listen on a port (postlicyd)
[apps/pfixtools.git] / main-postlicyd.c
index 6810bba..f9b96f5 100644 (file)
  * Copyright © 2006-2007 Pierre Habouzit
  */
 
-#include <signal.h>
-#include <time.h>
 #include <getopt.h>
 
+#include "buffer.h"
 #include "common.h"
+#include "threads.h"
+#include "tokens.h"
+
+#define DAEMON_NAME             "postlicyd"
+#define DEFAULT_PORT            10000
+#define RUNAS_USER              "nobody"
+#define RUNAS_GROUP             "nogroup"
+
+enum smtp_state {
+    SMTP_UNKNOWN,
+    SMTP_CONNECT,
+    SMTP_EHLO,
+    SMTP_HELO = SMTP_EHLO,
+    SMTP_MAIL,
+    SMTP_RCPT,
+    SMTP_DATA,
+    SMTP_END_OF_MESSAGE,
+    SMTP_VRFY,
+    SMTP_ETRN,
+};
+
+/* \see http://www.postfix.org/SMTPD_POLICY_README.html */
+typedef struct query_t {
+    unsigned state : 4;
+    unsigned esmtp : 1;
+
+    const char *helo_name;
+    const char *queue_id;
+    const char *sender;
+    const char *recipient;
+    const char *recipient_count;
+    const char *client_address;
+    const char *client_name;
+    const char *rclient_name;
+    const char *instance;
+
+    /* postfix 2.2+ */
+    const char *sasl_method;
+    const char *sasl_username;
+    const char *sasl_sender;
+    const char *size;
+    const char *ccert_subject;
+    const char *ccert_issuer;
+    const char *ccsert_fingerprint;
+
+    /* postfix 2.3+ */
+    const char *encryption_protocol;
+    const char *encryption_cipher;
+    const char *encryption_keysize;
+    const char *etrn_domain;
+} query_t;
+
+static int postfix_parsejob(query_t *query, char *p)
+{
+#define PARSE_CHECK(expr, error, ...)                                        \
+    do {                                                                     \
+        if (!(expr)) {                                                       \
+            syslog(LOG_ERR, error, ##__VA_ARGS__);                           \
+            return -1;                                                       \
+        }                                                                    \
+    } while (0)
+
+    p_clear(&query, 1);
+    while (p[0] != '\r' || p[1] != '\n') {
+        char *k, *v;
+        int klen, vlen, vtk;
+
+        while (isblank(*p))
+            p++;
+        p = strchr(k = p, '=');
+        PARSE_CHECK(p, "could not find '=' in line");
+        for (klen = p - k; klen && isblank(k[klen]); klen--);
+        p += 1; /* skip = */
+
+        while (isblank(*p))
+            p++;
+        p = strstr(v = p, "\r\n");
+        PARSE_CHECK(p, "could not find final \\r\\n in line");
+        for (vlen = p - v; vlen && isblank(v[vlen]); vlen--);
+        p += 2; /* skip \r\n */
+
+        vtk = tokenize(v, vlen);
+        switch (tokenize(k, klen)) {
+#define CASE(up, low)  case PTK_##up: query->low = v; v[vlen] = '\0'; break;
+            CASE(HELO_NAME,           helo_name);
+            CASE(QUEUE_ID,            queue_id);
+            CASE(SENDER,              sender);
+            CASE(RECIPIENT,           recipient);
+            CASE(RECIPIENT_COUNT,     recipient_count);
+            CASE(CLIENT_ADDRESS,      client_address);
+            CASE(CLIENT_NAME,         client_name);
+            CASE(RCLIENT_NAME,        rclient_name);
+            CASE(INSTANCE,            instance);
+            CASE(SASL_METHOD,         sasl_method);
+            CASE(SASL_USERNAME,       sasl_username);
+            CASE(SASL_SENDER,         sasl_sender);
+            CASE(SIZE,                size);
+            CASE(CCERT_SUBJECT,       ccert_subject);
+            CASE(CCERT_ISSUER,        ccert_issuer);
+            CASE(CCSERT_FINGERPRINT,  ccsert_fingerprint);
+            CASE(ENCRYPTION_PROTOCOL, encryption_protocol);
+            CASE(ENCRYPTION_CIPHER,   encryption_cipher);
+            CASE(ENCRYPTION_KEYSIZE,  encryption_keysize);
+            CASE(ETRN_DOMAIN,         etrn_domain);
+#undef CASE
+
+          case PTK_REQUEST:
+            PARSE_CHECK(vtk == PTK_SMTPD_ACCESS_POLICY,
+                        "unexpected `request' value: %.*s", vlen, v);
+            break;
+
+          case PTK_PROTOCOL_NAME:
+            PARSE_CHECK(vtk == PTK_SMTP || vtk == PTK_ESMTP,
+                        "unexpected `protocol_name' value: %.*s", vlen, v);
+            query->esmtp = vtk == PTK_ESMTP;
+            break;
+
+          case PTK_PROTOCOL_STATE:
+            switch (vtk) {
+#define CASE(name)  case PTK_##name: query->state = SMTP_##name; break;
+                CASE(CONNECT);
+                CASE(EHLO);
+                CASE(HELO);
+                CASE(MAIL);
+                CASE(RCPT);
+                CASE(DATA);
+                CASE(END_OF_MESSAGE);
+                CASE(VRFY);
+                CASE(ETRN);
+              default:
+                PARSE_CHECK(false, "unexpected `protocol_state` value: %.*s",
+                            vlen, v);
+#undef CASE
+            }
+            break;
+
+          default:
+            syslog(LOG_WARNING, "unexpected key, skipped: %.*s", klen, k);
+            break;
+        }
+    }
+
+    return query->state == SMTP_UNKNOWN ? -1 : 0;
+#undef PARSE_CHECK
+}
+
+static void *policy_run(int fd, void *data)
+{
+    buffer_t buf;
+
+    buffer_init(&buf);
+    for (;;) {
+        int nb = buffer_read(&buf, fd, -1);
+        const char *eoq;
+        query_t q;
+
+        if (nb < 0) {
+            if (errno == EAGAIN || errno == EINTR)
+                continue;
+            UNIXERR("read");
+            break;
+        }
+        if (nb == 0) {
+            if (buf.len)
+                syslog(LOG_ERR, "unexpected end of data");
+            break;
+        }
+
+        eoq = strstr(buf.data + MAX(0, buf.len - 3), "\r\n\r\n");
+        if (!eoq)
+            continue;
+
+        if (postfix_parsejob(&q, buf.data) < 0)
+            break;
+
+        buffer_consume(&buf, eoq + strlen("\r\n\r\n") - buf.data);
+        if (xwrite(fd, "DUNNO\r\n", strlen("DUNNO\r\n"))) {
+            UNIXERR("write");
+            break;
+        }
+    }
+    buffer_wipe(&buf);
+
+    close(fd);
+    return NULL;
+}
 
