mdw@git.distorted.org.uk Git - userv-utils/blob - www-cgi/ucgitarget.c

   1 /*
   2  * Usage: as CGI script, but called by userv
   3  * environment variables are USERV_U_E_...
   4  */
   5 /*
   6  * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
   7  * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
   8  * Copyright 1999,2003
   9  *    Chancellor Masters and Scholars of the University of Cambridge
  10  * Copyright 2010 Tony Finch <fanf@dotat.at>
  11  *
  12  * This is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 3 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  20  * General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with userv-utils; if not, see http://www.gnu.org/licenses/.
  24  */
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29 #include <getopt.h>
  30 #include <unistd.h>
  31 #include <sys/types.h>
  32 #include <sys/wait.h>
  33 #include <sys/stat.h>
  34
  35 #include "ucgi.h"
  36
  37 static const char *const default_envok[]= {
  38   "AUTH_TYPE",
  39   "CONTENT_LENGTH",
  40   "CONTENT_TYPE",
  41   "DOCUMENT_ROOT",
  42   "GATEWAY_INTERFACE",
  43   "HTTP_ACCEPT",
  44   "HTTP_ACCEPT_CHARSET",
  45   "HTTP_ACCEPT_ENCODING",
  46   "HTTP_ACCEPT_LANGUAGE",
  47   "HTTP_CACHE_CONTROL",
  48   "HTTP_CONNECTION",
  49   "HTTP_CONTENT_ENCODING",
  50   "HTTP_COOKIE",
  51   "HTTP_DNT",
  52   "HTTP_HOST",
  53   "HTTP_KEEP_ALIVE",
  54   "HTTP_NEGOTIATE",
  55   "HTTP_PRAGMA",
  56   "HTTP_REFERER",
  57   "HTTP_USER_AGENT",
  58   "HTTP_VIA",
  59   "HTTP_X_FORWARDED_FOR",
  60   "HTTPS",
  61   "PATH_INFO",
  62   "PATH_TRANSLATED",
  63   "QUERY_STRING",
  64   "REDIRECT_HANDLER",
  65   "REDIRECT_SCRIPT_URI",
  66   "REDIRECT_SCRIPT_URL",
  67   "REDIRECT_STATUS",
  68   "REDIRECT_URL",
  69   "REMOTE_ADDR",
  70   "REMOTE_HOST",
  71   "REMOTE_USER",
  72   "REMOTE_IDENT",
  73   "REQUEST_METHOD",
  74   "REQUEST_URI",
  75   "SCRIPT_FILENAME",
  76   "SCRIPT_NAME",
  77   "SCRIPT_URI",
  78   "SCRIPT_URL",
  79   "SERVER_ADDR",
  80   "SERVER_ADMIN",
  81   "SERVER_NAME",
  82   "SERVER_PORT",
  83   "SERVER_PROTOCOL",
  84   "SERVER_SIGNATURE",
  85   "SERVER_SOFTWARE",
  86   "SSL_CIPHER",
  87   "SSL_CLIENT_S_DN",
  88   "SSL_CLIENT_VERIFY",
  89   "SSL_PROTOCOL",
  90   0
  91 };
  92
  93 static void setenvar(const char *fulln,
  94                      const char *en, const char *ep, void *p) {
  95   xsetenv(en, ep, 1);
  96   unsetenv(fulln);
  97 }
  98
  99 int main(int argc, char **argv) {
 100   char *scriptpath, *newvar;
 101   const char *nextslash, *lastslash, *pathi, *ev, *ev2, *scriptdir, *av;
 102   const char *const *envok;
 103   const char **arguments;
 104   size_t scriptdirlen, scriptpathlen, l;
 105   struct stat stab;
 106   int i, r, nargs;
 107   const char *filters= 0;
 108
 109   ev= getenv("USERV_U_DEBUG");
 110   if (ev && *ev) debugmode= 1;
 111
 112   D( if (debugmode) printf(";;; UCGITARGET\n"); )
 113   if (argc > MAX_ARGS) error("too many arguments", 500);
 114
 115   for (;;) {
 116     i= getopt(argc, argv, "+e:"); if (i < 0) break;
 117     switch (i) {
 118     case 'e': filters= optarg; break;
 119     default: error("bad command line", 500); break;
 120     }
 121   }
 122   argc -= optind; argv += optind;
 123
 124   if (!*argv) error("no script directory argument", 500);
 125   ev= getenv("HOME"); if (!ev) error("no HOME env. var", 500);
 126   l= strlen(*argv)+strlen(ev);
