postfix.c

   1 /******************************************************************************/
   2 /*          postlicyd: a postfix policy daemon with a lot of features         */
   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 <errno.h>
  37 #include <limits.h>
  38 #include <stdbool.h>
  39 #include <syslog.h>
  40 #include <unistd.h>
  41
  42 #include "job.h"
  43 #include "postfix.h"
  44 #include "buffer.h"
  45 #include "tokens.h"
  46
  47 #define ishspace(c)  ((c) == ' ' || (c) == '\t')
  48
  49 struct jpriv_t {
  50     buffer_t ibuf;
  51     buffer_t obuf;
  52     query_t query;
  53 };
  54
  55 static jpriv_t *postfix_jpriv_init(jpriv_t *jp)
  56 {
  57     buffer_init(&jp->ibuf);
  58     buffer_init(&jp->obuf);
  59     query_init(&jp->query);
  60     return jp;
  61 }
  62 static void postfix_jpriv_wipe(jpriv_t *jp)
  63 {
  64     query_wipe(&jp->query);
  65     buffer_wipe(&jp->ibuf);
  66     buffer_wipe(&jp->obuf);
  67 }
  68 DO_NEW(jpriv_t, postfix_jpriv);
  69 DO_DELETE(jpriv_t, postfix_jpriv);
  70
  71 static void postfix_stop(job_t *job)
  72 {
  73     postfix_jpriv_delete(&job->jdata);
  74 }
  75
  76 static int postfix_parsejob(query_t *query)
  77 {
  78 #define PARSE_CHECK(expr, error, ...)                                        \
  79     do {                                                                     \
  80         if (!(expr)) {                                                       \
  81             syslog(LOG_ERR, error, ##__VA_ARGS__);                           \
  82             return -1;                                                       \
  83         }                                                                    \
  84     } while (0)
  85
  86     char *p = vskipspaces(query->data.data);
  87
  88     while (*p) {
  89         char *k, *v;
  90         int klen, vlen, vtk;
  91
  92         while (ishspace(*p))
  93             p++;
  94         p = strchr(k = p, '=');
  95         PARSE_CHECK(p, "could not find '=' in line");
  96         for (klen = p - k; klen && ishspace(k[klen]); klen--);
  97         p += 1; /* skip = */
  98
  99         while (ishspace(*p))
 100             p++;
 101         p = strstr(v = p, "\r\n");
 102         PARSE_CHECK(p, "could not find final \\r\\n in line");
 103         for (vlen = p - v; vlen && ishspace(v[vlen]); vlen--);
 104         p += 2; /* skip \r\n */
 105
 106         vtk = tokenize(v, vlen);
 107         switch (tokenize(k, klen)) {
 108 #define CASE(up, low)  case PTK_##up: query->low = v; v[vlen] = '\0'; break;
 109             CASE(HELO_NAME,           helo_name);
 110             CASE(QUEUE_ID,            queue_id);
 111             CASE(SENDER,              sender);
 112             CASE(RECIPIENT,           recipient);
 113             CASE(RECIPIENT_COUNT,     recipient_count);
 114             CASE(CLIENT_ADDRESS,      client_address);
 115             CASE(CLIENT_NAME,         client_name);
 116             CASE(RCLIENT_NAME,        rclient_name);
 117             CASE(INSTANCE,            instance);
 118             CASE(SASL_METHOD,         sasl_method);
 119             CASE(SASL_USERNAME,       sasl_username);
 120             CASE(SASL_SENDER,         sasl_sender);
 121             CASE(SIZE,                size);
 122             CASE(CCERT_SUBJECT,       ccert_subject);
 123             CASE(CCERT_ISSUER,        ccert_issuer);
 124             CASE(CCSERT_FINGERPRINT,  ccsert_fingerprint);
 125             CASE(ENCRYPTION_PROTOCOL, encryption_protocol);
 126             CASE(ENCRYPTION_CIPHER,   encryption_cipher);
 127             CASE(ENCRYPTION_KEYSIZE,  encryption_keysize);
 128             CASE(ETRN_DOMAIN,         etrn_domain);
