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

   1 /*
   2  * Copyright (C) 1998-1999,2003 Ian Jackson
   3  *
   4  * This is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with userv-utils; if not, write to the Free Software
  16  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  *
  18  * $Id$
  19  */
  20
  21 #include <assert.h>
  22 #include <ctype.h>
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <errno.h>
  27
  28 #include <unistd.h>
  29
  30 #include "ucgi.h"
  31
  32 int debugmode= 0;
  33
  34 static void outerror(void) {
  35   perror("stdout");
  36   exit(debugmode ? 0 : -1);
  37 }
  38
  39 void syserror(const char *m) {
  40   if (printf("Content-Type: text/plain\n"
  41              "Status: 500\n\n"
  42              "ucgi: system call error:\n"
  43              "%s: %s\n",
  44              m,strerror(errno))==EOF || fflush(stdout)) outerror();
  45   exit(0);
  46 }
  47
  48 void error(const char *m, int st) {
  49   if (printf("Content-Type: text/plain\n"
  50              "Status: %d\n\n"
  51              "ucgi: error:\n"
  52              "%s\n",
  53              st, m)==EOF || fflush(stdout)) outerror();
  54   exit(0);
  55 }
  56
  57 void *xmalloc(size_t sz) {
  58   void *r;
  59
  60   r= malloc(sz);
  61   if (!r) syserror("malloc failed");
  62   return r;
  63 }
  64
  65 void *xrealloc(void *ptr, size_t sz) {
  66   void *r;
  67
  68   r= realloc(ptr,sz);
  69   if (!r) syserror("realloc failed");
  70   return r;
  71 }
  72
  73 void xsetenv(const char *en, const char *ev, int overwrite) {
  74   if (setenv(en,ev,overwrite)) syserror("setenv");
  75 }
  76
  77 const char **load_filters(unsigned flags, const char *first, ...) {
  78   va_list ap;
  79   const char *name, *p, *q, **v;
  80   char *pp;
  81   size_t l, n, sz;
  82   FILE *fp;
  83   char buf[MAX_ENVVAR_NAME];
  84
  85   D( if (debugmode) printf(";; load_filters...\n"); )
  86   va_start(ap, first);
  87   for (name= first; name; name= va_arg(ap, const char *)) {
  88     fp= fopen(name, "r"); if (fp) goto opened;
  89     D( if (debugmode)
  90          printf(";;   file `%s': %s\n", name, strerror(errno)); )
  91     if (errno != ENOENT) syserror("failed to open environment filters");
  92   }
  93   va_end(ap);
  94   if (flags & LOADF_MUST) syserror("failed to open environment filters");
  95   D( if (debugmode) printf(";;   using default filters\n"); )
  96   return 0;
  97
  98 opened:
  99   va_end(ap);
 100   D( if (debugmode) printf(";;   file `%s': OK\n", name); )
 101
 102   n= 0; sz= 128; v= xmalloc(sz * sizeof(*v));
 103   for (;;) {
 104     if (!fgets(buf, sizeof(buf), fp)) break;
 105     l= strlen(buf);
 106     if (buf[l - 1] == '\n') buf[--l]= 0;
 107     if (l + 1 == sizeof(buf))
 108       error("line too long in environment filter file", 500);
 109     p= buf; q= p + l;
 110     while (isspace((unsigned char)*p)) p++;
 111     while (q > p && isspace((unsigned char)q[-1])) q--;
 112     if (*p == '#' || p == q) continue;
 113     l= q - p;
 114     pp= xmalloc(l + 1);
 115     memcpy(pp, p, l);
 116     pp[l]= 0;
 117     v[n++]= pp;
 118     D( if (debugmode) printf(";;   filter: `%s'\n", pp); )
 119     if (n >= sz) {
 120       sz *= 2;
 121       v= xrealloc(v, sz * sizeof(*v));
 122     }
 123   }
 124   if (ferror(fp)) syserror("failed to read environment filters");
 125   fclose(fp);
 126   return v;
 127 }
 128
 129 static int envvar_match(unsigned flags, const char *en,
 130                         const char *const *patv,
 131                         const char *const *defaults,
 132                         const char **ev) {
 133   const char *const *patp;
 134   const char *q, *pat;
 135   int acceptp;
 136   int rc;
 137
 138   if (!patv) { patv= defaults; defaults= 0; }
 139   for (patp= patv; (pat= *patp); patp++) {
 140     q= en;
 141     acceptp= 1;
 142     if (*pat == '!' && (flags & FILTF_WILDCARD)) { acceptp= 0; pat++; }
 143     else if (*pat == '?') {
 144       if (strcmp(pat + 1, "DEFAULTS") == 0) {
 145         assert(defaults);
 146         rc= envvar_match(flags, en, defaults, 0, ev);
 147         if (rc) return rc;
 148       } else
 149         error("unknown pattern directive", 500);
 150       continue;
 151     }
 152
 153     for (;;) {
 154       if (!*pat) {
 155         if (*q != '=') {
 156           D( if (debugmode)
 157                printf(";;     mismatch `%s' (prefix)\n", *patp); )
 158           break;
 159         }
 160         D( if (debugmode) printf(";;     matched pattern `%s'\n", *patp); )
 161         goto match;
 162       } else if (*pat == '*' && (flags & FILTF_WILDCARD)) {
 163         q = strchr(q, '=');
 164         if (!q) {
 165           D( if (debugmode)
 166                printf(";;     mismatch `%s' (discard: no `=')\n", *patp); )
 167           return -1;
 168         }
 169         D( if (debugmode)
 170              printf(";;     wildcard match for `%s'\n", *patp); )
 171         goto match;
 172       } else {
 173         if (*pat++ != *q++) {
 174           D( if (debugmode) printf(";;     mismatch `%s'\n", *patp); )
 175           break;
 176         }
 177       }
 178     }
 179   }
 180   return 0;
 181
 182 match:
 183   if (!acceptp) return -1;
 184   *ev= q + 1;
 185   return +1;
 186 }
 187
 188 void filter_environment(unsigned flags, const char *prefix_in,
 189                         const char *const *patv,
 190                         const char *const *defaults,
 191                         void (*foundone)(const char *fulln,
 192                                          const char *en, const char *ev,
 193                                          void *p),
 194                         void *p) {
 195   char *const *ep;
 196   const char *en, *ev;
 197   char enbuf[MAX_ENVVAR_NAME];
 198   size_t n, pn = strlen(prefix_in);
 199
 200   D( if (debugmode) printf(";; filter_environment...\n"); )
 201   for (ep= environ; (en= *ep); ep++) {
 202     D( if (debugmode) printf(";;   consider env-var `%s'\n", en); )
 203     if (strncmp(en, prefix_in, pn) != 0 || !en[pn]) {
 204       D( if (debugmode) printf(";;     doesn't match prefix\n"); )
 205       continue;
 206     }
 207     if (envvar_match(flags, en + pn, patv, defaults, &ev) > 0) {
 208       n= strcspn(en, "=");
 209       if (n >= sizeof(enbuf))
 210         error("environment variable name too long", 500);
 211       memcpy(enbuf, en, n);
 212       enbuf[n]= 0;
 213       D( if (debugmode)
 214            printf(";;     full = `%s'; tail = `%s'; value = `%s'\n",
 215                   enbuf, enbuf + pn, ev); )
 216       foundone(enbuf, enbuf + pn, ev, p);
 217     }
 218   }
 219 }