parameter to this query set, with the given name and a + * value pulled from a parameter with that same name in the input + * query string, or else use the fallback as the value. */ + template + void add (string const &name, + Query_String const &input, + T const &fallback) + { add (name, input.get (name, fallback)); } + + + /* Return TRUE if the HTTP request indicated a POST method, else + * return FALSE. */ + bool posted () const { return post_method; } + + + /* Return TRUE only if this query had a MAC which we have verified. */ + bool mac_verified () const { return mac_verified_; } + + + /* Return TRUE only if this query has a parameter with the given + * name. */ + bool has (string const &name) const { return find (name) != end (); } + + + /* Get the value of the parameter with the given name in this query; + * use the fallback value if this procedure fails (the fallback is + * also useful to establish the desired return type, which may be any + * numerical or string type). */ + template + T get (string const &name, T const &fallback = {}) const; + + + /* If the value of a parameter is a comma-separated list of integers, + * the list is returned as a vector. (This is the only list case we + * currently implement; others may appear in future versions. */ + vector get_list (string const &name) const; + + + /* Add a comma-separated list of integers to /this/ object. */ + void make_list (string const &name, vector const &list); + + + /* If the parameters which start with the given name are present, the + * remainder of the name should be a numerical sequence and the + * numerical values of all these parameters are returned in the + * unsorted vector of ints. */ + vector get_checked_array (string const &name) const; + } ; + + + + /* Manufacture a Query_String according to environment variables and/or + * standard input, as directed by the CGI specification. */ + Query_String get_query_string (); + + /* Manufacture a Query_String object to reflect the URI parameter list + * found in the input. */ + Query_String query_string (string const & input); + + /* Create a URI parameter list with the data held in the Query_String, + * and add a guarding MAC to the end. */ + string query_string_with_mac (Query_String const &); + + /* Create a URI parameter list with the data held in the Query_String + * (no MAC will be present). */ + string query_string (Query_String const &); + + void scan_multipart (Query_String &Q, string const &a); + + + + /********************* IMPLEMENTATION ***********************/ + + template <> + inline string Query_String::get (string const &name, + string const &fallback) const + try { return at (name); } + catch (out_of_range&) { return fallback; } + + + template + inline T Query_String::get (string const &name, T const &fallback) const + try { if (at (name).length () == 0) return fallback; + T ret; istringstream {at (name)} >> ret; return ret; } + catch (out_of_range&) { return fallback; } + + + template <> + inline void Query_String::add (string const &name, string const &value) + { (*this) [name] = value; } + + + template<> inline void + Query_String::add (string const &name, Query_String const &input_query) + { add (name, input_query.get (name, string {})); } + + +} } /* End of namespace DMBCS::Micro_Server. */ + + +#endif /* Undefined DMBCS__MICRO_SERVER__QUERY_STRING__H. */ diff --git a/DMBCS/micro-server/tcp-server.cc b/DMBCS/micro-server/tcp-server.cc new file mode 100644 index 0000000..a27db89 --- /dev/null +++ b/DMBCS/micro-server/tcp-server.cc @@ -0,0 +1,202 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include +#include +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + +/* Used also by Udp_Server. */ + +int Tcp_Server::bind_socket (uint16_t const port, int const socket_type) + { + const int listen_socket = socket (AF_INET, socket_type, 0); + + int option = 1; + setsockopt (listen_socket, SOL_SOCKET, SO_REUSEADDR, (char*)&option, + sizeof (option)); + + sockaddr_in addr; + addr.sin_family = AF_INET; + addr.sin_port = htons (port); + addr.sin_addr.s_addr = INADDR_ANY; + + if (::bind (listen_socket, (sockaddr const *) &addr, sizeof (addr))) + throw runtime_error {"cannot bind to port " + std::to_string (port)}; + + return listen_socket; + } + + + +Tcp_Server::Tcp_Server (uint16_t const port) + { + listen_socket = bind_socket (port, SOCK_STREAM); + listen (listen_socket, 5); + } + + + +bool Tcp_Server::tick (const chrono::system_clock::duration& wait, + fd_set& read_socket_set, + std::function fallout) + { + append_to_fdset (*this, &read_socket_set); + + timeval t {chrono::duration_cast (wait).count (), + chrono::duration_cast (wait).count () + % 1'000'000}; + + auto const test + = select (FD_SETSIZE, &read_socket_set, nullptr, nullptr, &t); + + if (-1 == test) + { + if (EINTR == errno) + throw runtime_error {"program interrupted"}; + else + throw runtime_error {"TCP server socket problem"}; + } + + if (0 == test) + return 0; + + if (FD_ISSET (listen_socket, &read_socket_set)) + { + sockaddr_in addr; + socklen_t size = sizeof (addr); + int sock = accept (listen_socket, (sockaddr*) &addr, &size); + client_sockets [sock] = addr; + return 1; + } + + for (auto const c : client_sockets) + if (FD_ISSET (c.first, &read_socket_set)) + { + /* !! Hardwire, hard limit. */ + auto const len = read (c.first, + message_buffer.data (), + message_buffer.size ()); + + if (len < 0) + { + std::cerr << strerror (errno); + close (c.first); + client_departed (c.first); + client_sockets.erase (c.first); + } + + else if (! len) + { + close (c.first); + client_departed (c.first); + client_sockets.erase (c.first); + } + + else + process_message ({begin (message_buffer), + begin (message_buffer) + len}, + c.first); + + return 1; + } + + fallout (read_socket_set); + return 1; + } + + + +bool Aggregate_Ticker::operator() + (const chrono::system_clock::duration& wait) + { + fd_set fds; + FD_ZERO (&fds); + int top {0}; + + for (auto &T : servers) + top = std::max (top, append_to_fdset (*T, &fds)); + + timeval t { chrono::duration_cast (wait).count (), + chrono::duration_cast (wait).count () + % 1'000'000}; + + auto const test = select (FD_SETSIZE, &fds, nullptr, nullptr, &t); + + if (-1 == test) + { + if (EINTR == errno) throw runtime_error {"program interrupted"}; + else + throw runtime_error {"server socket problem, errno=" + + std::to_string (errno)}; + } + + if (0 == test) return 0; + + for (auto &T : servers) + if (T->tick (chrono::microseconds {0})) + return 1; + + return 0; + } + + + + int append_to_fdset (Tcp_Server const &tcp, + fd_set *const set) + { + FD_SET (tcp.listen_socket, set); + for (auto const &S : tcp.client_sockets) FD_SET (S.first, set); + return std::max (tcp.listen_socket, begin (tcp.client_sockets)->first); + } + + + + fd_set provide_fdset (Tcp_Server const &tcp) + { + fd_set ret; + FD_ZERO (&ret); + append_to_fdset (tcp, &ret); + return ret; + } + + + + uint16_t listener_port (const Tcp_Server& T) + { + sockaddr_in addr; + socklen_t len = sizeof (addr); + if (0 != getsockname (T.listen_socket, (sockaddr*) &addr, &len)) + throw std::runtime_error + {"cannot get port of Tcp_Serverʼs listener socket"}; + return ntohs (addr.sin_port); + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/tcp-server.h b/DMBCS/micro-server/tcp-server.h new file