 129 #undef CASE
 130
 131           case PTK_REQUEST:
 132             PARSE_CHECK(vtk == PTK_SMTPD_ACCESS_POLICY,
 133                         "unexpected `request' value: %.*s", vlen, v);
 134             break;
 135
 136           case PTK_PROTOCOL_NAME:
 137             PARSE_CHECK(vtk == PTK_SMTP || vtk == PTK_ESMTP,
 138                         "unexpected `protocol_name' value: %.*s", vlen, v);
 139             query->esmtp = vtk == PTK_ESMTP;
 140             break;
 141
 142           case PTK_PROTOCOL_STATE:
 143             switch (vtk) {
 144 #define CASE(name)  case PTK_##name: query->state = SMTP_##name; break;
 145                 CASE(CONNECT);
 146                 CASE(EHLO);
 147                 CASE(HELO);
 148                 CASE(MAIL);
 149                 CASE(RCPT);
 150                 CASE(DATA);
 151                 CASE(END_OF_MESSAGE);
 152                 CASE(VRFY);
 153                 CASE(ETRN);
 154               default:
 155                 PARSE_CHECK(false, "unexpected `protocol_state` value: %.*s",
 156                             vlen, v);
 157 #undef CASE
 158             }
 159             break;
 160
 161           default:
 162             return -1;
 163         }
 164     }
 165
 166     return query->state == SMTP_UNKNOWN ? -1 : 0;
 167
 168 #undef PARSE_CHECK
 169 }
 170
 171 static void postfix_process(job_t *job)
 172 {
 173     int nb;
 174     const char *p;
 175
 176     switch (job->mode) {
 177       case JOB_LISTEN:
 178         if ((job = job_accept(job, JOB_READ))) {
 179             job->jdata   = postfix_jpriv_new();
 180             job->process = &postfix_process;
 181             job->stop    = &postfix_stop;
 182         }
 183         return;
 184
 185       case JOB_WRITE:
 186         nb = write(job->fd, job->jdata->obuf.data, job->jdata->obuf.len);
 187         if (nb < 0) {
 188             if ((job->error = errno != EINTR && errno != EAGAIN)) {
 189                 syslog(LOG_ERR, "unexpected problem on the socket: %m");
 190             }
 191             return;
 192         }
 193
 194         buffer_consume(&job->jdata->obuf, nb);
 195         if (job->jdata->obuf.len)
 196             return;
 197
 198         job_update_mode(job, JOB_READ);
 199
 200         /* fall through */
 201
 202       case JOB_READ:
 203         nb = buffer_read(&job->jdata->ibuf, job->fd, -1);
 204         if (nb < 0) {
 205             if ((job->error = errno != EINTR && errno != EAGAIN)) {
 206                 syslog(LOG_ERR, "unexpected problem on the socket: %m");
 207             }
 208             return;
 209         }
 210         if (nb == 0) {
 211             syslog(LOG_ERR, "unexpected eof");
 212             job->error = true;
 213             return;
 214         }
 215
 216         p = strstr(skipspaces(job->jdata->ibuf.data), "\r\n\r\n");
 217         if (!p) {
 218             if (job->jdata->ibuf.len > SHRT_MAX) {
 219                 syslog(LOG_ERR, "too much data without CRLFCRLF");
 220                 job->error = true;
 221             }
 222             return;
 223         }
 224         p += 4;
 225
 226         query_reset(&job->jdata->query);
 227         buffer_add(&job->jdata->query.data, job->jdata->ibuf.data,
 228                    p - 2 - job->jdata->ibuf.data);
 229         buffer_consume(&job->jdata->query.data, p - job->jdata->ibuf.data);
 230
 231         if (postfix_parsejob(&job->jdata->query) < 0) {
 232             job->error = true;
 233             return;
 234         }
 235
 236         job_update_mode(job, JOB_IDLE);
 237
 238         /* TODO: run the scenario */
 239         return;
 240
 241       default:
 242         job->error = true;
 243         return;
 244     }
 245 }