pop3.c

   1 /*
   2  * A NEAT POP3 MAIL CLIENT
   3  *
   4  * Copyright (C) 2010-2017 Ali Gholami Rudi
   5  *
   6  * Permission to use, copy, modify, and/or distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18 #include <ctype.h>
  19 #include <errno.h>
  20 #include <fcntl.h>
  21 #include <netdb.h>
  22 #include <signal.h>
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <time.h>
  28 #include <unistd.h>
  29 #include "conf.h"
  30 #include "uidl.h"
  31 #include "conn.h"
  32
  33 #define BUFFSIZE                (1 << 12)
  34 #define ARRAY_SIZE(a)           (sizeof(a) / sizeof((a)[0]))
  35 #define MIN(a, b)               ((a) < (b) ? (a) : (b))
  36
  37 static struct mailinfo {
  38         char name[1 << 4];
  39         char id[1 << 6];
  40         int size;
  41 } mails[MAXMAILS];
  42 static int nmails;
  43 static struct uidl *uidl;
  44
  45 static char buf[BUFFSIZE];
  46 static int buf_len;
  47 static int buf_pos;
  48 static struct conn *conn;
  49 static char *mailbuf;
  50
  51 static int pop3_read(void)
  52 {
  53         if (buf_pos == buf_len) {
  54                 buf_len = conn_read(conn, buf, sizeof(buf));
  55                 buf_pos = 0;
  56         }
  57         return buf_pos < buf_len ? (unsigned char) buf[buf_pos++] : -1;
  58 }
  59
  60 /* read a line from the server */
  61 static int pop3_get(char *dst, int len)
  62 {
  63         int i = 0;
  64         int c;
  65         while (i < len - 1) {
  66                 c = pop3_read();
  67                 if (c < 0)
  68                         return -1;
  69                 dst[i++] = c;
  70                 if (c == '\n')
  71                         break;
  72         }
  73         dst[i] = '\0';
  74         LOG(dst);
  75         return i;
  76 }
  77
  78 /* read a pop3 response line */
  79 static int pop3_res(char *dst, int len)
  80 {
  81         pop3_get(dst, len);
  82         if (dst[0] != '+')
  83                 printf("%s", dst);
  84         return dst[0] != '+';
  85 }
  86
  87 /* send a pop3 command */
  88 static void pop3_cmd(char *cmd, ...)
  89 {
  90         static char buf[512];
  91         va_list ap;
  92         va_start(ap, cmd);
  93         vsnprintf(buf, sizeof(buf), cmd, ap);
  94         va_end(ap);
  95         conn_write(conn, buf, strlen(buf));
  96         LOG(buf);
  97 }
  98
  99 static int pop3_iseoc(char *line, int len)
 100 {
 101         return len >= 2 && len <= 3 && line[0] == '.' &&
 102                 (line[1] == '\r' || line[1] == '\n');
 103 }
 104
 105 static int pop3_login(char *user, char *pass)
 106 {
 107         char line[BUFFSIZE];
 108         pop3_cmd("USER %s\r\n", user);
 109         if (pop3_res(line, sizeof(line)))
 110                 return 1;
 111         pop3_cmd("PASS %s\r\n", pass);
 112         if (pop3_res(line, sizeof(line)))
 113                 return 1;
 114         return 0;
 115 }
 116
 117 static int pop3_stat(void)
 118 {
 119         char line[BUFFSIZE];
 120         int len;
 121         pop3_cmd("STAT\r\n");
 122         if (pop3_res(line, sizeof(line)))
 123                 return 1;
 124         printf("%s", line);
 125         pop3_cmd("LIST\r\n");
 126         if (pop3_res(line, sizeof(line)))
 127                 return 1;
 128         while ((len = pop3_get(line, sizeof(line))) >= 0) {
 129                 struct mailinfo *mail;
 130                 if (pop3_iseoc(line, len))
 131                         break;
 132                 mail = &mails[nmails++];
 133                 sscanf(line, "%s %d", mail->name, &mail->size);
 134         }
 135         return 0;
 136 }
 137
 138 static int pop3_uidl(void)
 139 {
 140         char line[BUFFSIZE];
 141         char name[128];
 142         int len;
 143         int i = 0;
 144         pop3_cmd("UIDL\r\n");
 145         if (pop3_res(line, sizeof(line)))
 146                 return 1;
 147         while ((len = pop3_get(line, sizeof(line))) > 0 && !pop3_iseoc(line, len))
 148                 sscanf(line, "%s %s", name, mails[i++].id);
 149         return 0;
 150 }
 151
 152 static void pop3_retr(int i)
 153 {
 154         pop3_cmd("RETR %s\r\n", mails[i].name);
 155 }
 156
 157 static char *mail_dst(char *hdr, int len)
 158 {
 159         int i;
 160         hdr[len] = '\0';
 161         for (i = 0; i < ARRAY_SIZE(filters); i++)
 162                 if (!strncmp(filters[i].hdr, hdr, strlen(filters[i].hdr)) &&
 163                                 strstr(hdr, filters[i].val))
 164                         return filters[i].dst;
 165         return NULL;
 166 }
 167
 168 static int xwrite(int fd, char *buf, int len)
 169 {
 170         int nw = 0;
 171         while (nw < len) {
 172                 int ret = write(fd, buf + nw, len - nw);
 173                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
 174                         continue;
 175                 if (ret < 0)
 176                         break;
 177                 nw += ret;
 178         }
 179         return nw;
 180 }
 181
 182 static int mail_write(char *dst, char *mail, int len)
 183 {
 184         int fd = open(dst, O_WRONLY | O_APPEND | O_CREAT, 0600);
 185         if (fd < 0)
 186                 return 1;
 187         if (xwrite(fd, mail, len) != len)
 188                 return 1;
 189         close(fd);
 190         return 0;
 191 }
 192
 193 static int mail_from_(char *s)
