nntp.c

   1 /*
   2  * nntp.c
   3  * Created: Sun Feb 25 20:37:47 2001 by tek@wiw.org
   4  * Revised: Sun Feb 25 20:37:47 2001 (pending)
   5  * Copyright 2001 Julian E. C. Squires (tek@wiw.org)
   6  * This program comes with ABSOLUTELY NO WARRANTY.
   7  * $Id: nntp.c,v 1.2 2001/02/26 06:00:54 tek Exp $
   8  *
   9  */
  10
  11 #include <errno.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <string.h>
  15 #include <unistd.h>
  16
  17 #include <netdb.h>
  18 #include <sys/types.h>
  19 #include <sys/socket.h>
  20 #include <sys/time.h>
  21 #include <netinet/in.h>
  22
  23 #include "noose.h"
  24
  25 #define OURMAGIC    0xDEADBEEF
  26 #define NNTPSERVICE "nntp"
  27 #define NNTPPROTO   "tcp"
  28
  29 typedef struct nntp_s {
  30     long magic;
  31     int sock;
  32 } nntp_t;
  33
  34 void *nntp_connect(char *hostname);
  35 void nntp_disconnect(void *nh_);
  36 int nntp_cmd_group(void *nh_, char *group, int *narticles_, int *firstart_,
  37                    int *lastart_);
  38 int nntp_cmd_article(void *nh_, int artnum, char **head, char **body);
  39
  40 static int nntp_readresponse(nntp_t *nh, char **resbody);
  41 static int nntp_readheader(nntp_t *nh, char **header);
  42 static int nntp_readbody(nntp_t *nh, char **body);
  43
  44 static char *responses[6][5][10] = {
  45     { { "" } }, /* 0 */
  46     { { "" } }, /* 1 */
  47     { { "" } }, /* 2 */
  48     { { "" } }, /* 3 */
  49     /* 4** */
  50     {   /* 40* */
  51         { "Service discontinued." /* 400 */
  52           "", "", "", "", "", "", "", "", "" },
  53         /* 41* */
  54         { "", /* 410 */
  55           "No such news group.", /* 411 */
  56           "No newsgroup has been selected.", /* 412 */
  57           "", "", "", "", "", "", "" },
  58         /* 42* */
  59         { "No current article has been selected.", /* 420 */
  60           "No next article in this group.", /* 421 */
  61           "No previous article in this group.", /* 422 */
  62           "No such article number in this group.", /* 423 */
  63           "", "", "", "", "", "" },
  64         /* 43* */
  65         { "No such article found.", /* 430 */
  66           "", "", "", "",
  67           "Article not wanted - do not send it.", /* 435 */
  68           "Transfer failed - try again later.", /* 436 */
  69           "Article rejected - do not try again.", /* 437 */
  70           "", "" },
  71         /* 44* */
  72         { "Posting not allowed.", /* 440 */
  73           "Posting failed.", /* 441 */
  74           "", "", "", "", "", "", "", "" }
  75     },
  76
  77     /* 5** */
  78     {
  79         /* 50* */
  80         { "Command not recognized.", /* 500 */
  81           "Command syntax error.", /* 501 */
  82           "Access restriction or permission denied.", /* 502 */
  83           "Program fault - command not performed.", /* 503 */
  84           "", "", "", "", "", "" }
  85     }
  86 };
  87
  88 void *nntp_connect(char *hostname)
  89 {
  90     nntp_t *nh;
  91     struct hostent *hostent;
  92     struct servent *servent;
  93     struct sockaddr_in sockaddr;
  94     int i;
  95
  96     nh = malloc(sizeof(nntp_t));
  97     if(nh == NULL) {
  98         fprintf(stderr, "%s: Out of memory.\n", PROGNAME);
  99         return NULL;
 100     }
 101
 102     nh->magic = OURMAGIC;
 103     nh->sock = socket(AF_INET, SOCK_STREAM, 0);
 104     if(nh->sock == -1) {
 105         fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 106         return NULL;
 107     }
 108
 109     sockaddr.sin_family = AF_INET;
 110     hostent = gethostbyname(hostname);
 111     if(hostent == NULL) {
 112         fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 113         return NULL;
 114     }
 115     memcpy(&sockaddr.sin_addr, hostent->h_addr_list[0], hostent->h_length);