mode 100644 index 0000000..8ab9fe0 --- /dev/null +++ b/DMBCS/micro-server/tcp-server.h @@ -0,0 +1,170 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__TCP_SERVER__H +#define DMBCS__MICRO_SERVER__TCP_SERVER__H + + +#include +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + using namespace std; + + + /* A Tcp_Server is an object which listens to a TCP port, accepts + * connections from multiple clients (and disconnections), and takes any + * messages these clients may send to us and hand them off to a + * specialized message despatcher. Real servers will inherit this class + * and provide their own specialized message processor. */ + + struct Tcp_Server + { + /* The socket on which we take new connections. */ + int listen_socket; + + /* All of the connected sockets, kept in _descending_ order so that + * the highest file descriptor of the sockets is immediately to + * hand. */ + map> client_sockets; + + vector message_buffer {vector (10000)}; + + + static int bind_socket (const uint16_t port, const int socket_type); + + + /** The sole object constructor. Creates a ready-to-use server object + * which operates the TCP protocol on the local \a port, and will + * call out to the process_message method when any messages come in. + * The only action which can be performed on this object is to call + * the \c tick method, allowing the server to perform a small unit of + * work. + * + * Will throw a runtime_error if it is not possible to establish the + * listening socket. */ + explicit Tcp_Server (const uint16_t port); + + + /* Boilerplate requirement of destructor of virtual class. */ + virtual ~Tcp_Server () noexcept { close (listen_socket); } + + + + /* A function which must take the message which has come off of the + * wire, do whatever work is required to service the message, and then + * send an appropriate response back to the client, via the given + * socket. */ + virtual void process_message (vector&& message, + const int socket) = 0; + + + /* Will be called when a client disconnects. */ + virtual void client_departed (const int /* socket */) {} + + + /** Cause the server to perform some small unit of work, or wait up to + * /wait/ time for some work requirement to appear. + * + * The return value indicates if any work was done. Will throw a + * runtime_error if the program receives a signal during + * operations. */ + bool tick (const chrono::system_clock::duration& wait, + fd_set& read_socket_set, + std::function fallout); + + + bool tick (const chrono::system_clock::duration& wait) + { + fd_set s {}; FD_ZERO (&s); + return tick (wait, s, nullptr); + } + + + /** Surrender our interest in this socket. The socket itself will + * continue to remain active, but we will no longer be polling it for + * data and returning messages from it. */ + int disown (const int socket) + { client_sockets.erase (socket); return socket; } + + + } ; /* End of class Tcp_Server. */ + + + +/* Find out the TCP port number of the listener socket, to which clients + * can connect. This is necessary if the class was set up with a zero + * port, in which case the operating system would have quietly assigned + * a random port. + * + * Will throw a runtime_error if the operation fails. */ +uint16_t listener_port (const Tcp_Server&); + + +/* Append all listening and connected sockets in the Tcp_Server to the + * fd_set. */ +int append_to_fdset (const Tcp_Server &, fd_set *const); + +inline int append_to_fdset (fd_set *const f, const Tcp_Server& T) +{ return append_to_fdset (T, f); } + + +/* Manufacture an fdset containing the listening socket and all of the + * connected client sockets in the Tcp_Server. */ +fd_set provide_fdset (const Tcp_Server& tcp); + + + + /* This class proxies a set of separate Tcp_Server's, presenting them to + * the application as if they were one. In particular, it allows each + * of the servers equal opportunity to service an incoming message. + * + * NOTE that it is left to the application to destroy the individual + * servers, once an Aggregate_Ticker is destroyed. */ + + struct Aggregate_Ticker + { + vector servers; + + Aggregate_Ticker (vector && s_) : servers {move (s_)} + {} + + bool operator() (const chrono::system_clock::duration& wait); + }; + + + /* Manufacture an Aggregate_Ticker. */ + inline Aggregate_Ticker aggregate_ticker (vector && S) + { return Aggregate_Ticker {move (S)}; } + + +} } /* End of namespace DMBCS::Micro_Server. */ + + +#endif /* Undefined DMBCS__MICRO_SERVER__TCP_SERVER__H. */ diff --git a/DMBCS/micro-server/udp-server.cc b/DMBCS/micro-server/udp-server.cc new file mode 100644 index 0000000..65460f7 --- /dev/null +++ b/DMBCS/micro-server/udp-server.cc @@ -0,0 +1,96 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include +#include /* For bind_socket. */ +#include +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + Udp_Server::Udp_Server (uint16_t const port) + { + listen_socket = Tcp_Server::bind_socket (port, SOCK_DGRAM); + } + + + + bool Udp_Server::tick (std::chrono::system_clock::duration linger) + { + namespace C = std::chrono; + + auto s = provide_fdset (*this); + + timeval t { C::duration_cast (linger).count (), + C::duration_cast (linger).count () + % 1'000'000}; + + auto const test = select (listen_socket + 1, &s, nullptr, nullptr, &t); + + if (-1 == test) + { + if (EINTR == errno) + throw runtime_error {"program interrupted"}; + } + + else if (0 == test) + return 0; + + else if (FD_ISSET (listen_socket, &s)) + { + static char buffer [1500]; + auto const size + = recv (listen_socket, buffer, sizeof (buffer), 0); + + process_message (std::vector + ((uint8_t*) buffer, (uint8_t*) (buffer + size))); + } + + return 1; + } + + + + int append_to_fdset (Udp_Server const &udp, + fd_set *const set) + { + FD_SET (udp.listen_socket, set); + return udp.listen_socket; + } + + + + fd_set provide_fdset (Udp_Server const &udp) + { + fd_set ret; + FD_ZERO (&ret); + append_to_fdset (udp, &ret); + return ret; + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/udp-server.h b/DMBCS/micro-server/udp-server.h new file mode 100644 index 0000000..d646ac8 --- /dev/null +++ b/DMBCS/micro-server/udp-server.h @@ -0,0 +1,100 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__UDP_SERVER__H +#define DMBCS__MICRO_SERVER__UDP_SERVER__H + + +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + using namespace std; + + + /* A Tcp_Server is an object which listens to a TCP port, accepts + * connections from multiple clients (and disconnections), and takes any + * messages these clients may send to us and hand them off to a + * specialized message despatcher. Real servers will inherit this class + * and provide their own specialized message processor. */ + + struct Udp_Server + { + /* The socket on which we take new connections. */ + int listen_socket; + + string buffer; + + + /** The sole object constructor. Creates a ready-to-use server object + * which operates the TCP protocol on the local \a port, and will + * call out to the process_message method when any messages come in. + * The only action which can be performed on this object is to call + * the \c tick method, allowing the server to perform a small unit of + * work. */ + explicit Udp_Server (uint16_t const port); + + + /* Boilerplate requirement of destructor of virtual class. */ + virtual ~Udp_Server () = default; + + + /* A function which must take the message which has come off of the + * wire, do whatever work is required to service the message, and then + * send an appropriate response back to the client, via the given + * socket. */ + virtual void process_message (std::vector &&) = 0; + + + /** Cause the server to perform some small unit of work, or wait up to + * /wait/ time for some work requirement to appear. + * + * The return value indicates if any work was done. */ + bool tick (std::chrono::system_clock::duration); + + + } ; /* End of class Tcp_Server. */ + + + + /* Append all listening and connected sockets in the Tcp_Server to the + * fd_set. */ + int append_to_fdset (Udp_Server const &, fd_set *const); + + inline int append_to_fdset (fd_set *const f, Udp_Server const &U) + { return append_to_fdset (U, f); } + + + /* Manufacture an fdset containing the listening socket and all of the + * connected client sockets in the Tcp_Server. */ + fd_set provide_fdset (Udp_Server const &); + + +} } /* End of namespace DMBCS::Micro_Server. */ + + +#endif /* Undefined DMBCS__MICRO_SERVER__UDP_SERVER__H. */ diff --git a/DMBCS/micro-server/utils.cc b/DMBCS/micro-server/utils.cc new file mode 100644 index 0000000..454c029 --- /dev/null +++ b/DMBCS/micro-server/utils.cc @@ -0,0 +1,181 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#include +#include +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + string slurp_file (ifstream& input) + { + input.seekg (0, ios::end); + string line (input.tellg (), char {}); + input.seekg (0, ios::beg); + input.read (line.data (), line.length ()); + return line; + } + + + + string slurp_file_with_error (const string& file_name) + { + ifstream input {file_name}; + if (! input.good ()) throw Slurp_Error {file_name}; + return slurp_file (input); + } + + + + string slurp_file (string const & file_name) + try { return slurp_file_with_error (file_name); } + catch (Slurp_Error&) + { + cerr << "SLURP FILE NOT FOUND: ‘" << file_name << "’" << endl; + return {}; + } + + + + string transform (string && in, + string const &find, + string const &replace) + { + for (auto i = string::size_type {0}; + (i = in.find (find, i)) != in.npos; + i += replace.length ()) + in.replace (i, find.length (), replace); + + return in; + } + + + + string htmlize_quotes (string && input) + { + return transform (move (input), "\"", """); + } + + + + string escape_quotes (string && a) + { + return transform (transform (transform (move (a), "\\", "\\\\"), + "'", "\\\'"), + "\"", "\\\""); + } + + + + string decode_url (string && url) + { + url = transform (move (url), "+", " "); + + for (string::size_type i = 0; (i = url.find ('%', i)) != url.npos; ++i) + { + if (i < url.length () - 1 && url [i + 1] == '%') + { + url.erase (i); + } + + else if (i < url.length () - 2 && isxdigit (url [i+1]) + && isxdigit (url [i+2])) + { + url [i] = (char) strtol (url.substr (i+1, 2).c_str (), 0, 16); + url.erase (i + 1, 2); + } + } + + return url; + } + + + + string strip_leading_space (string && in) + { + auto start_space = string::size_type {0}; + + for (;;) + { + /* Scan for first newline which is immediately followed by more white + space (this is the candidate for removal). */ + while (start_space < in.length () - 1 + && (in [start_space] != '\n' + || !isspace (in [start_space + 1]))) + ++ start_space; + + if (start_space >= in.length () - 1) + return in; + + /* Want to leave one space behind. */ + auto start_text = string::size_type {start_space += 2}; + + while (start_text < in.length () && isspace (in [start_text])) + ++ start_text; + + in.erase (start_space, start_text - start_space); + } + + return in; + } + + + + string htmlize (string && entry) + { + static auto const A = vector > + { {'&', "&"}, {'"', """}, + /*{'%', "%"},*/ + {'<', "<"}, {'>', ">"} } ; + + for (auto &i : A) + entry = transform (move (entry), string {i.first}, i.second); + + return entry; + } + + + + string hexalize (unsigned char const *const buffer, + size_t const buffer_size) + { + auto ret = string (2 * buffer_size, ' '); + + for (size_t i = 0; i < buffer_size; ++i) + sprintf (ret.data () + 2 * i, "%2.2x", (unsigned int) buffer [i]); + + return ret; + } + + + + string getenv (string const & env) + { + auto const a = ::getenv (env.c_str ()); + return a ? string {a} : string {}; + } + + +} } /* End of namespace DMBCS::Micro_Server. */ diff --git a/DMBCS/micro-server/utils.h b/DMBCS/micro-server/utils.h new file mode 100644 index 0000000..71d9d5d --- /dev/null +++ b/DMBCS/micro-server/utils.h @@ -0,0 +1,90 @@ +/* + * dmbcs-micro-server A C++ library providing CGI or built-in + * web server functions + * + * Copyright (C) 2018 DM Bespoke Computer Solutions Ltd + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +#ifndef DMBCS__MICRO_SERVER__UTILS__H +#define DMBCS__MICRO_SERVER__UTILS__H + + +#include +#include +#include + + +namespace DMBCS { namespace Micro_Server { + + + using namespace std; + + + /* Get a string containing the entire contents of the file at file_name. + * If there is a problem reading this file then the Slurp_Error will be + * thrown. */ + struct Slurp_Error : runtime_error + { Slurp_Error () : runtime_error {"file slurp error"} {} + explicit Slurp_Error (const string& file_name) + : runtime_error {"file slurp error: ‘" + file_name + "’"} {} } ; + string slurp_file_with_error (string const &file_name); + + /* Read the entire contents of the file at file_name, returning an + * empty string object if this cannot be done. */ + string slurp_file (string const &file_name); + + /* Read the entire contents of the file attached to the input stream, + * returning an empty string object if this cannot be done. */ + string slurp_file (ifstream &file_name); + + /* Replace _all_ occurences of ‘find’ with ‘replace’. */ + string transform (string &&, string const &find, string const &replace); + + /* Replace _all_ occurences of dog-ears with the corresponding HTML + * entity. */ + string htmlize_quotes (string &&); + + /* Make sure the given string displays verbatim in HTML pages. */ + string htmlize (string &&); + + /* To remove the network wastage of sending indented HTML, this function + * replaces any spaces at the start of a line with a single space (just + * in case this is significant to the parsing of the document). */ + string strip_leading_space (string &&); + + /* Replace apostrophes, dog-ears and the escape back-slash with + * escaped versions. */ + string escape_quotes (string &&); + + /* Expand out all space-plusses and unicode markers to their correct + * character representatives. */ + string decode_url (string &&); + + /* Return a hex-string representation of the data values in the buffer. + * The return string will be exactly twice buffer_size long. */ + string hexalize (unsigned char const *const buffer, + size_t const buffer_size); + + /* Return the value of the environment variable env if possible, or else + * just return an empty string. */ + string getenv (string const & env); + + +} } /* End of namespace DMBCS::Micro_Server. */ + + +#endif /* Undefined DMBCS_DMBCS__MICRO_SERVER__UTILS__H. */ diff --git a/NEWS b/NEWS new file mode 100644 index 0000000..e69de29 diff --git a/README b/README new file mode 100644 index 0000000..e69de29 diff --git a/configure.ac