main-postlicyd.c

   1 /******************************************************************************/
   2 /*          pfixtools: a collection of postfix related tools                  */
   3 /*          ~~~~~~~~~                                                         */
   4 /*  ________________________________________________________________________  */
   5 /*                                                                            */
   6 /*  Redistribution and use in source and binary forms, with or without        */
   7 /*  modification, are permitted provided that the following conditions        */
   8 /*  are met:                                                                  */
   9 /*                                                                            */
  10 /*  1. Redistributions of source code must retain the above copyright         */
  11 /*     notice, this list of conditions and the following disclaimer.          */
  12 /*  2. Redistributions in binary form must reproduce the above copyright      */
  13 /*     notice, this list of conditions and the following disclaimer in the    */
  14 /*     documentation and/or other materials provided with the distribution.   */
  15 /*  3. The names of its contributors may not be used to endorse or promote    */
  16 /*     products derived from this software without specific prior written     */
  17 /*     permission.                                                            */
  18 /*                                                                            */
  19 /*  THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND   */
  20 /*  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE     */
  21 /*  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR        */
  22 /*  PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS    */
  23 /*  BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR    */
  24 /*  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF      */
  25 /*  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS  */
  26 /*  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN   */
  27 /*  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)   */
  28 /*  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF    */
  29 /*  THE POSSIBILITY OF SUCH DAMAGE.                                           */
  30 /******************************************************************************/
  31
  32 /*
  33  * Copyright © 2006-2007 Pierre Habouzit
  34  */
  35
  36 #include <getopt.h>
  37
  38 #include "buffer.h"
  39 #include "common.h"
  40 #include "threads.h"
  41 #include "tokens.h"
  42
  43 #define DAEMON_NAME             "postlicyd"
  44
  45 enum smtp_state {
  46     SMTP_UNKNOWN,
  47     SMTP_CONNECT,
  48     SMTP_EHLO,
  49     SMTP_HELO = SMTP_EHLO,
  50     SMTP_MAIL,
  51     SMTP_RCPT,
  52     SMTP_DATA,
  53     SMTP_END_OF_MESSAGE,
  54     SMTP_VRFY,
  55     SMTP_ETRN,
  56 };
  57
  58 /* \see http://www.postfix.org/SMTPD_POLICY_README.html */
  59 typedef struct query_t {
  60     unsigned state : 4;
  61     unsigned esmtp : 1;
  62
  63     const char *helo_name;
  64     const char *queue_id;
  65     const char *sender;
  66     const char *recipient;
  67     const char *recipient_count;
  68     const char *client_address;
  69     const char *client_name;
  70     const char *rclient_name;
  71     const char *instance;
  72
  73     /* postfix 2.2+ */
  74     const char *sasl_method;
  75     const char *sasl_username;
  76     const char *sasl_sender;
  77     const char *size;
  78     const char *ccert_subject;
  79     const char *ccert_issuer;
  80     const char *ccsert_fingerprint;
  81
  82     /* postfix 2.3+ */
  83     const char *encryption_protocol;
  84     const char *encryption_cipher;
  85     const char *encryption_keysize;
  86     const char *etrn_domain;
  87 } query_t;
  88
  89 static int postfix_parsejob(query_t *query, char *p)
  90 {
  91 #define PARSE_CHECK(expr, error, ...)                                        \
  92     do {                                                                     \
  93         if (!(expr)) {                                                       \
  94             syslog(LOG_ERR, error, ##__VA_ARGS__);                           \
  95             return -1;                                                       \
  96         }                                                                    \
  97     } while (0)
  98
  99     p_clear(&query, 1);
 100     while (p[0] != '\r' || p[1] != '\n') {
 101         char *k, *v;
 102         int klen, vlen, vtk;
 103
 104         while (isblank(*p))
 105             p++;
 106         p = strchr(k = p, '=');
 107         PARSE_CHECK(p, "could not find '=' in line");
 108         for (klen = p - k; klen && isblank(k[klen]); klen--);
 109         p += 1; /* skip = */
 110
 111         while (isblank(*p))
 112             p++;
 113         p = strstr(v = p, "\r\n");
 114         PARSE_CHECK(p, "could not find final \\r\\n in line");
 115         for (vlen = p - v; vlen && isblank(v[vlen]); vlen--);
 116         p += 2; /* skip \r\n */
 117
 118         vtk = tokenize(v, vlen);
 119         switch (tokenize(k, klen)) {
 120 #define CASE(up, low)  case PTK_##up: query->low = v; v[vlen] = '\0'; break;
 121             CASE(HELO_NAME,           helo_name);
 122             CASE(QUEUE_ID,            queue_id);
 123             CASE(SENDER,              sender);
 124             CASE(RECIPIENT,           recipient);
