src/network/pop3.c

   1 /**
   2  * Copyright (C) 2011 - Roberto Branciforti
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 /* POP3 functions (See RFC 1939) */
  20
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24
  25 #include "socket.h"
  26 #include "socket_io.h"
  27 #include "socket_ssl.h"
  28
  29 #include "pop3.h"
  30
  31 #if 0
  32 #define POP3_DEBUG
  33 #define DEBUG_ERROR     fprintf(stderr, "%s:%d - %s\n", __FILE__, __LINE__, __func__)
  34 #endif
  35
  36 #define POP3_TIMEOUT    3  /* seconds */
  37
  38 static void print_server_response(const char *buf)
  39 {
  40         size_t i;
  41         for (i = 0; i < strlen(buf); i++) {
  42                 if (buf[i] == '\r')
  43                         fprintf(stderr, "\\r");
  44                 else if (buf[i] == '\n')
  45                         fprintf(stderr, "\\n");
  46                 else if (buf[i] == '\t')
  47                         fprintf(stderr, "\\t");
  48                 else if ((buf[i] < ' ') || (buf[i] > 0x7E))
  49                         fprintf(stderr, "0x%02X ", buf[i]);
  50                 else
  51                         fprintf(stderr, "%c", buf[i]);
  52         }
  53         fprintf(stderr, "\n");
  54 }
  55
  56 /**
  57  * Test for an OK response
  58  *
  59  * @param[in] buf       server response line buffer
  60  *
  61  * @retval 1 +OK, 0 on -ERR response
  62  */
  63 static int pop3_command_success(const char *buf)
  64 {
  65 #ifdef POP3_DEBUG
  66         print_server_response(buf);
  67 #endif
  68         if (strstr(buf, "+OK") != NULL)
  69                 return 1;
  70
  71         return 0;
  72 }
  73
  74 static int pop3_send_command(struct pop3_mailbox *mbox, const char *cmd, size_t cmd_size)
  75 {
  76         ssize_t rc;
  77
  78         if (POP3_AUTH_SSL == mbox->auth.type) {
  79                 rc = socket_ssl_write(&mbox->auth.ssl.ctx, cmd, cmd_size);
  80         } else {
  81                 rc = socket_write(mbox->host.sockfd, cmd, cmd_size);
  82         }
  83
  84         if (rc < 0)
  85                 return -1;
  86
  87         /* Now wr >= 0 and it's safe to cast it to size_t */
  88         if (cmd_size != (size_t) rc)
  89                 return -1;
  90
  91         return 0;
  92 }
  93
  94 static int pop3_get_reply(struct pop3_mailbox *mbox, char *line, size_t lsize)
  95 {
  96         if (POP3_AUTH_SSL == mbox->auth.type) {
  97                 return socket_ssl_read_line(&mbox->auth.ssl.ctx, line, lsize);
  98         }
  99
 100         return socket_read_line(mbox->host.sockfd, line, lsize, POP3_TIMEOUT);
 101 }
 102
 103 static int pop3_command(struct pop3_mailbox *mbox, const char *cmd, size_t csize)
 104 {
 105         char line[POP3_BUFSIZE];
 106
 107         if (pop3_send_command(mbox, cmd, csize) < 0) {
 108                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 109                 return -1;
 110         }
 111
 112         if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 113                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 114                 return -1;
 115         }
 116
 117         if (strstr(line, "+OK") == NULL) {
 118                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 119                 return -1;
 120         }
 121
 122         return 0;
 123 }
 124
 125 /**
 126  * Test the end of pop3
 127  *
 128  * @param[in] buf       server response line buffer
 129  *
 130  * @retval 1 if EOS, 0 otherwise
 131  */
 132 static int pop3_end_scan(const char *buf)
 133 {
 134         if ((buf[0] == '.') && ((buf[1] == '\r') || (buf[1] == '\n')))
 135                 return 1;
 136
 137         return 0;
 138 }
 139
 140 int pop3_connect(struct pop3_mailbox *mbox)
 141 {
 142         struct pop3_auth_ssl *ssl;
 143
 144         int sockfd;
 145         int rc;
 146
 147         char buf[POP3_BUFSIZE];
 148
 149         sockfd = connect_to_tcp_server(mbox->host.name, mbox->host.port);
 150         if (sockfd < 0) {
 151                 return -1;
 152         }