b/configure.ac new file mode 100644 index 0000000..3ed9362 --- /dev/null +++ b/configure.ac @@ -0,0 +1,69 @@ +# dmbcs-micro-server A C++ library providing CGI or built-in +# web server functions +# +# Copyright (C) 2018 DM Bespoke Computer Solutions Ltd +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or (at +# your option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + + +# Process this file with autoconf to produce a configure script. + +AC_PREREQ(2.69) +AC_INIT([dmbcs-micro-server], [0.2], [http://rdmp.org/dmbcs/contact]) +AM_INIT_AUTOMAKE +AM_SILENT_RULES([yes]) +AC_CONFIG_SRCDIR([DMBCS/micro-server/query-string.cc]) +AC_CONFIG_MACRO_DIR([m4]) + +# Checks for programs. +AC_PROG_LIBTOOL +AC_PROG_CXX +AC_PROG_AWK +AC_PROG_CC +AC_PROG_CPP +AC_PROG_INSTALL +AC_PROG_LN_S +AC_PROG_MAKE_SET + +# Checks for libraries. +PKG_CHECK_MODULES([CURLPP], [curlpp]) +AC_SEARCH_LIBS([gcry_md_open], [gcrypt]) + +# Configure-time program parameters. +AC_ARG_WITH([mac], + AS_HELP_STRING([--with-mac], + [The secret to create the URL MACs]), + MAC=$withval, + AC_MSG_WARN([using default MAC (use --with-mac to change)]) + MAC="theuas.") + +AC_SUBST([MAC]) + +# Checks for header files. +AC_CHECK_HEADERS([netinet/in.h sys/socket.h unistd.h]) + +# Checks for typedefs, structures, and compiler characteristics. +AC_CHECK_HEADER_STDBOOL +AC_C_INLINE +AC_TYPE_SIZE_T +AC_TYPE_UINT16_T +AC_TYPE_UINT8_T + +# Checks for library functions. +AC_CHECK_FUNCS([select socket strtol]) + +AC_CONFIG_FILES([DMBCS/micro-server/makefile + makefile + dmbcs-micro-server.pc]) +AC_OUTPUT diff --git a/dmbcs-micro-server.pc.in b/dmbcs-micro-server.pc.in new file mode 100644 index 0000000..643185f --- /dev/null +++ b/dmbcs-micro-server.pc.in @@ -0,0 +1,11 @@ +prefix=@prefix@ +exec_prefix=${prefix} +libdir=${exec_prefix}/lib +includedir=${prefix}/include + +Name: dmbcs-micro-server +Description: CGI C++ programming library +Version: @VERSION@ +Requires: curlpp +Libs: -L${libdir} -ldmbcs-micro-server @CURLPP_LIBS@ -lgcrypt +Cflags: -I${includedir} diff --git a/dmbcs-micro-server.texi b/dmbcs-micro-server.texi new file mode 100644 index 0000000..121f25c --- /dev/null +++ b/dmbcs-micro-server.texi @@ -0,0 +1,876 @@ +\input texinfo +@setfilename dmbcs-micro-server.info +@include version.texi +@settitle The dmbcs-micro-server Library Reference Manual +@syncodeindex tp fn +@syncodeindex pg fn + +@copying +This is the reference manual for the dmbcs-micro-server C++ library +(version @value{VERSION}, @value{UPDATED}). + +Copyright @copyright{} 2018 Dale Mellor + +@quotation +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU General Public License as published by the +Free Software Foundation; either version 2 of the License, or (at your +option) any later version. The text of the license can be found in the +section entitled ``Copying''. +@end quotation +@end copying + +@dircategory Libraries +@direntry +* dmbcs-micro-server: (dmbcs-micro-server). C++ CGI utility library. +@end direntry + +@setchapternewpage odd +@titlepage +@title The DMBCS micro-server Library Reference Manual +@subtitle Version @value{VERSION} +@subtitle @value{UPDATED} +@author Dale Mellor + +@page +@vskip 0pt plus 1filll +@insertcopying +@end titlepage + + +@node Top +@summarycontents +@contents +@page + + +@ifnottex +@top The micro-server Library +@insertcopying +@end ifnottex + +@menu +* Introduction:: +* Using the library:: +* Reference:: +* Examples of Use:: +* Hints on how the library might be used in a real application:: + +@detailmenu + --- The Detailed Node Listing --- + +Introduction + +* HTTP Web Services:: +* Our Choice of Name:: +* Your Choice of Library:: +* Outline of Library:: An overview of the library's implementation + +Using the library + + +Reference + +* The utility functions:: +* The Query_String class:: +* The Hyper_Tags class:: +* The Http_Server class:: + +The Query_String class + +* MACs:: +* Constructors:: +* Methods:: +* Functions:: + +The Hyper_Tags class + +* Constructors_:: +* Methods_:: +* Functions_:: + +The Http_Server class + +* Constructor__:: +* Functions__:: + +Examples of Use + +* Simple example -- Online multiplier:: A simple application of the library + +Hints on how the library might be used in a real application + +* Web-site skins:: Web sites which provide a user-selected `look-and-feel' +* Other inheritence:: Other ideas + +@end detailmenu +@end menu + +@node Introduction, Using the library, Top, Top +@chapter Introduction + +This document introduces, defines and exemplifies use of the +dmbcs-micro-server C++ library, providing services to applications for +processing and responding to requests from a web browser, including the +possibility of making the application a stand-alone web server in its +own right (a `micro-server'). + +@menu +* HTTP Web Services:: Introduction to CGI and web servers +* Our Choice of Name:: Use of `DMBCS' +* Your Choice of Library:: Some gentle advice +* Outline of Library:: An overview of the library's implementation +@end menu + +@node HTTP Web Services, Our Choice of Name, Introduction, Introduction +@section HTTP Web Services +A CGI program is a program, written in any language, which conforms to +the Common Gateway Interface (CGI). It is a program executed by a web +server (on the server machine), and is passed information about the +request from the user through the UNIX environment. It is left to the +program to interpret the user's requirements and to produce on its +standard output channel a HTML document which the web server will +relay back to the user's browser for display on his console. + +CGI programs are thus very flexible and amenable to lots of jobs. +Some of them are very small, amounting to only a couple of lines of an +interpreted language to slurp a file from the local storage and send +it straight back to the browser (which is essentially what a web +server would normally do but this allows the programmer to do so in a +more customized way). On the other hand, some CGI programs are +extremely large consisting of hundreds of thousands of lines of code +which may interact with a database and other third-party systems (such +as payment gateways) and do some real work on behalf of the user, +before sending the results of the transactions along for the user's +perusal. + +This project came from a CGI program of the latter description. Because +of its size, complexity and the anticipated load (number of users), it +was decided very early on that it would be written in a proper +programming language which could be compiled optimized to run on the +bare metal of the available computer system, whatever that is. Thus it +would have to be C or C++. While the original implementation had been +in C for political reasons, it has since been ported to the more +convenient C++. As a side-effect of this development, the parts of the +system which deal specifically with the business of being a CGI program +have been abstracted and encapsulated, and then they were syphoned off +into their own separate library; this was further extended to provide +the functions of a self-contained web server. This is now being offered +for general use. + +The result is a library which can be used to inject a self-contained web +server into an arbitrary C++ code base, opening up the interface