pop3.c

   1 /*
   2  * pop3 - a simple pop3 mail client
   3  *
   4  * Copyright (C) 2010-2013 Ali Gholami Rudi
   5  *
   6  * This program is released under the modified BSD license.
   7  */
   8 #include <ctype.h>
   9 #include <errno.h>
  10 #include <fcntl.h>
  11 #include <netdb.h>
  12 #include <signal.h>
  13 #include <stdio.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <time.h>
  17 #include <unistd.h>
  18 #include "config.h"
  19 #include "uidl.h"
  20 #include "conn.h"
  21
  22 #define BUFFSIZE                (1 << 12)
  23 #define ARRAY_SIZE(a)           (sizeof(a) / sizeof((a)[0]))
  24 #define MIN(a, b)               ((a) < (b) ? (a) : (b))
  25 #define PRINT(s, l)             (write(1, (s), (l)))
  26
  27 static struct mailinfo {
  28         char name[1 << 4];
  29         char id[1 << 5];
  30         int size;
  31 } mails[MAXMAILS];
  32 static int nmails;
  33 static struct uidl *uidl;
  34
  35 static char buf[BUFFSIZE];
  36 static int buf_len;
  37 static int buf_pos;
  38 static struct conn *conn;
  39 static char *mailbuf;
  40
  41 static int pop3_read(void)
  42 {
  43         if (buf_pos == buf_len) {
  44                 buf_len = conn_read(conn, buf, sizeof(buf));
  45                 buf_pos = 0;
  46         }
  47         return buf_pos < buf_len ? (unsigned char) buf[buf_pos++] : -1;
  48 }
  49
  50 static int pop3_line(char *dst, int len)
  51 {
  52         int i = 0;
  53         int c;
  54         while (i < len) {
  55                 c = pop3_read();
  56                 if (c < 0)
  57                         return -1;
  58                 dst[i++] = c;
  59                 if (c == '\n')
  60                         break;
  61         }
  62         DPRINT(dst, i);
  63         return i;
  64 }
  65
  66 static void send_cmd(char *cmd)
  67 {
  68         conn_write(conn, cmd, strlen(cmd));
  69         DPRINT(cmd, strlen(cmd));
  70 }
  71
  72 static int is_eoc(char *line, int len)
  73 {
  74         return len >= 2 && len <= 3 && line[0] == '.' &&
  75                 (line[1] == '\r' || line[1] == '\n');
  76 }
  77
  78 static char *cutword(char *dst, char *s)
  79 {
  80         while (*s && isspace(*s))
  81                 s++;
  82         while (*s && !isspace(*s))
  83                 *dst++ = *s++;
  84         *dst = '\0';
  85         return s;
  86 }
  87
  88 static void login(char *user, char *pass)
  89 {
  90         char line[BUFFSIZE];
  91         sprintf(line, "USER %s\r\n", user);
  92         send_cmd(line);
  93         pop3_line(line, sizeof(line));
  94         sprintf(line, "PASS %s\r\n", pass);
  95         send_cmd(line);
  96         pop3_line(line, sizeof(line));
  97 }
  98
  99 static void mail_stat(void)
 100 {
 101         char line[BUFFSIZE];
 102         int len;
 103         send_cmd("STAT\r\n");
 104         len = pop3_line(line, sizeof(line));
 105         PRINT(line, len);
 106         send_cmd("LIST\r\n");
 107         len = pop3_line(line, sizeof(line));
 108         while ((len = pop3_line(line, sizeof(line))) != -1) {
 109                 struct mailinfo *mail;
 110                 char *s = line;
 111                 if (is_eoc(line, len))
 112                         break;
 113                 mail = &mails[nmails++];
 114                 s = cutword(mail->name, s);
 115                 mail->size = atoi(s);
 116         }
 117 }
 118
 119 static void mail_uidl(void)
 120 {
 121         char line[BUFFSIZE];
 122         char name[100];
 123         int len;
 124         int i = 0;
 125         send_cmd("UIDL\r\n");
 126         len = pop3_line(line, sizeof(line));
 127         while ((len = pop3_line(line, sizeof(line))) > 0 && !is_eoc(line, len)) {
 128                 char *s = line;
 129                 s = cutword(name, s);
 130                 s = cutword(mails[i++].id, s);
 131         }
 132 }
 133
 134 static void req_mail(int i)
 135 {
 136         char cmd[100];
 137         sprintf(cmd, "RETR %s\r\n", mails[i].name);
 138         send_cmd(cmd);
 139 }
 140
 141 static char *mail_dst(char *line, int len)
 142 {
 143         int i;
 144         line[len] = '\0';
 145         for (i = 0; i < ARRAY_SIZE(filters); i++) {
 146                 char *hdr = filters[i].hdr;
 147                 if (!strncmp(hdr, line, strlen(hdr)) &&
 148                                 strstr(line, filters[i].val))
 149                         return filters[i].dst;
 150         }
 151         return NULL;
 152 }
 153
 154 static int xwrite(int fd, char *buf, int len)
 155 {
 156         int nw = 0;
 157         while (nw < len) {
 158                 int ret = write(fd, buf + nw, len - nw);
 159                 if (ret == -1 && (errno == EAGAIN || errno == EINTR))
 160                         continue;
 161                 if (ret < 0)
 162                         break;
 163                 nw += ret;
 164         }
 165         return nw;
 166 }
 167
 168 static int mail_write(char *dst, char *mail, int len)
 169 {
 170         int fd = open(dst, O_WRONLY | O_APPEND | O_CREAT, 0600);
 171         if (fd == -1)
 172                 return -1;
