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

   1 /*
   2  * Usage: as CGI script
   3  */
   4 /*
   5  * Copyright (C) 1998-1999,2003 Ian Jackson
   6  *
   7  * This is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with userv-utils; if not, write to the Free Software
  19  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  20  *
  21  * $Id$
  22  */
  23
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <ctype.h>
  27 #include <unistd.h>
  28 #include <sys/types.h>
  29 #include <sys/wait.h>
  30
  31 #include "ucgi.h"
  32
  33 static const char *const default_envok[] = {
  34   "AUTH_TYPE",
  35   "CONTENT_TYPE",
  36   "CONTENT_LENGTH",
  37   "DOCUMENT_ROOT",
  38   "GATEWAY_INTERFACE",
  39   "HTTP_*",
  40   "HTTPS",
  41   "PATH_INFO",
  42   "PATH_TRANSLATED",
  43   "QUERY_STRING",
  44   "REDIRECT_*",
  45   "REMOTE_*",
  46   "REQUEST_METHOD",
  47   "REQUEST_URI",
  48   "SCRIPT_*",
  49   "SERVER_*",
  50   "SSL_*",
  51   0
  52 };
  53
  54 struct buildargs {
  55   const char **v;
  56   int n, max;
  57 };
  58
  59 static void addarg(struct buildargs *args, const char *a) {
  60   if (args->n > args->max) error("too many arguments", 500);
  61   args->v[args->n++]= a;
  62 }
  63
  64 static void add_userv_var(const char *fulln,
  65                           const char *en, const char *ev, void *p) {
  66   struct buildargs *args= p;
  67   size_t l;
  68   char *a;
  69
  70   l= strlen(ev);
  71   if (l > MAX_ENVVAR_VALUE) error("environment variable too long", 500);
  72   a= xmalloc(strlen(en)+l+6);
  73   sprintf(a,"-DE_%s=%s",en,ev);
  74   addarg(args, a);
  75 }
  76
  77 int main(int argc, const char **argv) {
  78   char *username;
  79   const char *slash2, *pathi, *ev, *av;
  80   const char *const *envok = 0;
  81   size_t usernamelen, l;
  82   struct buildargs args;
  83   pid_t child, rchild;
  84   int status;
  85
  86   l= strlen(argv[0]);
  87   if (l>6 && !strcmp(argv[0]+l-6,"-debug")) debugmode= 1;
  88
  89   if (debugmode) {
  90     if (fputs("Content-Type: text/plain\n\n",stdout)==EOF || fflush(stdout))
  91       syserror("write stdout");
  92     if (dup2(1,2)<0) { perror("dup stdout to stderr"); exit(-1); }
  93     D( printf(";;; UCGI\n"); )
  94   }
  95
  96   if (argc > MAX_ARGS) error("too many arguments", 500);
  97
  98   ev= getenv("UCGI_ENV_FILTER");
  99   if (ev)
 100     envok= load_filters(LOADF_MUST, ev, LF_END);
 101   else
 102     envok= load_filters(0, "/etc/userv/ucgi.env-filter", LF_END);
 103
 104   pathi= getenv("PATH_INFO");
 105   if (!pathi) error("PATH_INFO not found", 500);
 106   D( if (debugmode) {
 107        printf(";; find user name...\n"
 108               ";;   initial PATH_INFO = `%s'\n",
 109               pathi);
 110   } )
 111   if (pathi[0] != '/' || pathi[1] != '~')
 112     error("PATH_INFO must start with /~", 400);
 113   slash2= strchr(pathi+2,'/');
 114   if (!slash2) error("PATH_INFO must have more than one /", 400);
 115   usernamelen= slash2-(pathi+2);
 116   if (usernamelen > MAX_USERNAME_LEN) error("PATH_INFO username too long", 400);
 117   username= xmalloc(usernamelen+1);
 118   memcpy(username,pathi+2,usernamelen); username[usernamelen]= 0;
 119   D( if (debugmode)
 120        printf(";;   user = `%s'; tail = `%s'\n", username, slash2); )
 121   if (!isalpha(username[0]))
 122     error("username 1st character is not alphabetic", 400);
 123   xsetenv("PATH_INFO",slash2,1);
 124
 125   args.n= 0; args.max= argc + MAX_ENVVARS + 10;
 126   args.v= xmalloc(args.max * sizeof(*args.v));
 127
 128   addarg(&args, "userv");
 129   if (debugmode) addarg(&args, "-DDEBUG=1");
 130
 131   filter_environment(FILTF_WILDCARD, "", envok, default_envok,
 132                      add_userv_var, &args);
 133
 134   addarg(&args, username);
 135   addarg(&args, "www-cgi");
 136   while ((av= (*++argv))) addarg(&args, av);
 137   addarg(&args, 0);
 138
 139   if (debugmode) {
 140     D( fflush(stdout); )
 141     child= fork(); if (child==-1) syserror("fork");
 142     if (child) {
 143       rchild= waitpid(child,&status,0);
 144       if (rchild==-1) syserror("waitpid");
 145       printf("\nexit status %d %d\n",(status>>8)&0x0ff,status&0x0ff);
 146       exit(0);
 147     }
 148   }
 149
 150   D( if (debugmode) {
 151        int i;
 152
 153        printf(";; final command line...\n");
 154        for (i = 0; args.v[i]; i++)
 155          printf(";;   %s\n", args.v[i]);
 156        fflush(stdout);
 157   } )
 158
 159   execvp("userv",(char*const*)args.v);
 160   syserror("exec userv");
 161   return -1;
 162 }