 125             CASE(RECIPIENT_COUNT,     recipient_count);
 126             CASE(CLIENT_ADDRESS,      client_address);
 127             CASE(CLIENT_NAME,         client_name);
 128             CASE(RCLIENT_NAME,        rclient_name);
 129             CASE(INSTANCE,            instance);
 130             CASE(SASL_METHOD,         sasl_method);
 131             CASE(SASL_USERNAME,       sasl_username);
 132             CASE(SASL_SENDER,         sasl_sender);
 133             CASE(SIZE,                size);
 134             CASE(CCERT_SUBJECT,       ccert_subject);
 135             CASE(CCERT_ISSUER,        ccert_issuer);
 136             CASE(CCSERT_FINGERPRINT,  ccsert_fingerprint);
 137             CASE(ENCRYPTION_PROTOCOL, encryption_protocol);
 138             CASE(ENCRYPTION_CIPHER,   encryption_cipher);
 139             CASE(ENCRYPTION_KEYSIZE,  encryption_keysize);
 140             CASE(ETRN_DOMAIN,         etrn_domain);
 141 #undef CASE
 142
 143           case PTK_REQUEST:
 144             PARSE_CHECK(vtk == PTK_SMTPD_ACCESS_POLICY,
 145                         "unexpected `request' value: %.*s", vlen, v);
 146             break;
 147
 148           case PTK_PROTOCOL_NAME:
 149             PARSE_CHECK(vtk == PTK_SMTP || vtk == PTK_ESMTP,
 150                         "unexpected `protocol_name' value: %.*s", vlen, v);
 151             query->esmtp = vtk == PTK_ESMTP;
 152             break;
 153
 154           case PTK_PROTOCOL_STATE:
 155             switch (vtk) {
 156 #define CASE(name)  case PTK_##name: query->state = SMTP_##name; break;
 157                 CASE(CONNECT);
 158                 CASE(EHLO);
 159                 CASE(HELO);
 160                 CASE(MAIL);
 161                 CASE(RCPT);
 162                 CASE(DATA);
 163                 CASE(END_OF_MESSAGE);
 164                 CASE(VRFY);
 165                 CASE(ETRN);
 166               default:
 167                 PARSE_CHECK(false, "unexpected `protocol_state` value: %.*s",
 168                             vlen, v);
 169 #undef CASE
 170             }
 171             break;
 172
 173           default:
 174             syslog(LOG_WARNING, "unexpected key, skipped: %.*s", klen, k);
 175             break;
 176         }
 177     }
 178
 179     return query->state == SMTP_UNKNOWN ? -1 : 0;
 180 #undef PARSE_CHECK
 181 }
 182
 183 static void *policy_run(int fd, void *data)
 184 {
 185     buffer_t buf;
 186
 187     buffer_init(&buf);
 188     for (;;) {
 189         int nb = buffer_read(&buf, fd, -1);
 190         const char *eoq;
 191         query_t q;
 192
 193         if (nb < 0) {
 194             if (errno == EAGAIN || errno == EINTR)
 195                 continue;
 196             UNIXERR("read");
 197             break;
 198         }
 199         if (nb == 0) {
 200             if (buf.len)
 201                 syslog(LOG_ERR, "unexpected end of data");
 202             break;
 203         }
 204
 205         eoq = strstr(buf.data + MAX(0, buf.len - 3), "\r\n\r\n");
 206         if (!eoq)
 207             continue;
 208
 209         if (postfix_parsejob(&q, buf.data) < 0)
 210             break;
 211
 212         buffer_consume(&buf, eoq + strlen("\r\n\r\n") - buf.data);
 213         if (xwrite(fd, "DUNNO\r\n", strlen("DUNNO\r\n"))) {
 214             UNIXERR("write");
 215             break;
 216         }
 217     }
 218     buffer_wipe(&buf);
 219
 220     close(fd);
 221     return NULL;
 222 }
 223
 224 /* administrivia {{{ */
 225
 226 static int main_initialize(void)
 227 {
 228     openlog("postlicyd", LOG_PID, LOG_MAIL);
 229     signal(SIGPIPE, SIG_IGN);
 230     signal(SIGINT,  &common_sighandler);
 231     signal(SIGTERM, &common_sighandler);
 232     signal(SIGSEGV, &common_sighandler);
 233     syslog(LOG_INFO, "Starting...");
 234     return 0;
 235 }
 236
 237 static void main_shutdown(void)
 238 {
 239     closelog();
 240 }
 241
 242 module_init(main_initialize);
 243 module_exit(main_shutdown);
 244
 245 void usage(void)
 246 {
 247     fputs("usage: "DAEMON_NAME" [options] config\n"
 248           "\n"
 249           "Options:\n"
 250           "    -p <pidfile> file to write our pid to\n"
 251          , stderr);
 252 }
 253
 254 /* }}} */
 255
 256 int main(int argc, char *argv[])
 257 {
 258     const char *pidfile = NULL;
 259     int sock = -1;
 260
 261     for (int c = 0; (c = getopt(argc, argv, "h" "p:")) >= 0; ) {
 262         switch (c) {
 263           case 'p':
 264             pidfile = optarg;
 265             break;
 266           default:
 267             usage();
 268             return EXIT_FAILURE;
 269         }
 270     }
 271
 272     if (argc - optind != 1) {
 273         usage();
 274         return EXIT_FAILURE;
 275     }
 276
 277     if (pidfile_open(pidfile) < 0) {
 278         syslog(LOG_CRIT, "unable to write pidfile %s", pidfile);
 279         return EXIT_FAILURE;
 280     }
 281
 282     if (daemon_detach() < 0) {
 283         syslog(LOG_CRIT, "unable to fork");
 284         return EXIT_FAILURE;
 285     }
 286
 287     pidfile_refresh();
 288
 289     while (!sigint) {
 290         int fd = accept(sock, NULL, 0);
 291         if (fd < 0) {
 292             if (errno != EINTR && errno != EAGAIN)
 293                 UNIXERR("accept");
 294             continue;
 295         }
 296         thread_launch(policy_run, fd, NULL);
 297         threads_join();
 298     }
 299
 300     close(sock);
 301     syslog(LOG_INFO, "Stopping...");
 302     return EXIT_SUCCESS;
 303 }