pop3.c

   1 /*
   2  * pop3 - a simple pop3 mail client
   3  *
   4  * Copyright (C) 2010 Ali Gholami Rudi
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License, as published by the
   8  * Free Software Foundation.
   9  */
  10 #include <arpa/inet.h>
  11 #include <ctype.h>
  12 #include <errno.h>
  13 #include <fcntl.h>
  14 #include <netdb.h>
  15 #include <netinet/in.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <sys/socket.h>
  20 #include <sys/stat.h>
  21 #include <sys/types.h>
  22 #include <time.h>
  23 #include <unistd.h>
  24 #include "config.h"
  25
  26 #define BUFFSIZE                (1 << 12)
  27 #define ARRAY_SIZE(a)           (sizeof(a) / sizeof((a)[0]))
  28 #define MIN(a, b)               ((a) < (b) ? (a) : (b))
  29
  30 struct mailinfo {
  31         char name[1 << 4];
  32         int size;
  33 } mails[MAXMAILS];
  34 int nmails;
  35
  36 static int fd;
  37 static char buf[BUFFSIZE];
  38 static char *buf_cur;
  39 static char *buf_end;
  40
  41 #ifdef SSL
  42 #include <polarssl/ssl.h>
  43 #include <polarssl/havege.h>
  44
  45 static ssl_context ssl;
  46 static ssl_session ssn;
  47 static havege_state hs;
  48
  49 static int ps_send(void *ctx, unsigned char *buf, int len)
  50 {
  51         return write(*(int *) ctx, buf, len);
  52 }
  53
  54 static int ps_recv(void *ctx, unsigned char *buf, int len)
  55 {
  56         return read(*(int *) ctx, buf, len);
  57 }
  58
  59 #endif
  60
  61 static int pop3_connect(char *addr, char *port)
  62 {
  63         struct addrinfo hints, *addrinfo;
  64         int fd;
  65
  66         memset(&hints, 0, sizeof(hints));
  67         hints.ai_family = AF_UNSPEC;
  68         hints.ai_socktype = SOCK_STREAM;
  69         hints.ai_flags = AI_PASSIVE;
  70
  71         getaddrinfo(addr, port, &hints, &addrinfo);
  72         fd = socket(addrinfo->ai_family, addrinfo->ai_socktype,
  73                         addrinfo->ai_protocol);
  74
  75         if (connect(fd, addrinfo->ai_addr, addrinfo->ai_addrlen) == -1) {
  76                 close(fd);
  77                 freeaddrinfo(addrinfo);
  78                 return -1;
  79         }
  80         freeaddrinfo(addrinfo);
  81         return fd;
  82 }
  83
  84 static void print(char *buf, int len)
  85 {
  86         write(STDOUT_FILENO, buf, len);
  87 }
  88
  89 static int reply_line(char *dst, int len)
  90 {
  91         int nr = 0;
  92         char *nl;
  93         while (nr < len) {
  94                 int ml;
  95                 if (!buf_cur || buf_cur >= buf_end) {
  96 #ifdef SSL
  97                         int buf_len = ssl_read(&ssl, (unsigned char *) buf,
  98                                                 sizeof(buf));
  99 #else
 100                         int buf_len = read(fd, buf, sizeof(buf));
 101 #endif
 102                         if (buf_len <= 0)
 103                                 return -1;
 104 #ifdef DEBUG
 105                         print(buf, buf_len);
 106 #endif
 107                         buf_cur = buf;
 108                         buf_end = buf + buf_len;
 109                 }
 110                 ml = MIN(buf_end - buf_cur, len - nr);
 111                 if ((nl = memchr(buf_cur, '\n', ml))) {
 112                         nl++;
 113                         memcpy(dst + nr, buf_cur, nl - buf_cur);
 114                         nr += nl - buf_cur;
 115                         buf_cur = nl;
 116                         return nr;
 117                 }
 118                 memcpy(dst + nr, buf_cur, ml);
 119                 nr += ml;
 120                 buf_cur += ml;
 121         }
 122         return nr;
 123 }
 124
 125 static void send_cmd(char *cmd)
 126 {
 127 #ifdef SSL
 128         ssl_write(&ssl, (unsigned char *) cmd, strlen(cmd));