 /* administrivia {{{ */
 
@@ -60,49 +245,81 @@ static void main_shutdown(void)
 module_init(main_initialize);
 module_exit(main_shutdown);
 
-/* }}} */
-
-void *job_run(void *_fd)
+void usage(void)
 {
-    int fd = (intptr_t)_fd;
-
-    close(fd);
-    return NULL;
+    fputs("usage: "DAEMON_NAME" [options] config\n"
+          "\n"
+          "Options:\n"
+          "    -l <port>    port to listen to\n"
+          "    -p <pidfile> file to write our pid to\n"
+         , stderr);
 }
 
-static void main_loop(void)
+/* }}} */
+
+int main(int argc, char *argv[])
 {
+    struct sockaddr_in addr = {
+        .sin_family = AF_INET,
+        .sin_addr   = { htonl(INADDR_LOOPBACK) },
+    };
+    const char *pidfile = NULL;
+    int port = DEFAULT_PORT;
     int sock = -1;
 
+    for (int c = 0; (c = getopt(argc, argv, "h" "l:p:")) >= 0; ) {
+        switch (c) {
+          case 'p':
+            pidfile = optarg;
+            break;
+          case 'l':
+            port = atoi(optarg);
+            break;
+          default:
+            usage();
+            return EXIT_FAILURE;
+        }
+    }
+
+    if (argc - optind != 1) {
+        usage();
+        return EXIT_FAILURE;
+    }
+
+    if (pidfile_open(pidfile) < 0) {
+        syslog(LOG_CRIT, "unable to write pidfile %s", pidfile);
+        return EXIT_FAILURE;
+    }
+
+    if (drop_privileges(RUNAS_USER, RUNAS_GROUP) < 0) {
+        syslog(LOG_CRIT, "unable to drop privileges");
+        return EXIT_FAILURE;
+    }
+
+    if (daemon_detach() < 0) {
+        syslog(LOG_CRIT, "unable to fork");
+        return EXIT_FAILURE;
+    }
+
+    pidfile_refresh();
+
+    addr.sin_port = htons(port);
+    sock = tcp_listen((struct sockaddr *)&addr, sizeof(addr));
+    if (sock < 0)
+        return EXIT_FAILURE;
+
     while (!sigint) {
         int fd = accept(sock, NULL, 0);
-        pthread_attr_t attr;
-        pthread_t dummy;
-
         if (fd < 0) {
-            if (errno != EINTR || errno != EAGAIN)
+            if (errno != EINTR && errno != EAGAIN)
                 UNIXERR("accept");
             continue;
         }
-
-        pthread_attr_init(&attr);
-        pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
-        pthread_create(&dummy, &attr, job_run, (void *)(intptr_t)fd);
-        pthread_attr_destroy(&attr);
+        thread_launch(policy_run, fd, NULL);
+        threads_join();
     }
 
     close(sock);
-}
-
-int main(void)
-{
-    if (atexit(common_shutdown)) {
-        fputs("Cannot hook my atexit function, quitting !\n", stderr);
-        return EXIT_FAILURE;
-    }
-
-    common_initialize();
-    main_loop();
     syslog(LOG_INFO, "Stopping...");
     return EXIT_SUCCESS;
 }