 116
 117     servent = getservbyname(NNTPSERVICE, NNTPPROTO);
 118     if(servent == NULL) {
 119         fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 120         return NULL;
 121     }
 122     sockaddr.sin_port = servent->s_port;
 123
 124     if(connect(nh->sock, (const struct sockaddr *)&sockaddr,
 125                sizeof(sockaddr)) == -1) {
 126         fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 127         return NULL;
 128     }
 129
 130     i = nntp_readresponse(nh, NULL);
 131     if(i != 200) {
 132         fprintf(stderr, "%s: %s\n", PROGNAME, responses[i/100][i/10%10][i%10]);
 133         return NULL;
 134     }
 135
 136     return (void *)nh;
 137 }
 138
 139 int nntp_readresponse(nntp_t *nh, char **resbody)
 140 {
 141     char *buffer;
 142     int respnum, blen = 128, i, bufp;
 143
 144     buffer = malloc(blen);
 145     if(buffer == NULL) {
 146         fprintf(stderr, "%s: Out of memory in nntp_readresponse.\n",
 147                 PROGNAME);
 148         return 0;
 149     }
 150     bufp = 0;
 151
 152     do {
 153         i = read(nh->sock, buffer+bufp, 1);
 154         if(i == -1) {
 155             fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 156             return 0;
 157         }
 158
 159         bufp += i;
 160
 161         if(bufp >= blen) {
 162             blen *= 2;
 163             buffer = realloc(buffer, blen);
 164             if(buffer == NULL) {
 165                 fprintf(stderr, "%s: Out of memory in "
 166                         "nntp_readresponse.\n", PROGNAME);
 167                 return 0;
 168             }
 169         }
 170     } while(!(buffer[bufp-2] == '\r' && buffer[bufp-1] == '\n'));
 171     buffer[bufp] = 0;
 172
 173     respnum = atoi(buffer);
 174     if(resbody != NULL)
 175         *resbody = buffer;
 176     else
 177         free(buffer);
 178
 179     return respnum;
 180 }
 181
 182 int nntp_readheader(nntp_t *nh, char **header)
 183 {
 184     char *buffer;
 185     int blen = 128, i, bufp;
 186
 187     buffer = malloc(blen);
 188     if(buffer == NULL) {
 189         fprintf(stderr, "%s: Out of memory in nntp_readheader.\n",
 190                 PROGNAME);
 191         return -1;
 192     }
 193     bufp = 0;
 194
 195     do {
 196         i = read(nh->sock, buffer+bufp, 1);
 197         if(i == -1) {
 198             fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 199             return -1;
 200         }
 201
 202         bufp += i;
 203
 204         if(bufp >= blen) {
 205             blen *= 2;
 206             buffer = realloc(buffer, blen);
 207             if(buffer == NULL) {
 208                 fprintf(stderr, "%s: Out of memory in "
 209                         "nntp_readheader.\n", PROGNAME);
 210                 return -1;
 211             }
 212         }
 213     } while(!(buffer[bufp-1] == '\n' &&
 214               buffer[bufp-2] == '\r' &&
 215               (buffer[bufp-3] == '.' ||
 216                (buffer[bufp-3] == '\n' &&
 217                 buffer[bufp-4] == '\r'))));
 218     buffer[bufp] = 0;
 219
 220     if(header != NULL)
 221         *header = buffer;
 222     else
 223         free(buffer);
 224
 225     return 0;
 226 }
 227
 228 int nntp_readbody(nntp_t *nh, char **body)
 229 {
 230     char *buffer;
 231     int blen = 128, i, bufp;
 232
 233     buffer = malloc(blen);
 234     if(buffer == NULL) {
 235         fprintf(stderr, "%s: Out of memory in nntp_readbody.\n", PROGNAME);
 236         return -1;
 237     }
 238     bufp = 0;
 239
 240     do {
 241         i = read(nh->sock, buffer+bufp, 1);
 242         if(i == -1) {
 243             fprintf(stderr, "%s: %s\n", PROGNAME, strerror(errno));
 244             return -1;
 245         }
 246