 129 #else
 130         write(fd, cmd, strlen(cmd));
 131 #endif
 132         fsync(fd);
 133 #ifdef DEBUG
 134         print(cmd, strlen(cmd));
 135 #endif
 136 }
 137
 138 static int is_eoc(char *line, int len)
 139 {
 140         return len < 4 && line[0] == '.' &&
 141                 (line[1] == '\r' || line[1] == '\n');
 142 }
 143
 144 static char *putmem(char *dst, char *src, int len)
 145 {
 146         memcpy(dst, src, len);
 147         return dst + len;
 148 }
 149
 150 static char *cutword(char *dst, char *s)
 151 {
 152         while (*s && isspace(*s))
 153                 s++;
 154         while (*s && !isspace(*s))
 155                 *dst++ = *s++;
 156         *dst = '\0';
 157         return s;
 158 }
 159
 160 static char *putstr(char *dst, char *src)
 161 {
 162         int len = strchr(src, '\0') - src;
 163         memcpy(dst, src, len + 1);
 164         return dst + len;
 165 }
 166
 167 static void login(char *user, char *pass)
 168 {
 169         char line[BUFFSIZE];
 170         int len;
 171         char *s = line;
 172         s = putstr(s, "USER ");
 173         s = putstr(s, user);
 174         s = putstr(s, "\n");
 175         send_cmd(line);
 176         len = reply_line(line, sizeof(line));
 177         s = line;
 178         s = putstr(s, "PASS ");
 179         s = putstr(s, pass);
 180         s = putstr(s, "\n");
 181         send_cmd(line);
 182         len = reply_line(line, sizeof(line));
 183 }
 184
 185 static void mail_stat(void)
 186 {
 187         char line[BUFFSIZE];
 188         int len;
 189         send_cmd("STAT\n");
 190         len = reply_line(line, sizeof(line));
 191         print(line, len);
 192         send_cmd("LIST\n");
 193         len = reply_line(line, sizeof(line));
 194         while ((len = reply_line(line, sizeof(line))) != -1) {
 195                 struct mailinfo *mail;
 196                 char *s = line;
 197                 if (is_eoc(line, len))
 198                         break;
 199                 mail = &mails[nmails++];
 200                 s = cutword(mail->name, s);
 201                 mail->size = atoi(s);
 202         }
 203 }
 204
 205 static void req_mail(int i)
 206 {
 207         char cmd[100];
 208         char *s = cmd;
 209         s = putstr(s, "RETR ");
 210         s = putstr(s, mails[i].name);
 211         s = putstr(s, "\n");
 212         send_cmd(cmd);
 213 }
 214
 215 static char *mail_dst(char *line, int len)
 216 {
 217         int i;
 218         line[len] = '\0';
 219         for (i = 0; i < ARRAY_SIZE(filters); i++) {
 220                 char *hdr = filters[i].hdr;
 221                 if (!strncmp(hdr, line, strlen(hdr)) &&
 222                                 strstr(line, filters[i].val))
 223                         return filters[i].dst;
 224         }
 225         return NULL;
 226 }
 227
 228 int xwrite(int fd, char *buf, int len)
 229 {
 230         int nw = 0;
 231         while (nw < len) {
 232                 int ret = write(fd, buf + nw, len - nw);
 233                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
 234                         continue;
 235                 if (ret < 0)
 236                         break;
 237                 nw += ret;
 238         }
 239         return nw;
 240 }
 241
 242 static int mail_write(char *dst, char *mail, int len)
 243 {
 244         int fd = open(dst, O_WRONLY | O_APPEND | O_CREAT, 0600);
 245         if (fd == -1)
 246                 return -1;
 247         if (xwrite(fd, mail, len) != len)
 248                 return -1;
 249         close(fd);
 250         return 0;
 251 }
 252
 253 static char *put_from_(char *s)
 254 {
 255         time_t t;
 256         time(&t);
 257         s = putstr(s, "From ");