to such +a legacy program to the modern world, without needing to also build the +infrastructure to serve such a program to the public (although in +practice infrastructure needs to be built for other reasons---like +security and virtualization---but the self-contained scheme allows for +greater flexibility and better functional isolation). + + +@node Our Choice of Name, Your Choice of Library, HTTP Web Services, Introduction +@section Our Choice of Name +The micro-server library was written from scratch since 2004 as part of +a large internet project. The requirement for a C++ framework for +undertaking this task is very common, and thus it is no surprise that +other efforts already exist, notably the GNU cgicc project. + +Some consideration was given to the name of this project. At first it +was going to be called cgicc2, but that carries the implication that +it somehow carries on from the GNU cgicc project, and that it is both +a development and enhancement of it. This is definitely not the case, +but a parallel development, completely different but solving the same +problems. Unfortunately appending any number or even letter carries +some implication of sequencing, and if the two projects continue (as +they should) to be developed then some imbalance would occur in the +rivalry. Such is definitely not the intention, but for the two +projects to be seen as separate. Choice of one or other framework for +any particular project should be based on what the framework offers, +not what letters happen to come in its name. + +Thus it is decided to mark this particular library with the string +'DMBCS': all code appears inside the namespace 'DMBCS::Micro_Server' and +the include file is called 'dmbcs-micro-server.h'; the project is +formally known as the 'dmbcs-micro-server' C++ library. + + +@node Your Choice of Library, Outline of Library, Our Choice of Name, Introduction +@section Your Choice of Library +We offer only this advice: look at the API provided by all the available +libraries, and consider the nature of the working framework (paradigm) +that that implies; choose the library that seems most appropriate for +your project: the one that you will feel most comfortable working with. + + +@node Outline of Library, , Your Choice of Library, Introduction +@section Outline of Library +The library consists of a high-level wrapper and two workhorse classes. +@code{Http_Server} interfaces with multiple clients and delegates +processing of their requests to registered callback functions, which +make direct use of the following workhorses. @code{Query_String} looks +after the part of the CGI interface which passes from the browser to the +CGI program and provides methods specifically for interpreting the +arguments from the browser's query string, and @code{Hyper_Tags} looks +after the part of the CGI interface which passes back from the CGI +program to the browser, and displays the results of the user's request; +this deals with updating template HTML files with some dynamic content +before passing the result to the web server for eventual transmission to +the browser. + + +@node Using the library +@chapter Using the library +To re-iterate: all code in this library comes in the namespace +'DMBCS::Micro_Server' and the header which introduces all of the +functionality is 'dmbcs-micro-server.h'. + +A project would generally consist of a template HTML file with markers +where dynamically-generated content needs to be placed, a .css file +which should be injected into the file or provided by the server as an +inclusion target in the HTML, a .js file containing code that should run +client-side to implement part of the functionality of the web site, and +a (micro-) web server which runs continually, listens for client +connections, and provides generated HTML files and JSON data strings on +demand of the client. + +@menu +@end menu + +@node Reference, Examples of Use, Using the library, Top +@chapter Reference + +@menu +* The utility functions:: Useful functions needed by web applications +* The Query_String class:: For processing the user's arguments +* The Hyper_Tags class:: For substituting dynamic content into HTML +* The Http_Server class:: To implement a micro-server in your own app +@end menu + +@node The utility functions, The Query_String class, Reference, Reference +@section The utility functions +Introductory text here. + +@deftypefun string slurp_file_with_error (const std::string &@var{file_name}) throw (Slurp_Error) + +This function will attempt to open the file named file_name (which may +be a complete path to the file), and read the whole lot into a string. +If any errors occur in the process, a Slurp_Error object will be thrown +(these exception objects do not convey any information back to the +application). +@end deftypefun + +@deftypefun string slurp_file (const std::string &@var{file_name}) + +This function will attempt to open file @var{file_name} (which may be a +full path), and will slurp the entire contents (which are presumably a +hyper-tag'd template file) into a string. If any errors occur, an empty +string will be produced, and a message printed on the standard error +channel to indicate the name of the file which has failed. + +In the majority of applications of this function, in the majority of +calls, the error condition thrown from the function above will not +happen; it would be regarded as an infrastructure build problem rather +than a run-time error if a known file were not accessible. Thus it is +wasteful to worry about and deal with the error at global level--outside +the library--, rather let the program carry on and provide a message to +the user's console about the missing file (the fact that the problem +occurred will be obvious!) Once it is known which file has failed, the +remedy will be equally obvious. +@end deftypefun + +@deftypefun string htmlize_quotes (string && @var{input}) + +Any occurrence of `` in @var{input} will be replaced by `@code{"};' +@end deftypefun + +@deftypefun string htmlize (string && @var{input}) + +All occurrences of HTML-special characters (<>&") will be replaced with +entity representations. + +The main purpose of this method is to alleviate the possibility of +injection attacks into a web-site; if any part of a page is generated +from user-supplied input there is the danger that the user might be +savvy enough to get JavaScript to execute there! But the function is +quite generally useful when it is known that a string needs to appear +verbatim in a web page, regardless of its contents, and thus ought to be +used whenever a string is added to a set of @code{Hyper_Tag}s. +@end deftypefun + +@deftypefun string strip_leading_space (string && @var{input}) + +Replace all sequences of white space at the start of all lines with a +single space character. + +HTML recognizes all sequences of white space outside of quotes as a +single space separator. Thus sequences of white space at the +beginning of lines (which are used by web programmers to give a nice +aesthetic indentation) are a waste of bandwidth. This function will +remove all such occurrences from @var{input}. +@end deftypefun + +@deftypefun string escape_quotes (string @var{input}) + +Replace all occurrences of quotation marks and escapes with escaped +versions, where the escape character is the back-slash. + +This function will put an escape ('\') in front of ''', '''', or '\' +which occur in @var{input}, and is useful (essential when dealing with +user-supplied input) to ensure that strings do not mess up SQL +statements. +@end deftypefun + +@deftypefun string decode_url (string @var{url}) + +This function will replace '+' with ' ', and any %-escaped character +codes in the @var{url} with the ASCII equivalent. + +This will produce a plain string, decoded from strings passed from forms +or EcmaScript on web pages passed through parameter lists in URI's, as +provided within the context of this library by the @code{Query_String} +object. +@end deftypefun + +@deftypefun string hexalize (unsigned char const *const @var{buffer}, size_t const @var{buffer_size}) + +Return an ASCII string containing the hexadecimal representation of the +octets in the given @var{buffer}. The @var{buffer_size} is the number of +octets to decode. +@end deftypefun + +@deftypefun string getenv (string const & @var{env}) + +Return the value of the environment variable called @var{env}, or an +empty string if the variable does not exist in the environment. + +This is a convenience wrapper around the system @code{getenv} call, +adapting it to the use of strings. +@end deftypefun + +@node The Query_String class +@section The Query_String class +A Query_String object is a std::map object +in which the keys are the variables passed in the URL query string +part and the values are the values from that query string. Methods +are defined which interrogate the class in details more specific to +the CGI problem, and allow for values to be extracted in either string +or a numeric form, as expected by the CGI program. + +@menu +* MACs:: +* Constructors:: +* Methods:: +* Functions:: +@end menu + +@node MACs, Constructors, The Query_String class, The Query_String class +@subsection MACs + +@node Constructors +@subsection Constructors + +@deftp {Constructor} Query_String () + +The null constructor, only useful if you are intending to build up a +new query string for eventual inclusion into some part of a HTML page. +@end deftp + +@deftp {Constructor} Query_String (const char *const *const @var{env}) + +The real workhorse constructor. The argument @var{env} should be the +environment variable passed to the CGI's main routine as the third +argument. This will create an object which represents the information +passed to the CGI program via the query string, whether it were sent +via the GET or the PUT protocols. The object returned can +subsequently be used to interrogate the user's request string. +@end deftp + +@node Methods +@subsection Methods + +@deftp {Method} void Query_String::add (const std::string &@var{name}, const T &@var{value}) + +This method will add an entry into the Query_String with key +@var{name} and value a string representation of @var{value}. The type +T of @var{value} may be anything that can be passed into a +std::ostream object via the << operator. +@end deftp + +@deftp {Method} void Query_String::add (const std::string &@var{name}, const Query_String &@var{input}, const T &@var{fallback}) + +This method will add an entry into the current Query_String which is a +copy of the entry in the @var{input} Query_String, unless such entry +does not exist in which case a key @var{name} with value a std::string +representation of @var{fallback} will be added to the current +Query_String. The type T of @var{fallback} may be anything that can +be passed to the << operator of a std::ostream object. +@end deftp + +@deftp {Method} bool Query_String::posted () const + +Returns TRUE if the query string had been sent to the CGI program via +the POST protocol, FALSE otherwise (which case would presumably have +been caused by use of the GET protocol). +@end deftp + +@deftp {Method} T Query_String::get (const std::string &name, const T &fallback) const + +This gets the value associated with the key @var{name} from the query +string, unless no such key was present in which case @var{fallback} is +returned. Note that the type of value returned is the same as that of +@var{fallback}, thus @var{fallback} serves the dual role of defining +the fallback value and determining the return type of the function. +@end deftp + +@deftp {Method} std::vector Query_String::get_list (const std::string &name) const + +In the case that a query string value corresponds to a multiple choice +selection on the HTML form, it will be a comma-separated string of +selected values. This function will return a vector comprised of +these values, interpreted as integers. If there is no key @var{name} +in the query string, then the returned vector will have no elements +(zero length). +@end deftp + +@deftp {Method} std::vector Query_String::get_checked_array (const std::string &NAME) const + +@end deftp + +@deftp {Method} bool Query_String::has (const std::string &NAME) const + +This method returns TRUE if the @var{name} was a variable present in +the query string, FALSE otherwise. +@end deftp + +@deftp {Method} bool Query_String::mac_verified () const + +This method will return TRUE only if there was a MAC present in the +query string, and the MAC was valid. Otherwise FALSE will be +returned. +@end deftp + +@node Functions +@subsection Functions + +@deftypefun static string Query_String::add_mac (string @var{input}) + +This static class member will add a cryptographic MAC onto any string, +but this is only meaningful for composed query strings. +@end deftypefun + + +@node The Hyper_Tags class +@section The Hyper_Tags class +Whereas a HTML document contains markup tags expressed as labels between +angle brackets (possibly in pairs), so a micro-server template file +contains dynamic content holders expressed as labels between square +brackets. The Hyper_Tags class contains methods for replacing single +tags with some dynamically-generated content, and for selectively +keeping or removing sections of the template bracketed between pairs of +hyper tags. + +A Hyper_Tags object should be considered a container of tag +definitions. The CGI program will typically build up a list of such +definitions in the container, until all the work is done when the +template file is read in from local storage and the Hyper_Tags object +is instructed to make all the changes in one go before sending the +result to the server and hence to the user's browser. + +@menu +* Constructors_:: +* Methods_:: +* Functions_:: +@end menu + +@node Constructors_, , The Hyper_Tags class, The Hyper_Tags class +@subsection Constructors_ +@deftp {Constructor} Hyper_Tags () + +The class only has the one, default, constructor, which returns an +empty object waiting to be filled with tag definitions. +@end deftp + +@node Methods_, , Constructors_, The Hyper_Tags class +@subsection Methods_ +@deftp {Method} void Hyper_Tags::harden_last () + +Normally, a later tag definition would overrule any earlier ones when +substitutions are finally made into a template file. However, if it +is desired that the last tag added should be the final tag definition +on substitution, then it can be `hardened' by calling this method. +@end deftp + +@deftp {Method} bool Hyper_Tags::has (const std::string &@var{name}) const + +This method returns TRUE if a tag with