 127   newvar= xmalloc(l+2);
 128   sprintf(newvar,"%s/%s",ev,*argv);
 129   scriptdir= newvar;
 130   scriptdirlen= strlen(scriptdir);
 131
 132   if (filters)
 133     envok= load_filters(LOADF_MUST, filters, LF_END);
 134   else {
 135     envok= load_filters(0,
 136                         ".userv/ucgitarget.env-filter",
 137                         "/etc/userv/ucgitarget.env-filter",
 138                         LF_END);
 139   }
 140
 141   filter_environment(0, "USERV_U_E_", envok, default_envok, setenvar, 0);
 142
 143   scriptpath= 0;
 144   pathi= getenv("PATH_INFO");
 145   if (!pathi) error("PATH_INFO not found", 500);
 146   lastslash= pathi;
 147   D( if (debugmode) {
 148        printf(";; find script name...\n"
 149               ";;   PATH_INFO = `%s'\n",
 150               pathi);
 151   } )
 152   for (;;) {
 153     if (*lastslash != '/') error("PATH_INFO expected slash not found", 400);
 154     if (lastslash[1]=='.' || lastslash[1]=='#' || !lastslash[1])
 155       error("bad char begin", 400);
 156     nextslash= strchr(lastslash+1,'/');
 157     if (!nextslash) nextslash= lastslash+1+strlen(lastslash+1);
 158     if (!nextslash) error("insufficient elements in PATH_INFO", 400);
 159     if (nextslash==lastslash+1) error("empty component in PATH_INFO", 400);
 160     if (nextslash-pathi > MAX_SCRIPTPATH_LEN)
 161       error("PATH_INFO script path too long", 400);
 162     scriptpathlen= scriptdirlen+(nextslash-pathi);
 163     scriptpath= xrealloc(scriptpath,scriptpathlen+1);
 164     strcpy(scriptpath,scriptdir);
 165     memcpy(scriptpath+scriptdirlen,pathi,nextslash-pathi);
 166     scriptpath[scriptpathlen]= 0;
 167     if (scriptpath[scriptpathlen-1]=='~') error("bad char end", 400);
 168     D( if (debugmode) printf(";;   try `%s'\n", scriptpath); )
 169     r= stat(scriptpath,&stab); if (r) syserror("stat script");
 170     if (S_ISREG(stab.st_mode)) break;
 171     if (!S_ISDIR(stab.st_mode)) error("script not directory or file", 500);
 172     lastslash= nextslash;
 173   }
 174   D( if (debugmode) printf(";;   found script: tail = `%s'\n", nextslash); )
 175   if (*nextslash) xsetenv("PATH_INFO",nextslash,1);
 176   else unsetenv("PATH_INFO");
 177
 178   newvar= xmalloc(scriptpathlen+strlen(nextslash)+3);
 179   sprintf(newvar,"%s%s",scriptpath,nextslash);
 180   xsetenv("PATH_TRANSLATED",newvar,1);
 181
 182   xsetenv("SCRIPT_FILENAME",scriptpath,1);
 183
 184   ev= getenv("SCRIPT_NAME");
 185   if (ev) {
 186     ev2= getenv("USER"); if (!ev2) error("no USER variable", 500);
 187     newvar= xmalloc(strlen(ev)+2+strlen(ev2)+scriptpathlen-scriptdirlen+2);
 188     sprintf(newvar,"%s/~%s%s",ev,ev2,scriptpath+scriptdirlen);
 189     xsetenv("SCRIPT_NAME",newvar,1);
 190   }
 191
 192   arguments= xmalloc(sizeof(const char*)*(argc+5));
 193   nargs= 0;
 194
 195   arguments[nargs++]= scriptpath;
 196   while ((av= (*++argv))) arguments[nargs++]= av;
 197   arguments[nargs++]= 0;
 198
 199   D( if (debugmode) {
 200        int i;
 201
 202        printf(";; final environment...\n");
 203        for (i = 0; environ[i]; i++)
 204          printf(";;   %s\n", environ[i]);
 205
 206        printf(";; final command line...\n");
 207        for (i = 0; arguments[i]; i++)
 208          printf(";;   %s\n", arguments[i]);
 209        fflush(stdout);
 210   } )
 211
 212   execvp(scriptpath,(char*const*)arguments);
 213   syserror("exec script");
 214   return -1;
 215 }