 153
 154         mbox->host.sockfd = sockfd;
 155
 156 #ifdef POP3_DEBUG
 157         fprintf(stderr, "%s sockfd %d\n", __func__, sockfd);
 158 #endif
 159
 160         ssl = &mbox->auth.ssl;
 161
 162         if (POP3_AUTH_SSL == mbox->auth.type) {
 163                 if (socket_ssl_init(&mbox->host.sockfd, &ssl->ctx, &ssl->ssn, &ssl->hs, &ssl->cert, NULL)) {
 164                         return -1;
 165                 }
 166
 167                 rc = socket_ssl_read_line(&mbox->auth.ssl.ctx, buf, POP3_BUFSIZE);
 168         } else {
 169                 /* !SSL */
 170                 rc = socket_read_line(sockfd, buf, sizeof(buf), POP3_TIMEOUT);
 171         }
 172
 173         /* Once the TCP connection has been opened by a POP3 client,
 174          * the POP3 server issues a one line greeting.
 175          */
 176 #ifdef POP3_DEBUG
 177         print_server_response(buf);
 178 #endif
 179         if (rc < 0) {
 180                 return -1;
 181         }
 182
 183         if (!pop3_command_success(buf)) {
 184                 return -1;
 185         }
 186
 187         return 0;
 188 }
 189
 190 int pop3_disconnect(struct pop3_mailbox *mbox)
 191 {
 192         (void) pop3_command(mbox, "QUIT\r\n", 6);
 193
 194         if (POP3_AUTH_SSL == mbox->auth.type) {
 195                 return socket_ssl_close(mbox->host.sockfd,
 196                                         &mbox->auth.ssl.ctx,
 197                                         &mbox->auth.ssl.cert);
 198         }
 199
 200         return socket_close(mbox->host.sockfd);
 201 }
 202
 203 int pop3_authenticate(struct pop3_mailbox *mbox)
 204 {
 205         int n;
 206         char line[POP3_BUFSIZE];
 207
 208         if ((mbox->auth.type != POP3_AUTH_USERPASS) &&
 209             (mbox->auth.type != POP3_AUTH_SSL)) {
 210
 211                 fprintf(stderr, "%s - Invalid POP3_AUTH_TYPE %d\n",
 212                                 __func__, mbox->auth.type);
 213                 return -1;
 214         }
 215
 216         n = snprintf(line, POP3_BUFSIZE, "USER %s\r\n", mbox->auth.user);
 217         if (pop3_command(mbox, line, n)) {
 218                 fprintf(stderr, "%s - Invalid user\n", __func__);
 219                 return -1;
 220         }
 221
 222         n = snprintf(line, POP3_BUFSIZE, "PASS %s\r\n", mbox->auth.pass);
 223         if (pop3_command(mbox, line, n)) {
 224                 fprintf(stderr, "%s - Invalid password\n", __func__);
 225                 return -1;
 226         }
 227
 228         return 0;
 229 }
 230
 231 int pop3_capa(struct pop3_mailbox *mbox)
 232 {
 233         char line[POP3_BUFSIZE];
 234         int scan_end;
 235
 236         if (pop3_command(mbox, "CAPA\r\n", 6)) {
 237                 return -1;
 238         }
 239
 240         scan_end = 0;
 241         while (!scan_end) {
 242                 if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 243                         fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 244                         return -1;
 245                 } else {
 246                         fprintf(stderr, "%s - line %s\n", __func__, line);
 247                 }
 248
 249                 scan_end = pop3_end_scan(line);
 250
 251                 /* Prints the scan-list entry */
 252                 print_server_response(line);
 253         }
 254
 255         return 0;
 256 }
 257
 258 int pop3_stat(struct pop3_mailbox *mbox)
 259 {
 260         int n;
 261         unsigned int msgs;
 262         unsigned long octets = 0;
 263
 264         char line[POP3_BUFSIZE];
 265
 266         if (pop3_send_command(mbox, "STAT\r\n", 6)) {
 267                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 268                 return -1;
 269         }
 270
 271         if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 272                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 273                 return -1;
 274         }
 275
 276         /* Reset message counter */
 277         mbox->messages = 0;
 278         /* [RFC 1939]...
