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

   1 /*
   2  * Usage: as CGI script
   3  */
   4 /*
   5  * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
   7  * Copyright 1999,2003
   8  *    Chancellor Masters and Scholars of the University of Cambridge
   9  * Copyright 2010 Tony Finch <fanf@dotat.at>
  10  *
  11  * This is free software; you can redistribute it and/or modify it
  12  * under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 3 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful, but
  17  * WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with userv-utils; if not, see http://www.gnu.org/licenses/.
  23  */
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <unistd.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31
  32 #include "ucgi.h"
  33
  34 int main(int argc, const char **argv) {
  35   char *defarg, *username;
  36   const char *slash2, *pathi, *ev, *en, *av;
  37   const char *const *ep;
  38   const char **arguments;
  39   size_t usernamelen, l;
  40   pid_t child, rchild;
  41   int nargs, status;
  42
  43   l= strlen(argv[0]);
  44   if (l>6 && !strcmp(argv[0]+l-6,"-debug")) debugmode= 1;
  45
  46   if (debugmode) {
  47     if (fputs("Content-Type: text/plain\n\n",stdout)==EOF || fflush(stdout))
  48       syserror("write stdout");
  49     if (dup2(1,2)<0) { perror("dup stdout to stderr"); exit(-1); }
  50   }
  51
  52   if (argc > MAX_ARGS) error("too many arguments");
  53
  54   pathi= getenv("PATH_INFO");
  55   if (!pathi) error("PATH_INFO not found");
  56   if (pathi[0] != '/' || pathi[1] != '~') error("PATH_INFO must start with /~");
  57   slash2= strchr(pathi+2,'/'); if (!slash2) error("PATH_INFO must have more than one /");
  58   usernamelen= slash2-(pathi+2);
  59   if (usernamelen > MAX_USERNAME_LEN) error("PATH_INFO username too long");
  60   username= xmalloc(usernamelen+1);
  61   memcpy(username,pathi+2,usernamelen); username[usernamelen]= 0;
  62   if (!isalpha(username[0])) error("username 1st character is not alphabetic");
  63   xsetenv("PATH_INFO",slash2,1);
  64
  65   arguments= xmalloc(sizeof(const char*)*(nenvok+argc+10));
  66   nargs= 0;
  67
  68   arguments[nargs++]= "userv";
  69   if (debugmode) arguments[nargs++]= "-DDEBUG=1";
  70
  71   for (ep= envok; (en= *ep); ep++) {
  72     ev= getenv(en); if (!ev) continue;
  73     l= strlen(ev); if (l > MAX_ENVVAR_VALUE) error("environment variable too long");
  74     defarg= xmalloc(strlen(en)+l+6);
  75     sprintf(defarg,"-DE_%s=%s",en,ev);
  76     arguments[nargs++]= defarg;
  77   }
  78
  79   arguments[nargs++]= username;
  80   arguments[nargs++]= "www-cgi";
  81   while ((av= (*++argv))) arguments[nargs++]= av;
  82   arguments[nargs++]= 0;
  83
  84   if (debugmode) {
  85     child= fork(); if (child==-1) syserror("fork");
  86     if (child) {
  87       rchild= waitpid(child,&status,0);
  88       if (rchild==-1) syserror("waitpid");
  89       printf("\nexit status %d %d\n",(status>>8)&0x0ff,status&0x0ff);
  90       exit(0);
  91     }
  92   }
  93
  94   execvp("userv",(char*const*)arguments);
  95   syserror("exec userv");
  96   return -1;
  97 }