dist/ipf/lib/load_http.c

   1 /*      $NetBSD$        */
   2
   3 /*
   4  * Copyright (C) 2006 by Darren Reed.
   5  *
   6  * See the IPFILTER.LICENCE file for details on licencing.
   7  *
   8  * Id: load_http.c,v 1.1.2.2 2009/07/23 20:01:12 darrenr Exp
   9  */
  10
  11 #include "ipf.h"
  12
  13 /*
  14  * Because the URL can be included twice into the buffer, once as the
  15  * full path for the "GET" and once as the "Host:", the buffer it is
  16  * put in needs to be larger than 512*2 to make room for the supporting
  17  * text. Why not just use snprintf and truncate? The warning about the
  18  * URL being too long tells you something is wrong and does not fetch
  19  * any data - just truncating the URL (with snprintf, etc) and sending
  20  * that to the server is allowing an unknown and unintentioned action
  21  * to happen.
  22  */
  23 #define MAX_URL_LEN     512
  24 #define LOAD_BUFSIZE    (MAX_URL_LEN * 2 + 128)
  25
  26 /*
  27  * Format expected is one addres per line, at the start of each line.
  28  */
  29 alist_t *
  30 load_http(char *url)
  31 {
  32         char *s, *t, *u, buffer[LOAD_BUFSIZE], *myurl;
  33         int fd, len, left, port, endhdr, removed;
  34         alist_t *a, *rtop, *rbot;
  35         struct sockaddr_in sin;
  36         struct hostent *host;
  37         size_t rem;
  38
  39         /*
  40          * More than this would just be absurd.
  41          */
  42         if (strlen(url) > MAX_URL_LEN) {
  43                 fprintf(stderr, "load_http has a URL > %d bytes?!\n",
  44                         MAX_URL_LEN);
  45                 return NULL;
  46         }
  47
  48         fd = -1;
  49         rtop = NULL;
  50         rbot = NULL;
  51
  52         myurl = strdup(url);
  53         if (myurl == NULL)
  54                 goto done;
  55
  56         rem = sizeof(buffer);
  57         left = snprintf(buffer, rem, "GET %s HTTP/1.0\r\n", url);
  58         if (left < 0 || left > rem)
  59                 goto done;
  60         rem -= left;
  61
  62         s = myurl + 7;                  /* http:// */
  63         t = strchr(s, '/');
  64         if (t == NULL) {
  65                 fprintf(stderr, "load_http has a malformed URL '%s'\n", url);
  66                 goto done;
  67         }
  68         *t++ = '\0';
  69
  70         /*
  71          * 10 is the length of 'Host: \r\n\r\n' below.
  72          */
  73         if (strlen(s) + strlen(buffer) + 10 > sizeof(buffer)) {
  74                 fprintf(stderr, "load_http has a malformed URL '%s'\n", url);
  75                 free(myurl);
  76                 return NULL;
  77         }
  78
  79         u = strchr(s, '@');
  80         if (u != NULL)
  81                 s = u + 1;              /* AUTH */
  82
  83         left = snprintf(buffer + left, rem, "Host: %s\r\n\r\n", s);
  84         if (left < 0 || left > rem)
  85                 goto done;
  86         rem -= left;
  87
  88         u = strchr(s, ':');
  89         if (u != NULL) {
  90                 *u++ = '\0';
  91                 port = atoi(u);
  92                 if (port < 0 || port > 65535)
  93                         goto done;
  94         } else {
  95                 port = 80;
  96         }
  97
  98         memset(&sin, 0, sizeof(sin));
  99         sin.sin_family = AF_INET;
 100         sin.sin_port = htons(port);
 101
 102         if (isdigit((unsigned char)*s)) {
 103                 if (inet_aton(s, &sin.sin_addr) == -1) {
 104                         goto done;
 105                 }
 106         } else {
 107                 host = gethostbyname(s);
 108                 if (host == NULL)
 109                         goto done;
 110                 memcpy(&sin.sin_addr, host->h_addr_list[0],
 111                        sizeof(sin.sin_addr));
 112         }
 113
 114         fd = socket(AF_INET, SOCK_STREAM, 0);
 115         if (fd == -1)
 116                 goto done;
 117
 118         if (connect(fd, (struct sockaddr *)&sin, sizeof(sin)) == -1)
 119                 goto done;
 120
 121         len = strlen(buffer);
 122         if (write(fd, buffer, len) != len)
 123                 goto done;
 124
 125         s = buffer;
 126         endhdr = 0;
 127         left = sizeof(buffer) - 1;
 128
 129         while ((len = read(fd, s, left)) > 0) {
 130                 s[len] = '\0';
 131                 left -= len;
 132                 s += len;
 133
 134                 if (endhdr >= 0) {
 135                         if (endhdr == 0) {
 136                                 t = strchr(buffer, ' ');
 137                                 if (t == NULL)
 138                                         continue;
 139                                 t++;
 140                                 if (*t != '2')
 141                                         break;
 142                         }
 143
 144                         u = buffer;
 145                         while ((t = strchr(u, '\r')) != NULL) {
 146                                 if (t == u) {
 147                                         if (*(t + 1) == '\n') {
 148                                                 u = t + 2;
 149                                                 endhdr = -1;
 150                                                 break;
 151                                         } else
 152                                                 t++;
 153                                 } else if (*(t + 1) == '\n') {
 154                                         endhdr++;
 155                                         u = t + 2;
 156                                 } else
 157                                         u = t + 1;
 158                         }
 159                         if (endhdr >= 0)
 160                                 continue;
 161                         removed = (u - buffer) + 1;
 162                         memmove(buffer, u, (sizeof(buffer) - left) - removed);
 163                         s -= removed;
 164                         left += removed;
 165                 }
 166
 167                 do {
 168                         t = strchr(buffer, '\n');
 169                         if (t == NULL)
 170                                 break;
 171
 172                         *t++ = '\0';
 173                         for (u = buffer; isdigit((unsigned char)*u) ||
 174                             (*u == '.'); u++)
 175                                 continue;
 176                         if (*u == '/') {
 177                                 char *slash;
 178
 179                                 slash = u;
 180                                 u++;
 181                                 while (isdigit((unsigned char)*u))
 182                                         u++;
 183                                 if (!isspace((unsigned char)*u) && *u)
 184                                         u = slash;
 185                         }
 186                         *u = '\0';
 187
 188                         a = alist_new(4, buffer);
 189                         if (a != NULL) {
 190                                 if (rbot != NULL)
 191                                         rbot->al_next = a;
 192                                 else
 193                                         rtop = a;
 194                                 rbot = a;
 195                         }
 196
 197                         removed = t - buffer;
 198                         memmove(buffer, t, sizeof(buffer) - left - removed);
 199                         s -= removed;
 200                         left += removed;
 201
 202                 } while (1);
 203         }
 204
 205 done:
 206         if (myurl != NULL)
 207                 free(myurl);
 208         if (fd != -1)
 209                 close(fd);
 210         return rtop;
 211 }