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