 258         s = putstr(s, getlogin());
 259         s += strftime(s, MAXSIZE, " %a %b %d %H:%M:%S %Y\n", localtime(&t));
 260         return s;
 261 }
 262
 263 static int ret_mail(int i)
 264 {
 265         char mail[MAXSIZE];
 266         char line[BUFFSIZE];
 267         char *s = mail;
 268         int len = reply_line(line, sizeof(line));
 269         char *dst = NULL;
 270         int hdr = 1;
 271         int ret;
 272         if (mails[i].size + 100 > sizeof(mail))
 273                 return -1;
 274         print(mails[i].name, strlen(mails[i].name));
 275         s = put_from_(s);
 276         while ((len = reply_line(line, sizeof(line))) != -1) {
 277                 if (is_eoc(line, len))
 278                         break;
 279                 if (len > 1 && line[len - 2] == '\r')
 280                         line[len-- - 2] = '\n';
 281                 if (line[0] == '\n')
 282                         hdr = 0;
 283                 if (hdr && !dst)
 284                         dst = mail_dst(line, len);
 285                 s = putmem(s, line, len);
 286         }
 287         *s++ = '\n';
 288         if (!dst)
 289                 dst = SPOOL;
 290         ret = mail_write(dst, mail, s - mail);
 291         s = line;
 292         s = putstr(s, " -> ");
 293         s = putstr(s, dst);
 294         s = putstr(s, "\n");
 295         print(line, s - line);
 296         return ret;
 297 }
 298
 299 static void del_mail(int i)
 300 {
 301         char cmd[100];
 302         char *s = cmd;
 303         s = putstr(s, "DELE ");
 304         s = putstr(s, mails[i].name);
 305         s = putstr(s, "\n");
 306         send_cmd(cmd);
 307 }
 308
 309 static int fetch(struct account *account)
 310 {
 311         char line[BUFFSIZE];
 312         int len;
 313         int i;
 314         char *s = line;
 315         nmails = 0;
 316         fd = pop3_connect(account->server, account->port);
 317         if (fd == -1)
 318                 return 1;
 319         s = putstr(s, "fetching ");
 320         s = putstr(s, account->user);
 321         s = putstr(s, "@");
 322         s = putstr(s, account->server);
 323         s = putstr(s, "\n");
 324         print(line, s - line);
 325 #ifdef SSL
 326         havege_init(&hs);
 327         memset(&ssn, 0, sizeof(ssn));
 328         if (ssl_init(&ssl))
 329                 return 1;
 330         ssl_set_endpoint(&ssl, SSL_IS_CLIENT);
 331         ssl_set_authmode(&ssl, SSL_VERIFY_NONE);
 332         ssl_set_rng(&ssl, havege_rand, &hs);
 333         ssl_set_bio(&ssl, ps_recv, &fd, ps_send, &fd);
 334         ssl_set_ciphers(&ssl, ssl_default_ciphers);
 335         ssl_set_session(&ssl, 1, 600, &ssn);
 336 #endif
 337         len = reply_line(line, sizeof(line));
 338         login(account->user, account->pass);
 339         mail_stat();
 340         for (i = 0; i < nmails; i++)
 341                 req_mail(i);
 342         for (i = 0; i < nmails; i++)
 343                 if (ret_mail(i) == -1)
 344                         return 1;
 345         if (DELMAILS) {
 346                 for (i = 0; i < nmails; i++)
 347                         del_mail(i);
 348                 for (i = 0; i < nmails; i++)
 349                         len = reply_line(line, sizeof(line));
 350         }
 351         send_cmd("QUIT\n");
 352         len = reply_line(line, sizeof(line));
 353 #ifdef SSL
 354         ssl_close_notify(&ssl);
 355 #endif
 356         close(fd);
 357 #ifdef SSL
 358         ssl_free(&ssl);
 359 #endif
 360         return 0;
 361 }
 362
 363 int main(int argc, char *argv[])
 364 {
 365         int i;
 366         for (i = 0; i < ARRAY_SIZE(accounts); i++)
 367                 if (fetch(&accounts[i]) == -1)
 368                         return 1;
 369         return 0;
 370 }