 173         if (xwrite(fd, mail, len) != len)
 174                 return -1;
 175         close(fd);
 176         return 0;
 177 }
 178
 179 static char *putstr(char *dst, char *src)
 180 {
 181         int len = strchr(src, '\0') - src;
 182         memcpy(dst, src, len + 1);
 183         return dst + len;
 184 }
 185
 186 static char *put_from_(char *s)
 187 {
 188         time_t t;
 189         time(&t);
 190         s = putstr(s, "From ");
 191         s = putstr(s, getenv("USER") ? getenv("USER") : "root");
 192         s += strftime(s, MAXSIZE, " %a %b %d %H:%M:%S %Y\n", localtime(&t));
 193         return s;
 194 }
 195
 196 static int lone_from(char *s)
 197 {
 198         while (*s == '>')
 199                 s++;
 200         return !strncmp("From ", s, 5);
 201 }
 202
 203 static int ret_mail(int i)
 204 {
 205         char line[BUFFSIZE];
 206         char *s = mailbuf;
 207         int len = pop3_line(line, sizeof(line));
 208         char *dst = NULL;
 209         int hdr = 1;
 210         int ret;
 211         PRINT(mails[i].name, strlen(mails[i].name));
 212         s = put_from_(s);
 213         while (1) {
 214                 len = pop3_line(line, sizeof(line));
 215                 if (len <= 0)           /* end of stream or error */
 216                         return -1;
 217                 if (is_eoc(line, len))
 218                         break;
 219                 if (len > 1 && line[len - 2] == '\r')
 220                         line[len-- - 2] = '\n';
 221                 if (line[0] == '\n')
 222                         hdr = 0;
 223                 if (hdr && !dst)
 224                         dst = mail_dst(line, len);
 225                 if (lone_from(line))
 226                         *s++ = '>';
 227                 memcpy(s, line, len);
 228                 s += len;
 229         }
 230         *s++ = '\n';
 231         if (!dst)
 232                 dst = SPOOL;
 233         ret = mail_write(dst, mailbuf, s - mailbuf);
 234         sprintf(line, " -> %s\n", dst);
 235         PRINT(line, strlen(line));
 236         return ret;
 237 }
 238
 239 static void del_mail(int i)
 240 {
 241         char cmd[100];
 242         sprintf(cmd, "DELE %s\r\n", mails[i].name);
 243         send_cmd(cmd);
 244 }
 245
 246 static int size_ok(int i)
 247 {
 248         return mails[i].size + 100 < MAXSIZE;
 249 }
 250
 251 static int uidl_new(int i)
 252 {
 253         return !uidl || !uidl_find(uidl, mails[i].id);
 254 }
 255
 256 static int ret_mails(int beg, int end, int del)
 257 {
 258         char line[BUFFSIZE];
 259         int i;
 260         for (i = beg; i < end; i++)
 261                 if (size_ok(i) && uidl_new(i))
 262                         req_mail(i);
 263         for (i = beg; i < end; i++) {
 264                 if (size_ok(i) && uidl_new(i)) {
 265                         if (ret_mail(i) == -1)
 266                                 return -1;
 267                         if (uidl)
 268                                 uidl_add(uidl, mails[i].id);
 269                 }
 270         }
 271         if (del) {
 272                 for (i = beg; i < end; i++)
 273                         if ((!uidl && size_ok(i)) || (uidl && !uidl_new(i)))
 274                                 del_mail(i);
 275                 for (i = beg; i < end; i++)
 276                         if ((!uidl && size_ok(i)) || (uidl && !uidl_new(i)))
 277                                 pop3_line(line, sizeof(line));
 278         }
 279         return 0;
 280 }
 281
 282 static int fetch(struct account *account)
 283 {
 284         char line[BUFFSIZE];
 285         int batch;
 286         int i;
 287         nmails = 0;
 288         conn = conn_connect(account->server, account->port, account->cert);
 289         if (!conn)
 290                 return -1;
 291         buf_pos = 0;
 292         buf_len = 0;
 293         if (account->uidl)
 294                 uidl = uidl_read(account->uidl);
 295         sprintf(line, "fetching %s@%s\n", account->user, account->server);
 296         PRINT(line, strlen(line));
 297         pop3_line(line, sizeof(line));
 298         login(account->user, account->pass);
 299         mail_stat();
 300         if (account->uidl)
 301                 mail_uidl();
 302         batch = account->nopipe ? 1 : nmails;
 303         for (i = 0; i < nmails; i += batch)
 304                 ret_mails(i, MIN(nmails, i + batch), account->del);
 305         send_cmd("QUIT\r\n");
 306         pop3_line(line, sizeof(line));
 307         conn_close(conn);
 308         if (uidl)
 309                 uidl_save(uidl);
 310         uidl = NULL;
 311         return 0;
 312 }
 313
 314 static void sigint(int sig)
 315 {
 316         if (uidl)
 317                 uidl_save(uidl);
 318         exit(1);
 319 }
 320
 321 int main(int argc, char *argv[])
 322 {
 323         int i;
 324         signal(SIGINT, sigint);
 325         mailbuf = malloc(MAXSIZE);
 326         for (i = 0; i < ARRAY_SIZE(accounts); i++)
 327                 if (fetch(&accounts[i]) == -1)
 328                         return 1;
 329         free(mailbuf);
 330         return 0;
 331 }