the given @var{name} has been +registered with the Hyper_Tags object. In all other cases it returns FALSE. +@end deftp + +@deftp {Method} Hyper_Tags &Hyper_Tags::add (const Hyper_Tags &@var{registry}, const int @var{harden} = 0) + +This method copies all the tag definitions contained in @var{registry} +into the current object, and returns a reference to the current +object. If the optional @var{harden} argument is passed a non-zero +value, then all the incumbent tag definitions will be hardened, as per +the discussion of the harden_last () method above. +@end deftp + +@deftp {Method} Hyper_Tags &Hyper_Tags::add (const std::string &@var{name}, string @var{substitution_text}) + +One of the main methods of the class. Declares that, in the final +substitutions, any parts of the template file which look like +``[@var{name}/]'' should be replaced with @var{substitution_text}. + +The return is a reference to the current object. +@end deftp + +@deftp {Method} Hyper_Tags &Hyper_Tags::add (const std::string &@var{name}, const int value) + +Declares that tags called @var{name} in the template file be replaced +with a string representing the integer @var{value}. The return is a +reference to the current object. +@end deftp + +@deftp {Method} Hyper_Tags &Hyper_Tags::add (const std::string &@var{name}, const double @var{value}, const int @var{precision} = 4) + +Declares that tags called @var{name} be replaced with a string +representing the floating-point @var{value}, with at least +@var{precision} significant figures. The return is a reference to the +current object. +@end deftp + +@deftp {Method} Hyper_Tags &add (const std::string &@var{name}, Query_String &@var{q_s}, const T &@var{fallback}) + +Declares that tags called @var{name} be replaced with a value from +@var{q_s} with the same name if this exists, or with @var{fallback} +otherwise. The type T of fallback should be one of std::string, int, +or double. The return is a reference to the current object. +@end deftp + +@deftp {Method} void add_int_list (const std::string &@var{name}, I @var{begin}, I @var{end}) + +Here, I is an iterator type over an STL container of int's. This +method declares that tags named @var{name} be substituted with a +comma-separated list of integer values. +@end deftp + +@deftp {Method} void add_date (const std::string &@var{name}, const time_t &@var{time}, const std::string &@var{format}) + +Specifies that tags named @var{name} be replaced with a string +representing the date indicated by the UNIX @var{time} object. The +conversion takes place according to @var{format}, which is described +in the strftime () libc manual. +@end deftp + +@deftp {Method} void add_file (const std::string &@var{name}, const std::string &@var{file_name}) + +Specifies that tags named @var{name} in the template HTML file be +replaced with the entire contents of the file called @var{file_name} +in the file system. +@end deftp + +@deftp{Method} void add_passthrough_tag (const Query_String &@var{query_string}, ...) + +The trailing arguments are a list of const char *const, terminated +with a NULL pointer. This method specifies that contents of the HTML +template file which look like ``[pass-through/]'' be replaced with a +set of lines which look like ``'' where the @var{names} are taken from the list of +arguments to the function, and the @var{__values__} are taken from the +@var{query_string} variables with the same names. Thus, if the tag in +the template file is contained within ``
'' markup elements, the +current values in the query string will be propagated into any query +string that the new form produces. +@end deftp + +@deftp{Type} enum Hyper_Tags::Section_Keep @{ KEEP_SECTION, LOSE_SECTION @} +@end deftp + +@deftp{Method} Hyper_Tags §ion (const std::string &@var{name}, const Section_Keep &@var{keep}) + +This method declares the action to be taken when a pair of tags like +``[@var{name}]'' and ``[/@var{name}]'' are seen in a template file. +If @var{keep} is KEEP_SECTION, then the tags are simply removed from +the file leaving the contents between the tags intact. If @var{keep} +is LOSE_SECTION then the tags and all the text between them is removed +from the file. +@end deftp + +@deftp{Method} string Hyper_Tags::substitute (string @var{html_template}, int @var{repeat} = 1) + +One of the main methods of the class. This will go through +@var{html_template} and replace any hyper tags which have been +registered with the substitution text that has been declared as the +replacement. If a tag is seen in the @var{html_template} which has +not been registered with the current object, then this tag will remain +intact in the template. + +Additionally, any pairs of tags seen in @var{html_template} which have +been registered as a section will be removed, possibly removing also +all the text between the tags, according to the registered behaviour. +@end deftp + + +@node Functions_, , Methods_, The Hyper_Tags class +@subsection Functions_ + +@deftypefun static string Hyper_Tags::strip_loose_tags (string @var{input}) + +It may happen that, after processing, a HTML template string still +contains some hyper tags which have not been substituted. This static +function will injudiciously remove any such tags, thus eliminating any +ugliness from the page sent back to the user. +@end deftypefun + + +@node The Http_Server class, , The Hyper_Tags class, Reference +@section The Http_Server class + +@menu +* Constructor__:: +* Functions__:: +@end menu + +@node Constructor__, Functions__, The Http_Server class, The Http_Server class +@subsection Constructor__ + +@deftypefun Http_Server::Http_Server (const int @var{socket}, const +std::map @var{methods}) + +Create a HTTP server to listen on the @var{socket}. Processing for +requests will be delegated to the @var{methods}, referenced by the +HTTP-call path name via the @code{map}. When called, the @var{methods} +will be passed a @code{Query_String} object and a socket on which a +response must be sent; methods are provided in the Http_Server namespace +to facilitate with this. + +Please see the example application to see how this is used in practice. +@end deftypefun + + +@node Functions__, , Constructor__, The Http_Server class +@subsection Functions__ + +@deftypefun bool tick (Http_Server &@var{server}, const long @var{wait_us}) + +Cause the @var{server} to act on a single instruction from a web client, +waiting up to @var{wait_us} micro-seconds for such a request to appear. + +The return is usually @code{TRUE}, but may be @code{FALSE} if the +listening socket goes away (this is a mechanism that could be used by a +request processing function to terminate the server frow within). + +In practice this method is called repeatedly, @emph{ad infinitum}. +@end deftypefun + + +@deftypefun void Http_Server::return_html (const int @var{socket}, +const std::string &@var{html}) + +This method sends the @var{html} to the socket, dressed up as a valid +response to a HTTP request for data. +@end deftypefun + + +@deftypefun void Http_Server::return_text (const int @var{socket}, +const std::string &@var{text}) + +This method sends the @var{text} to the socket, dressed up as a valid +response to a HTTP request for data. +@end deftypefun + + +@deftypefun void Http_Server::return_pdf (const int @var{socket}, +const