 279          * The positive response consists of "+OK" followed by a single space,
 280          * the number of messages in the maildrop, a single space, and the
 281          * size of the maildrop in octets.
 282          */
 283         n = sscanf(line, "+OK %u %lu", &msgs, &octets);
 284         if (n >= 0) {
 285                 mbox->messages = msgs;
 286         } else {
 287                 fprintf(stderr, "%s - Error parsing %s\n", __func__, line);
 288                 return -1;
 289         }
 290
 291         return 0;
 292 }
 293
 294 int pop3_list(struct pop3_mailbox *mbox)
 295 {
 296         char line[POP3_BUFSIZE];
 297         int scan_end;
 298
 299         if (pop3_command(mbox, "LIST\r\n", 6)) {
 300                 return -1;
 301         }
 302
 303         scan_end = 0;
 304         while (!scan_end) {
 305                 if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 306                         return -1;
 307                 }
 308
 309                 scan_end = pop3_end_scan(line);
 310
 311                 /* Prints the scan-list entry */
 312                 print_server_response(line);
 313         }
 314
 315         return 0;
 316 }
 317
 318 int pop3_top(struct pop3_mailbox *mbox, unsigned int msg_num)
 319 {
 320         char snd[POP3_BUFSIZE];
 321         char buf[POP3_BUFSIZE];
 322
 323         int scan_end;
 324         int n;
 325
 326         if (msg_num > mbox->messages) {
 327                 fprintf(stderr, "%s - BUG: msg_num %u > mbox.messages %u",
 328                          __func__, msg_num, mbox->messages);
 329                 return -1;
 330         }
 331
 332         n = snprintf(snd, POP3_BUFSIZE, "TOP %u 0\r\n", msg_num);
 333
 334         if (pop3_send_command(mbox, snd, n)) {
 335                 return -1;
 336         }
 337
 338         scan_end = 0;
 339         while (!scan_end) {
 340                 if (socket_read_line(mbox->host.sockfd, buf, POP3_BUFSIZE, POP3_TIMEOUT) < 0)
 341                         return -1;
 342
 343                 scan_end = pop3_end_scan(buf);
 344
 345                 /* Prints the scan-list entry */
 346                 print_server_response(buf);
 347         }
 348         return 0;
 349 }
 350
 351 int pop3_retr(struct pop3_mailbox *mbox, unsigned int msg_num)
 352 {
 353         char snd[POP3_BUFSIZE];
 354         char buf[POP3_BUFSIZE];
 355         int scan_end;
 356         int n;
 357
 358         if (msg_num > mbox->messages) {
 359                 fprintf(stderr, "%s - BUG: msg_num %u > mbox.messages %u",
 360                          __func__, msg_num, mbox->messages);
 361                 return -1;
 362         }
 363
 364         n = snprintf(snd, POP3_BUFSIZE, "RETR %u\r\n", msg_num);
 365
 366         if (pop3_send_command(mbox, snd, n)) {
 367                 return -1;
 368         }
 369
 370         scan_end = 0;
 371         while (!scan_end) {
 372                 if (socket_read_line(mbox->host.sockfd, buf, POP3_BUFSIZE, POP3_TIMEOUT) < 0)
 373                         return -1;
 374
 375                 scan_end = pop3_end_scan(buf);
 376
 377                 /* Prints the scan-list entry */
 378                 print_server_response(buf);
 379         }
 380         return 0;
 381 }