access config files at CONF_PATH, add makefile target to install conf files

[people/ms/dma.git] / dma.c

diff --git a/dma.c b/dma.c
index 61cae6839c944b54cb09cf7f691116d16544f9d1..3b1aeb1eac88f7ee2edcf919d98caff6c0cefb84 100644 (file)
--- a/dma.c
+++ b/dma.c
@@ -64,24 +64,33 @@ static void deliver(struct qitem *);
 struct aliases aliases = LIST_HEAD_INITIALIZER(aliases);
 struct strlist tmpfs = SLIST_HEAD_INITIALIZER(tmpfs);
 struct authusers authusers = LIST_HEAD_INITIALIZER(authusers);
-const char *username;
+char username[USERNAME_SIZE];
+uid_t useruid;
 const char *logident_base;
+char errmsg[ERRMSG_SIZE];
 
 static int daemonize = 1;
 
 struct config config = {
        .smarthost      = NULL,
        .port           = 25,
-       .aliases        = "/var/mail/aliases",
+       .aliases        = "/etc/aliases",
        .spooldir       = "/var/spool/dma",
        .authpath       = NULL,
        .certfile       = NULL,
        .features       = 0,
        .mailname       = NULL,
-       .mailnamefile   = NULL,
+       .masquerade_host = NULL,
+       .masquerade_user = NULL,
 };
 
 
+static void
+sighup_handler(int signo)
+{
+       (void)signo;    /* so that gcc doesn't complain */
+}
+
 static char *
 set_from(struct queue *queue, const char *osender)
 {
@@ -96,7 +105,14 @@ set_from(struct queue *queue, const char *osender)
                if (sender == NULL)
                        return (NULL);
        } else {
-               if (asprintf(&sender, "%s@%s", username, hostname()) <= 0)
+               const char *from_user = username;
+               const char *from_host = hostname();
+
+               if (config.masquerade_user)
+                       from_user = config.masquerade_user;
+               if (config.masquerade_host)
+                       from_host = config.masquerade_host;
+               if (asprintf(&sender, "%s@%s", from_user, from_host) <= 0)
                        return (NULL);
        }
 
@@ -105,7 +121,6 @@ set_from(struct queue *queue, const char *osender)
                return (NULL);
        }
 
-out:
        queue->sender = sender;
        return (sender);
 }
@@ -211,7 +226,6 @@ go_background(struct queue *queue)
        daemonize = 0;
 
        bzero(&sa, sizeof(sa));
-       sa.sa_flags = SA_NOCLDWAIT;
        sa.sa_handler = SIG_IGN;
        sigaction(SIGCHLD, &sa, NULL);
 
@@ -264,17 +278,18 @@ deliver(struct qitem *it)
 {
        int error;
        unsigned int backoff = MIN_RETRY;
-       const char *errmsg = "unknown bounce reason";
        struct timeval now;
        struct stat st;
 
+       snprintf(errmsg, sizeof(errmsg), "unknown bounce reason");
+
 retry:
        syslog(LOG_INFO, "trying delivery");
 
        if (it->remote)
-               error = deliver_remote(it, &errmsg);
+               error = deliver_remote(it);
        else
-               error = deliver_local(it, &errmsg);
+               error = deliver_local(it);
 
        switch (error) {
        case 0:
@@ -289,15 +304,17 @@ retry:
                }
                if (gettimeofday(&now, NULL) == 0 &&
                    (now.tv_sec - st.st_mtim.tv_sec > MAX_TIMEOUT)) {
-                       asprintf(__DECONST(void *, &errmsg),
+                       snprintf(errmsg, sizeof(errmsg),
                                 "Could not deliver for the last %d seconds. Giving up.",
                                 MAX_TIMEOUT);
                        goto bounce;
                }
-               sleep(backoff);
-               backoff *= 2;
-               if (backoff > MAX_RETRY)
-                       backoff = MAX_RETRY;
+               if (sleep(backoff) == 0) {
+                       /* pick the next backoff between [1.5, 2.5) times backoff */
+                       backoff = backoff + backoff / 2 + random() % backoff;
+                       if (backoff > MAX_RETRY)
+                               backoff = MAX_RETRY;
+               }
                goto retry;
 
        case -1:
@@ -358,12 +375,33 @@ show_queue(struct queue *queue)
 int
 main(int argc, char **argv)
 {
+       struct sigaction act;
        char *sender = NULL;
        struct queue queue;
        int i, ch;
        int nodot = 0, doqueue = 0, showq = 0, queue_only = 0;
        int recp_from_header = 0;
 
+       set_username();
+
+       /*
+        * We never run as root.  If called by root, drop permissions
+        * to the mail user.
+        */
+       if (geteuid() == 0 || getuid() == 0) {
+               struct passwd *pw;
+
+               pw = getpwnam(DMA_ROOT_USER);
+               if (pw == NULL)
+                       err(1, "cannot drop root privileges");
+
+               if (setuid(pw->pw_uid) != 0)
+                       err(1, "cannot drop root privileges");
+
+               if (geteuid() == 0 || getuid() == 0)
+                       errx(1, "cannot drop root privileges");
+       }
+
        atexit(deltmp);
        init_random();
 
@@ -468,11 +506,14 @@ skipopts:
        if (logident_base == NULL)
                logident_base = "dma";
        setlogident(NULL);
-       set_username();
 
-       /* XXX fork root here */
+       act.sa_handler = sighup_handler;
+       act.sa_flags = 0;
+       sigemptyset(&act.sa_mask);
+       if (sigaction(SIGHUP, &act, NULL) != 0)
+               syslog(LOG_WARNING, "can not set signal handler: %m");
 
-       parse_conf(CONF_PATH);
+       parse_conf(CONF_PATH "/dma.conf");
 
        if (config.authpath != NULL)
                parse_authfile(config.authpath);