std::string &@var{pdf}) + +This method sends the @var{pdf} to the socket, dressed up as a valid +response to a HTTP request for data. The `string' is actually +understood as a buffer of arbitrary octects here. +@end deftypefun + + +@deftypefun void Http_Server::return_json (const int @var{socket}, +const std::string &@var{json}) + +This method sends the @var{json} to the socket, dressed up as a valid +response to a HTTP request for data. +@end deftypefun + + +@deftypefun void Http_Server::return_bad (const int @var{socket}) + +This method sends an empty payload to the socket, dressed up as a +@emph{valid} response to a HTTP request for data (it would generally be +taken by an Ecmascript application to be a `bad' response to a request +for data). +@end deftypefun + + +@deftypefun void Http_Server::return_png (const int @var{socket}, +const std::string &@var{png}) + +This method sends the @var{png} to the socket, dressed up as a valid +response to a HTTP request for data. The `string' is actually +understood as a buffer of arbitrary octects here. +@end deftypefun + + +@deftypefun void Http_Server::return_svg (const int @var{socket}, +const std::string &@var{svg}) + +This method sends the @var{svg} to the socket, dressed up as a valid +response to a HTTP request for data. The `string' is actually +understood as a buffer of arbitrary octects here. +@end deftypefun + + +@node Examples of Use, Hints on how the library might be used in a real application, Reference, Top +@chapter Examples of Use +We don't start with the tradition hello, world program as this would +not demonstrate in any way the dynamic nature of CGI programming! The +simplest example we can think of allows the user to input two numbers +and returns the product of them, and the full code for this is +provided in the next section. + +@menu +* Simple example -- Online multiplier:: A simple application of the library +@end menu + +@node Simple example -- Online multiplier +@section Simple example -- Online multiplier + +The following is provided as the simplest code to demonstrate use of the +dmbcs-micro-server library, not to inform of any coding style or quality +system approach. We assume a standard GNU system with recent +@code{make}, @code{bash}, @code{gcc}, etc. + +Start with the HTML file @code{calc.html} + +@verbatim + + Multiplier +

Multiplier

+ + x + = [result/] +
+ CALCULATE + + + +@end verbatim + +And the C++ source file @code{calc.cc} + +@verbatim + #include + + using namespace DMBCS::Micro_Server; + + + /* This function both serves up the basic HTML page, and + * performs the multiplication and injects the result into the + * HTML. */ + void home_page (Query_String const &query, int const socket) + { + auto tags = Hyper_Tags {}; + + add (tags, + "result", + query.get ("arg_1", 0) * query.get ("arg_2", 0)); + + Http_Server::return_html (substitute (tags, + slurp_file ("calc.html"))); + } + + + int main () + { + auto server = Http_Server {2022, + { {"", home_page}, + {"compute", home_page} }}; + + for (;;) tick (server, 1000000); + + return 0; + } +@end verbatim + +then the @code{makefile} + +@verbatim + CXXFLAGS = `pkg-config --cflags dmbcs-micro-server` + LDFLAGS = `pkg-config --libs dmbcs-micro-server` +@end verbatim + +Then at the command line type + +@verbatim + make calc + ./calc +@end verbatim + +then point a browser at @code{http://localhost:2022/} and use the simple +calculator (don't try to do anything funny: the code has been kept +deliberately simple and doesn't do any error checking). Note that an +answer can be obtained directly with a URL like +@code{http://localhost:2022/compute?arg_1=3&arg_2=4}. + + +@node Hints on how the library might be used in a real application, , Examples of Use, Top +@chapter Hints on how the library might be used in a real application +While the basic library as it is serves perfectly well for small CGI +programs, the library was derived from a larger project. From this +experience, it is seen that many large projects will want to produce +specializations of the classes and utility functions provided by the +library for the particular project. The following are some specific +details about how the library was enhanced in the original project. + +@menu +* Web-site skins:: Web sites which provide a user-selected `look-and-feel' +* Other inheritence:: Other ideas +@end menu + +@node Web-site skins, Other inheritence, Hints on how the library might be used in a real application, Hints on how the library might be used in a real application +@section Web-site skins +The underlying paradigm promoted by the library is one where the +programmer supplies template HTML files which the CGI program +populates with extra dynamic content. This opens the possibility of +supplying the same dynamic content into different templates, for +example where a web site allows the user to choose a favorite `skin', +or `look-and-feel', then each template file would exist in different +forms to provide all the different skins available. In this case, the +library can be extended by ensuring that whenever a template is +slurped from local storage for use, it is the template appropriate for +the user's choice of skin that is pulled up. + +In the original project, this was achieved by placing all templates +for a skin into a single directory to which the CGI program has access +(it was actually a sub-directory underneath the cgi-bin directory, and +the web server was configured to *not* allow direct access from a +browser to these files). + +The main modification was to add a new utility function in the +project's namespace + +@code{string slurp_file (const std::string &skin, +const std::string &filename)} + +which is called by the program in lieu of slurp_file, and +ensures that the file from the correct skin directory is chosen, +calling through to the library function to get the eventual work +done. To complete the effect, it is also necessary to derive a new +class from Hyper_Tags with the following additional methods + +@code{blah, blah, blah} + +(The Query_String class works completely as is; it may be +convenient to introduce this into the projects own namespace with a + +@code{typedef Query_String Query_String;} + +line in a project header file.) + +@node Other inheritence, , Web-site skins, Hints on how the library might be used in a real application +@section Other inheritence + +@bye diff --git a/makefile.am b/makefile.am new file mode 100644 index 0000000..4b869e2 --- /dev/null +++ b/makefile.am @@ -0,0 +1,36 @@ +# dmbcs-micro-server A C++ library providing CGI or built-in +# web server functions +# +# Copyright (C) 2018 DM Bespoke Computer Solutions Ltd +# +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or (at +# your option) any later version. +# +# This program is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with this program. If not, see . + + + +SUBDIRS = DMBCS/micro-server + +ACLOCAL_AMFLAGS = -I m4 + +pkgconfigdir = ${prefix}/lib/pkgconfig + +pkgconfig_DATA = dmbcs-micro-server.pc + +AM_MAKEINFOHTMLFLAGS = --no-split --css-ref=dmbcs-info.css + +info_TEXINFOS = dmbcs-micro-server.texi + +MAINTAINERCLEANFILES = aclocal.m4 compile config.guess config.sub configure \ + dmbcs-micro-server.html \ + depcomp install-sh ltmain.sh makefile.in \ + missing texinfo.tex mdate-sh