 247         bufp += i;
 248
 249         if(bufp >= blen) {
 250             blen *= 2;
 251             buffer = realloc(buffer, blen);
 252             if(buffer == NULL) {
 253                 fprintf(stderr, "%s: Out of memory in "
 254                         "nntp_readbody.\n", PROGNAME);
 255                 return -1;
 256             }
 257         }
 258     } while(!(buffer[bufp-1] == '\n' &&
 259               buffer[bufp-2] == '\r' &&
 260               buffer[bufp-3] == '.' &&
 261               buffer[bufp-4] == '\n' &&
 262               buffer[bufp-5] == '\r'));
 263     buffer[bufp-3] = 0;
 264
 265     if(body != NULL)
 266         *body = buffer;
 267     else
 268         free(buffer);
 269
 270     return 0;
 271 }
 272
 273 void nntp_disconnect(void *nh_)
 274 {
 275     nntp_t *nh = (nntp_t *)nh_;
 276
 277     if(nh->magic != OURMAGIC) {
 278         fprintf(stderr, "%s: magic check failed for nntp_disconnect!\n",
 279                 PROGNAME);
 280     }
 281
 282     write(nh->sock, "QUIT\r\n", strlen("QUIT\r\n"));
 283     close(nh->sock);
 284
 285     return;
 286 }
 287
 288 int nntp_cmd_group(void *nh_, char *group, int *narticles, int *firstart,
 289                    int *lastart)
 290 {
 291     nntp_t *nh = (nntp_t *)nh_;
 292     int i;
 293     char *respbody, *p, *cmdbuf;
 294
 295     if(nh->magic != OURMAGIC) {
 296         fprintf(stderr, "%s: magic check failed for nntp_cmd_group!\n",
 297                 PROGNAME);
 298     }
 299
 300     cmdbuf = malloc(strlen("GROUP ")+strlen(group)+strlen("\r\n"));
 301     strcpy(cmdbuf, "GROUP ");
 302     strcat(cmdbuf, group);
 303     strcat(cmdbuf, "\r\n");
 304     write(nh->sock, cmdbuf, strlen(cmdbuf));
 305     free(cmdbuf);
 306
 307     i = nntp_readresponse(nh, &respbody);
 308     if(i != 211) {
 309         fprintf(stderr, "%s: %s\n", PROGNAME, responses[i/100][i/10%10][i%10]);
 310         return -1;
 311     }
 312
 313     p = strtok(respbody, " \t\n");
 314     /* response code */
 315     p = strtok(NULL, " \t\n");
 316     if(narticles != NULL) *narticles = atoi(p);
 317     p = strtok(NULL, " \t\n");
 318     if(firstart != NULL) *firstart = atoi(p);
 319     p = strtok(NULL, " \t\n");
 320     if(lastart != NULL) *lastart = atoi(p);
 321     /* next would be group name */
 322
 323     free(respbody);
 324     return 0;
 325 }
 326
 327 #define MAXARTNUMLEN 10
 328
 329 int nntp_cmd_article(void *nh_, int artnum, char **head, char **body)
 330 {
 331     nntp_t *nh = (nntp_t *)nh_;
 332     int i;
 333     char *respbody, *cmdbuf, *cmd;
 334
 335     if(nh->magic != OURMAGIC) {
 336         fprintf(stderr, "%s: magic check failed for nntp_cmd_article!\n",
 337                 PROGNAME);
 338     }
 339
 340     if(head == NULL && body == NULL)
 341         cmd = "STAT ";
 342     else if(head == NULL)
 343         cmd = "BODY ";
 344     else if(body == NULL)
 345         cmd = "HEAD ";
 346     else
 347         cmd = "ARTICLE ";
 348     cmdbuf = malloc(strlen(cmd)+MAXARTNUMLEN+strlen("\r\n"));
 349     sprintf(cmdbuf, "%s %d\r\n", cmd, artnum);
 350     write(nh->sock, cmdbuf, strlen(cmdbuf));
 351     free(cmdbuf);
 352
 353     i = nntp_readresponse(nh, &respbody);
 354     if(i/10 != 22) {
 355         fprintf(stderr, "%s: %s\n", PROGNAME, responses[i/100][i/10%10][i%10]);
 356         return -1;
 357     }
 358     if(head != NULL)
 359         if(nntp_readheader(nh, head) != 0) {
 360             fprintf(stderr, "%s: failed to read header.\n", PROGNAME);
 361             return -1;
 362         }
 363     if(body != NULL)
 364         if(nntp_readbody(nh, body) != 0) {
 365             fprintf(stderr, "%s: failed to read body.\n", PROGNAME);
 366             return -1;
 367         }
 368
 369     return 0;
 370 }
 371
 372 /* EOF nntp.c */