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
  88     buffer_t data;
  89 } query_t;
  90
  91 static query_t *query_init(query_t *rq) {
  92     memset(rq, 0, offsetof(query_t, data));
  93     buffer_init(&rq->data);
  94     return rq;
  95 }
  96 static void query_wipe(query_t *rq) {
  97     buffer_wipe(&rq->data);
  98 }
  99
 100 static int postfix_parsejob(query_t *query)
 101 {
 102 #define PARSE_CHECK(expr, error, ...)                                        \
 103     do {                                                                     \
 104         if (!(expr)) {                                                       \
 105             syslog(LOG_ERR, error, ##__VA_ARGS__);                           \
 106             return -1;                                                       \
 107         }                                                                    \
 108     } while (0)
 109
 110     char *p = vskipspaces(query->data.data);
 111
 112     memset(query, 0, offsetof(query_t, data));
 113     while (p[0] != '\r' || p[1] != '\n') {
 114         char *k, *v;
 115         int klen, vlen, vtk;
 116
 117         while (isblank(*p))
 118             p++;
 119         p = strchr(k = p, '=');
 120         PARSE_CHECK(p, "could not find '=' in line");
 121         for (klen = p - k; klen && isblank(k[klen]); klen--);
 122         p += 1; /* skip = */
 123
 124         while (isblank(*p))
 125             p++;
 126         p = strstr(v = p, "\r\n");
 127         PARSE_CHECK(p, "could not find final \\r\\n in line");
 128         for (vlen = p - v; vlen && isblank(v[vlen]); vlen--);
 129         p += 2; /* skip \r\n */
 130
 131         vtk = tokenize(v, vlen);
 132         switch (tokenize(k, klen)) {
 133 #define CASE(up, low)  case PTK_##up: query->low = v; v[vlen] = '\0'; break;
 134             CASE(HELO_NAME,           helo_name);
 135             CASE(QUEUE_ID,            queue_id);
 136             CASE(SENDER,              sender);
 137             CASE(RECIPIENT,           recipient);
 138             CASE(RECIPIENT_COUNT,     recipient_count);
 139             CASE(CLIENT_ADDRESS,      client_address);
 140             CASE(CLIENT_NAME,         client_name);
 141             CASE(RCLIENT_NAME,        rclient_name);
 142             CASE(INSTANCE,            instance);
 143             CASE(SASL_METHOD,         sasl_method);
 144             CASE(SASL_USERNAME,       sasl_username);
 145             CASE(SASL_SENDER,         sasl_sender);
 146             CASE(SIZE,                size);
 147             CASE(CCERT_SUBJECT,       ccert_subject);
 148             CASE(CCERT_ISSUER,        ccert_issuer);
 149             CASE(CCSERT_FINGERPRINT,  ccsert_fingerprint);
 150             CASE(ENCRYPTION_PROTOCOL, encryption_protocol);
 151             CASE(ENCRYPTION_CIPHER,   encryption_cipher);
 152             CASE(ENCRYPTION_KEYSIZE,  encryption_keysize);
 153             CASE(ETRN_DOMAIN,         etrn_domain);
 154 #undef CASE
 155
 156           case PTK_REQUEST:
 157             PARSE_CHECK(vtk == PTK_SMTPD_ACCESS_POLICY,
 158                         "unexpected `request' value: %.*s", vlen, v);
 159             break;
 160
 161           case PTK_PROTOCOL_NAME:
 162             PARSE_CHECK(vtk == PTK_SMTP || vtk == PTK_ESMTP,
 163                         "unexpected `protocol_name' value: %.*s", vlen, v);
 164             query->esmtp = vtk == PTK_ESMTP;
 165             break;
 166
 167           case PTK_PROTOCOL_STATE:
 168             switch (vtk) {
 169 #define CASE(name)  case PTK_##name: query->state = SMTP_##name; break;
 170                 CASE(CONNECT);
 171                 CASE(EHLO);
 172                 CASE(HELO);
 173                 CASE(MAIL);
 174                 CASE(RCPT);
 175                 CASE(DATA);