 194 {
 195         char date[128];
 196         time_t t;
 197         time(&t);
 198         strftime(date, sizeof(date), "%a %b %d %H:%M:%S %Y", localtime(&t));
 199         return sprintf(s, "From %s %s\n", getenv("USER") ? getenv("USER") : "root", date);
 200 }
 201
 202 static int pop3_lonefrom_(char *s)
 203 {
 204         while (*s == '>')
 205                 s++;
 206         return !strncmp("From ", s, 5);
 207 }
 208
 209 static int fetch_one(int i)
 210 {
 211         char line[BUFFSIZE];
 212         char *s = mailbuf;
 213         char *dst = NULL;
 214         int hdr = 1;
 215         int len, ret;
 216         if (pop3_res(line, sizeof(line)))
 217                 return 1;
 218         printf("%s", mails[i].name);
 219         s += mail_from_(s);
 220         while (1) {
 221                 len = pop3_get(line, sizeof(line));
 222                 if (len <= 0)           /* end of stream or error */
 223                         return 1;
 224                 if (pop3_iseoc(line, len))
 225                         break;
 226                 if (len > 1 && line[len - 2] == '\r')
 227                         line[len-- - 2] = '\n';
 228                 if (line[0] == '\n')
 229                         hdr = 0;
 230                 if (hdr && !dst)
 231                         dst = mail_dst(line, len);
 232                 if (pop3_lonefrom_(line))
 233                         *s++ = '>';
 234                 memcpy(s, line, len);
 235                 s += len;
 236         }
 237         *s++ = '\n';
 238         if (!dst)
 239                 dst = SPOOL;
 240         ret = mail_write(dst, mailbuf, s - mailbuf);
 241         printf(" -> %s%s\n", dst, ret ? " [failed]" : "");
 242         return ret;
 243 }
 244
 245 static void pop3_del(int i)
 246 {
 247         pop3_cmd("DELE %s\r\n", mails[i].name);
 248 }
 249
 250 static int size_ok(int i)
 251 {
 252         return mails[i].size + 100 < MAXSIZE;
 253 }
 254
 255 static int uidl_new(int i)
 256 {
 257         return !uidl || !uidl_find(uidl, mails[i].id);
 258 }
 259
 260 static int fetch_mails(int beg, int end, int del)
 261 {
 262         char line[BUFFSIZE];
 263         int i;
 264         for (i = beg; i < end; i++)
 265                 if (size_ok(i) && uidl_new(i))
 266                         pop3_retr(i);
 267         for (i = beg; i < end; i++) {
 268                 if (size_ok(i) && uidl_new(i)) {
 269                         if (fetch_one(i))
 270                                 return 1;
 271                         if (uidl)
 272                                 uidl_add(uidl, mails[i].id);
 273                 }
 274         }
 275         if (del) {
 276                 for (i = beg; i < end; i++)
 277                         if ((!uidl && size_ok(i)) || (uidl && !uidl_new(i)))
 278                                 pop3_del(i);
 279                 for (i = beg; i < end; i++)
 280                         if ((!uidl && size_ok(i)) || (uidl && !uidl_new(i)))
 281                                 pop3_get(line, sizeof(line));
 282         }
 283         return 0;
 284 }
 285
 286 static int fetch(struct account *account)
 287 {
 288         char line[BUFFSIZE];
 289         int batch;
 290         int failed = 0;
 291         int i;
 292         nmails = 0;
 293         conn = conn_connect(account->server, account->port);
 294         if (!conn)
 295                 return 1;
 296         if (account->stls) {
 297                 if (pop3_res(line, sizeof(line)))
 298                         return 1;
 299                 pop3_cmd("STLS\r\n");
 300                 if (pop3_res(line, sizeof(line)))
 301                         return 1;
 302         }
 303         if (conn_tls(conn, account->cert)) {
 304                 conn_close(conn);
 305                 return 1;
 306         }
 307         buf_pos = 0;
 308         buf_len = 0;
 309         if (account->uidl)
 310                 uidl = uidl_read(account->uidl);
 311         printf("fetching %s@%s\n", account->user, account->server);
 312         if (!account->stls)
 313                 if (pop3_res(line, sizeof(line)))
 314                         return 1;
 315         if (pop3_login(account->user, account->pass))
 316                 return 1;
 317         if (pop3_stat())
 318                 return 1;
 319         if (account->uidl)
 320                 if (pop3_uidl())
 321                         return 1;
 322         batch = account->nopipe ? 1 : nmails;
 323         for (i = 0; i < nmails; i += batch)
 324                 if ((failed = fetch_mails(i, MIN(nmails, i + batch), account->del)))
 325                         break;
 326         if (!failed) {
 327                 pop3_cmd("QUIT\r\n");
 328                 pop3_get(line, sizeof(line));
 329         }
 330         conn_close(conn);
 331         if (uidl)
 332                 uidl_save(uidl);
 333         uidl = NULL;
 334         return failed;
 335 }
 336
 337 static void sigint(int sig)
 338 {
 339         if (uidl)
 340                 uidl_save(uidl);
 341         exit(1);
 342 }
 343
 344 int main(int argc, char *argv[])
 345 {
 346         int i;
 347         signal(SIGINT, sigint);
 348         mailbuf = malloc(MAXSIZE);
 349         for (i = 0; i < ARRAY_SIZE(accounts); i++)
 350                 fetch(&accounts[i]);
 351         free(mailbuf);
 352         return 0;
 353 }