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         fprintf(stderr, "%s sockfd %d\n", __func__, sockfd);
 157
 158         ssl = &mbox->auth.ssl;
 159
 160         if (POP3_AUTH_SSL == mbox->auth.type) {
 161                 if (socket_ssl_init(&mbox->host.sockfd, &ssl->ctx, &ssl->ssn, &ssl->hs, &ssl->cert, NULL)) {
 162                         return -1;
 163                 }
 164
 165                 rc = socket_ssl_read_line(&mbox->auth.ssl.ctx, buf, POP3_BUFSIZE);
 166         } else {
 167                 /* !SSL */
 168                 rc = socket_read_line(sockfd, buf, sizeof(buf), POP3_TIMEOUT);
 169         }
 170
 171         /* Once the TCP connection has been opened by a POP3 client,
 172          * the POP3 server issues a one line greeting.
 173          */
 174 #ifdef POP3_DEBUG
 175         print_server_response(buf);
 176 #endif
 177         if (rc < 0) {
 178                 return -1;
 179         }
 180
 181         if (!pop3_command_success(buf)) {
 182                 return -1;
 183         }
 184
 185         return 0;
 186 }
 187
 188 int pop3_disconnect(struct pop3_mailbox *mbox)
 189 {
 190         (void) pop3_command(mbox, "QUIT\r\n", 6);
 191
 192         if (POP3_AUTH_SSL == mbox->auth.type) {
 193                 return socket_ssl_close(mbox->host.sockfd,
 194                                         &mbox->auth.ssl.ctx,
 195                                         &mbox->auth.ssl.cert);
 196         }
 197
 198         return socket_close(mbox->host.sockfd);
 199 }
 200
 201 int pop3_authenticate(struct pop3_mailbox *mbox)
 202 {
 203         int n;
 204         char line[POP3_BUFSIZE];
 205
 206         if ((mbox->auth.type != POP3_AUTH_USERPASS) &&
 207             (mbox->auth.type != POP3_AUTH_SSL)) {
 208
 209                 fprintf(stderr, "%s - Invalid POP3_AUTH_TYPE %d\n",
 210                                 __func__, mbox->auth.type);
 211                 return -1;
 212         }
 213
 214         n = snprintf(line, POP3_BUFSIZE, "USER %s\r\n", mbox->auth.user);
 215         if (pop3_command(mbox, line, n)) {
 216                 fprintf(stderr, "%s - Invalid user\n", __func__);
 217                 return -1;
 218         }
 219
 220         n = snprintf(line, POP3_BUFSIZE, "PASS %s\r\n", mbox->auth.pass);
 221         if (pop3_command(mbox, line, n)) {
 222                 fprintf(stderr, "%s - Invalid password\n", __func__);
 223                 return -1;
 224         }
 225
 226         return 0;
 227 }
 228
 229 int pop3_capa(struct pop3_mailbox *mbox)
 230 {
 231         char line[POP3_BUFSIZE];
 232         int scan_end;
 233
 234         if (pop3_command(mbox, "CAPA\r\n", 6)) {
 235                 return -1;
 236         }
 237
 238         scan_end = 0;
 239         while (!scan_end) {
 240                 if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 241                         fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 242                         return -1;
 243                 } else {
 244                         fprintf(stderr, "%s - line %s\n", __func__, line);
 245                 }
 246
 247                 scan_end = pop3_end_scan(line);
 248
 249                 /* Prints the scan-list entry */
 250                 print_server_response(line);
 251         }
 252
 253         return 0;
 254 }
 255
 256 int pop3_stat(struct pop3_mailbox *mbox)
 257 {
 258         int n;
 259         unsigned int msgs;
 260         unsigned long octets = 0;
 261
 262         char line[POP3_BUFSIZE];
 263
 264         if (pop3_send_command(mbox, "STAT\r\n", 6)) {
 265                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 266                 return -1;
 267         }
 268
 269         if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 270                 fprintf(stderr, "%s - line %d\n", __func__, __LINE__);
 271                 return -1;
 272         }
 273
 274         /* Reset message counter */
 275         mbox->messages = 0;
 276         /* [RFC 1939]...
 277          * The positive response consists of "+OK" followed by a single space,
 278          * the number of messages in the maildrop, a single space, and the
 279          * size of the maildrop in octets.
 280          */
 281         n = sscanf(line, "+OK %u %lu", &msgs, &octets);
 282         if (n >= 0) {
 283                 mbox->messages = msgs;
 284         } else {
 285                 fprintf(stderr, "%s - Error parsing %s\n", __func__, line);
 286                 return -1;
 287         }
 288
 289         return 0;
 290 }
 291
 292 int pop3_list(struct pop3_mailbox *mbox)
 293 {
 294         char line[POP3_BUFSIZE];
 295         int scan_end;
 296
 297         if (pop3_command(mbox, "LIST\r\n", 6)) {
 298                 return -1;
 299         }
 300
 301         scan_end = 0;
 302         while (!scan_end) {
 303                 if (pop3_get_reply(mbox, line, POP3_BUFSIZE) < 0) {
 304                         return -1;
 305                 }
 306
 307                 scan_end = pop3_end_scan(line);
 308
 309                 /* Prints the scan-list entry */
 310                 print_server_response(line);
 311         }
 312
 313         return 0;
 314 }
 315
 316 int pop3_top(struct pop3_mailbox *mbox, unsigned int msg_num)
 317 {
 318         char snd[POP3_BUFSIZE];
 319         char buf[POP3_BUFSIZE];
 320
 321         int scan_end;
 322         int n;
 323
 324         if (msg_num > mbox->messages) {
 325                 fprintf(stderr, "%s - BUG: msg_num %u > mbox.messages %u",
 326                          __func__, msg_num, mbox->messages);
 327                 return -1;
 328         }
 329
 330         n = snprintf(snd, POP3_BUFSIZE, "TOP %u 0\r\n", msg_num);
 331
 332         if (pop3_send_command(mbox, snd, n)) {
 333                 return -1;
 334         }
 335
 336         scan_end = 0;
 337         while (!scan_end) {
 338                 if (socket_read_line(mbox->host.sockfd, buf, POP3_BUFSIZE, POP3_TIMEOUT) < 0)
 339                         return -1;
 340
 341                 scan_end = pop3_end_scan(buf);
 342
 343                 /* Prints the scan-list entry */
 344                 print_server_response(buf);
 345         }
 346         return 0;
 347 }
 348
 349 int pop3_retr(struct pop3_mailbox *mbox, unsigned int msg_num)
 350 {
 351         char snd[POP3_BUFSIZE];
 352         char buf[POP3_BUFSIZE];
 353         int scan_end;
 354         int n;
 355
 356         if (msg_num > mbox->messages) {
 357                 fprintf(stderr, "%s - BUG: msg_num %u > mbox.messages %u",
 358                          __func__, msg_num, mbox->messages);
 359                 return -1;
 360         }
 361
 362         n = snprintf(snd, POP3_BUFSIZE, "RETR %u\r\n", msg_num);
 363
 364         if (pop3_send_command(mbox, snd, n)) {
 365                 return -1;
 366         }
 367
 368         scan_end = 0;
 369         while (!scan_end) {
 370                 if (socket_read_line(mbox->host.sockfd, buf, POP3_BUFSIZE, POP3_TIMEOUT) < 0)
 371                         return -1;
 372
 373                 scan_end = pop3_end_scan(buf);
 374
 375                 /* Prints the scan-list entry */
 376                 print_server_response(buf);
 377         }
 378         return 0;
 379 }