--- /dev/null
+Implement double-bounce handling via an external program, controlled
+by the DBOUNCEPROG config parameter.
+
+--- a/conf.c
++++ b/conf.c
+@@ -233,6 +233,10 @@
+ if (data != NULL)
+ config->certfile = strdup(data);
+ }
++ else if (strcmp(word, "DBOUNCEPROG") == 0) {
++ if (data != NULL)
++ config->dbounceprog = strdup(data);
++ }
+ else if (strcmp(word, "VIRTUAL") == 0)
+ config->features |= VIRTUAL;
+ else if (strcmp(word, "STARTTLS") == 0)
+--- a/dma.8
++++ b/dma.8
+@@ -215,6 +215,26 @@
+ .Fl q
+ option.
+ This option is handy if you are behind a dialup line.
++.It Ic DBOUNCEPROG Xo
++(string, default=commented)
++.Xc
++Comment if you want the default behavior of
++.Nm
++upon double bounces - just abort the delivery.
++Otherwise, specify the name or full path to a program that will process
++the bounced bounce message.
++.Pp
++The program will be invoked with several command-line options:
++.Pp
++.Nm dbounce
++.Fl t
++.Ar dma
++.Fl a
++.Ar bounced@email.address
++.Fl i
++.Ar queueid
++.Fl f
++.Ar messagefile
+ .El
+ .Ss virtusertable
+ The
+--- a/dma.c
++++ b/dma.c
+@@ -443,12 +443,114 @@
+ struct qitem *bit;
+ char line[1000];
+ int error;
++ int pipefd[2];
++ pid_t child;
++ char *buf;
++ size_t i, pos, bufsize;
++ ssize_t n;
++ int stat;
++ struct sigaction sa;
+
+ /* Don't bounce bounced mails */
+ if (it->sender[0] == 0) {
+- syslog(LOG_CRIT, "%s: delivery panic: can't bounce a bounce",
++ syslog(LOG_ERR, "%s: bounce delivery failed, double-bouncing",
+ it->queueid);
+- exit(1);
++ if (config->dbounceprog == NULL) {
++ syslog(LOG_CRIT, "%s: delivery panic: can't bounce a bounce and no double-bounce program defined in the config file",
++ it->queueid);
++ exit(1);
++ }
++ if (pipe(pipefd) == -1) {
++ syslog(LOG_ERR, "%s: double-bounce: cannot pipe for the double-bounce program: %m",
++ it->queueid);
++ exit(1);
++ }
++ bzero(&sa, sizeof(sa));
++ sa.sa_flags = SA_NOCLDSTOP;
++ sa.sa_handler = SIG_DFL;
++ if (sigaction(SIGCHLD, &sa, NULL) == -1) {
++ syslog(LOG_ERR, "%s: double-bounce: cannot set signal action: %m",
++ it->queueid);
++ exit(1);
++ }
++ child = fork();
++ if (child == -1) {
++ syslog(LOG_ERR, "%s: double-bounce: cannot fork for the double-bounce program: %m",
++ it->queueid);
++ exit(1);
++ } else if (child == 0) {
++ close(pipefd[0]);
++ dup2(pipefd[1], STDIN_FILENO);
++ dup2(pipefd[1], STDOUT_FILENO);
++ dup2(pipefd[1], STDERR_FILENO);
++ execlp(config->dbounceprog, config->dbounceprog,
++ "-t", "dma", "-a", it->addr, "-i", it->queueid,
++ "-f", it->queuefn, NULL);
++ err(1, "Could not execute %s", config->dbounceprog);
++ /* NOTREACHED */
++ }
++
++ close(pipefd[1]);
++ buf = NULL;
++ pos = bufsize = 0;
++ while (1) {
++ if (pos == bufsize) {
++ char *nbuf;
++ size_t nsize;
++
++ nsize = bufsize + BUF_SIZE;
++ nbuf = realloc(buf, nsize);
++ if (nbuf == NULL) {
++ free(buf);
++ syslog(LOG_ERR, "%s: double-bounce failed: could not allocate %lu bytes of memory: %m", it->queueid, (unsigned long)nsize);
++ exit(1);
++ }
++ buf = nbuf;
++ bufsize = nsize;
++ }
++ n = read(pipefd[0], buf + pos, bufsize - pos);
++ if (n < 0) {
++ free(buf);
++ syslog(LOG_ERR, "%s: double-bounce failed: could not read the output of the double-bounce program: %m", it->queueid);
++ exit(1);
++ } else if (n == 0) {
++ break;
++ } else {
++ pos += n;
++ }
++ }
++ for (i = 0; i < pos; i++)
++ if (buf[i] < 32)
++ buf[i] = '_';
++ /*
++ * The order of the reallocation and reading above
++ * guarantees that we have at least one more byte available
++ * in buf[] after pos.
++ */
++ buf[pos] = '\0';
++
++ if (waitpid(child, &stat, 0) == -1) {
++ syslog(LOG_ERR, "%s: double-bounce deferred: could not fetch the result from child process %ld: %m; child process output: %s",
++ it->queueid, (long)child, buf);
++ exit(1);
++ } else if (WIFSIGNALED(stat)) {
++ syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld died from signal %d; child process output: %s",
++ it->queueid, child, WTERMSIG(stat), buf);
++ exit(1);
++ } else if (!WIFEXITED(stat)) {
++ syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld got an unexpected waitpid code of %d; child process output: %s",
++ it->queueid, child, stat, buf);
++ exit(1);
++ } else if (WEXITSTATUS(stat) != 0) {
++ syslog(LOG_ERR, "%s: double-bounce deferred: child process %ld exited with code %d; child process output: %s",
++ it->queueid, (long)child, (int)WEXITSTATUS(stat), buf);
++ exit(1);
++ }
++ syslog(LOG_ERR, "%s: double-bounce succeeded, message passed to handler `%s': %s",
++ it->queueid, config->dbounceprog, buf);
++ unlink(it->queuefn);
++ fclose(it->queuef);
++ exit(0);
+ }
+
+ syslog(LOG_ERR, "%s: delivery failed, bouncing",
+--- a/dma.h
++++ b/dma.h
+@@ -120,6 +120,7 @@
+ #ifdef HAVE_CRYPTO
+ SSL *ssl;
+ #endif /* HAVE_CRYPTO */
++ char *dbounceprog;
+ };
+
+
+--- a/etc/dma.conf
++++ b/etc/dma.conf
+@@ -40,3 +40,8 @@
+ # Uncomment if you want to defer your mails. This is useful if you are
+ # behind a dialup line. You have to submit your mails manually with dma -q
+ #DEFER
++
++# The double-bounce handler program. Leave this blank if you like dma's
++# default behavior of simply aborting the delivery, or specify the name or
++# full path to a program that will process the double-bounce message.
++#DBOUNCEPROG
projects / people / ms / dma.git / commitdiff
