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 <unistd.h>
  30 #include <sys/types.h>
  31 #include <sys/wait.h>
  32 #include <sys/stat.h>
  33
  34 #include "ucgi.h"
  35
  36 static void *xrealloc(void *ptr, size_t sz) {
  37   void *r;
  38
  39   r= realloc(ptr,sz);
  40   if (!r) syserror("realloc failed");
  41   return r;
  42 }
  43
  44 int main(int argc, const char **argv) {
  45   char *uservarn, *scriptpath, *newvar;
  46   const char *nextslash, *lastslash, *pathi, *ev, *ev2, *en, *scriptdir, *av;
  47   const char *const *ep;
  48   const char **arguments;
  49   size_t scriptdirlen, scriptpathlen, l, uservarnl;
  50   struct stat stab;
  51   int r, nargs;
  52
  53   ev= getenv("USERV_U_DEBUG");
  54   if (ev && *ev) debugmode= 1;
  55
  56   if (argc > MAX_ARGS) error("too many arguments");
  57
  58   if (!*++argv) error("no script directory argument");
  59   ev= getenv("HOME"); if (!ev) error("no HOME env. var");
  60   l= strlen(*argv)+strlen(ev);
  61   newvar= xmalloc(l+2);
  62   sprintf(newvar,"%s/%s",ev,*argv);
  63   scriptdir= newvar;
  64   scriptdirlen= strlen(scriptdir);
  65
  66   uservarn= 0;
  67   uservarnl= 0;
  68   for (ep= envok; (en= *ep); ep++) {
  69     l= strlen(en)+11;
  70     if (uservarnl<l) { uservarn= xrealloc(uservarn,l); uservarnl= l; }
  71     sprintf(uservarn,"USERV_U_E_%s",en);
  72     ev= getenv(uservarn); if (!ev) continue;
  73     if (strlen(ev) > MAX_ENVVAR_VALUE) error("environment variable too long");
  74     if (setenv(en,ev,1)) syserror("setenv");
  75     unsetenv(uservarn);
  76   }
  77
  78   scriptpath= 0;
  79   pathi= getenv("PATH_INFO");
  80   if (!pathi) error("PATH_INFO not found");
  81   lastslash= pathi;
  82   for (;;) {
  83     if (*lastslash != '/') error("PATH_INFO expected slash not found");
  84     if (lastslash[1]=='.' || lastslash[1]=='#' || !lastslash[1]) error("bad char begin");
  85     nextslash= strchr(lastslash+1,'/');
  86     if (!nextslash) nextslash= lastslash+1+strlen(lastslash+1);
  87     if (!nextslash) error("insufficient elements in PATH_INFO");
  88     if (nextslash==lastslash+1) error("empty component in PATH_INFO");
  89     if (nextslash-pathi > MAX_SCRIPTPATH_LEN) error("PATH_INFO script path too long");
  90     scriptpathlen= scriptdirlen+(nextslash-pathi);
  91     scriptpath= xrealloc(scriptpath,scriptpathlen+1);
  92     strcpy(scriptpath,scriptdir);
  93     memcpy(scriptpath+scriptdirlen,pathi,nextslash-pathi);
  94     scriptpath[scriptpathlen]= 0;
  95     if (scriptpath[scriptpathlen-1]=='~') error("bad char end");
  96     r= stat(scriptpath,&stab); if (r) syserror("stat script");
  97     if (S_ISREG(stab.st_mode)) break;
  98     if (!S_ISDIR(stab.st_mode)) syserror("script not directory or file");
  99     lastslash= nextslash;
 100   }
 101   if (*nextslash) xsetenv("PATH_INFO",nextslash,1);
 102   else unsetenv("PATH_INFO");
 103
 104   newvar= xmalloc(scriptpathlen+strlen(nextslash)+3);
 105   sprintf(newvar,"%s%s",scriptpath,nextslash);
 106   xsetenv("PATH_TRANSLATED",newvar,1);
 107
 108   xsetenv("SCRIPT_FILENAME",scriptpath,1);
 109
 110   ev= getenv("SCRIPT_NAME");
 111   if (ev) {
 112     ev2= getenv("USER"); if (!ev2) error("no USER variable");
 113     newvar= xmalloc(strlen(ev)+2+strlen(ev2)+scriptpathlen-scriptdirlen+2);
 114     sprintf(newvar,"%s/~%s%s",ev,ev2,scriptpath+scriptdirlen);
 115     xsetenv("SCRIPT_NAME",newvar,1);
 116   }
 117
 118   arguments= xmalloc(sizeof(const char*)*(argc+5));
 119   nargs= 0;
 120
 121   arguments[nargs++]= scriptpath;
 122   while ((av= (*++argv))) arguments[nargs++]= av;
 123   arguments[nargs++]= 0;
 124
 125   execvp(scriptpath,(char*const*)arguments);
 126   syserror("exec script");
 127   return -1;
 128 }