 176                 CASE(END_OF_MESSAGE);
 177                 CASE(VRFY);
 178                 CASE(ETRN);
 179               default:
 180                 PARSE_CHECK(false, "unexpected `protocol_state` value: %.*s",
 181                             vlen, v);
 182 #undef CASE
 183             }
 184             break;
 185
 186           default:
 187             syslog(LOG_WARNING, "unexpected key, skipped: %.*s", klen, k);
 188             break;
 189         }
 190     }
 191
 192     return query->state == SMTP_UNKNOWN ? -1 : 0;
 193 #undef PARSE_CHECK
 194 }
 195
 196 static void *policy_run(int fd, void *data)
 197 {
 198     query_t q;
 199     query_init(&q);
 200
 201     for (;;) {
 202         int nb = buffer_read(&q.data, fd, -1);
 203         const char *eoq;
 204
 205         if (nb < 0) {
 206             if (errno == EAGAIN || errno == EINTR)
 207                 continue;
 208             UNIXERR("read");
 209             break;
 210         }
 211         if (nb == 0) {
 212             if (q.data.len)
 213                 syslog(LOG_ERR, "unexpected end of data");
 214             break;
 215         }
 216
 217         eoq = strstr(q.data.data + MAX(0, q.data.len - 3), "\r\n\r\n");
 218         if (!eoq)
 219             continue;
 220
 221         if (postfix_parsejob(&q) < 0)
 222             break;
 223
 224         buffer_consume(&q.data, eoq + strlen("\r\n\r\n") - q.data.data);
 225         if (xwrite(fd, "DUNNO\r\n", strlen("DUNNO\r\n"))) {
 226             UNIXERR("write");
 227             break;
 228         }
 229     }
 230
 231     query_wipe(&q);
 232     close(fd);
 233     return NULL;
 234 }
 235
 236 static int main_loop(void)
 237 {
 238     int exitcode = EXIT_SUCCESS;
 239     int sock = -1;
 240
 241     while (!sigint) {
 242         int fd = accept(sock, NULL, 0);
 243         if (fd < 0) {
 244             if (errno != EINTR || errno != EAGAIN)
 245                 UNIXERR("accept");
 246             continue;
 247         }
 248
 249         thread_launch(policy_run, fd, NULL);
 250         threads_join();
 251     }
 252
 253     close(sock);
 254     return exitcode;
 255 }
 256
 257 /* administrivia {{{ */
 258
 259 static int main_initialize(void)
 260 {
 261     openlog("postlicyd", LOG_PID, LOG_MAIL);
 262     signal(SIGPIPE, SIG_IGN);
 263     signal(SIGINT,  &common_sighandler);
 264     signal(SIGTERM, &common_sighandler);
 265     signal(SIGSEGV, &common_sighandler);
 266     syslog(LOG_INFO, "Starting...");
 267     return 0;
 268 }
 269
 270 static void main_shutdown(void)
 271 {
 272     closelog();
 273 }
 274
 275 module_init(main_initialize);
 276 module_exit(main_shutdown);
 277
 278 void usage(void)
 279 {
 280     fputs("usage: "DAEMON_NAME" [options] config\n"
 281           "\n"
 282           "Options:\n"
 283           "    -p <pidfile> file to write our pid to\n"
 284          , stderr);
 285 }
 286
 287 /* }}} */
 288
 289 int main(int argc, char *argv[])
 290 {
 291     const char *pidfile = NULL;
 292     int res;
 293
 294     for (int c = 0; (c = getopt(argc, argv, "h" "p:")) >= 0; ) {
 295         switch (c) {
 296           case 'p':
 297             pidfile = optarg;
 298             break;
 299           default:
 300             usage();
 301             return EXIT_FAILURE;
 302         }
 303     }
 304
 305     if (argc - optind != 1) {
 306         usage();
 307         return EXIT_FAILURE;
 308     }
 309
 310     if (pidfile_open(pidfile) < 0) {
 311         syslog(LOG_CRIT, "unable to write pidfile %s", pidfile);
 312         return EXIT_FAILURE;
 313     }
 314
 315     if (daemon_detach() < 0) {
 316         syslog(LOG_CRIT, "unable to fork");
 317         return EXIT_FAILURE;
 318     }
 319
 320     pidfile_refresh();
 321     res = main_loop();
 322     syslog(LOG_INFO, "Stopping...");
 323     return res;
 324 }