s3:unix_msg: add fds-array to unix_msg_send() for fd passing

Pair-Programmed-With: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Michael Adam <obnox@samba.org>

5 files changed, 39 insertions, 14 deletions

diff --git a/source3/lib/messages_dgm.c b/source3/lib/messages_dgm.c
index cadcb4be72..7ba79fcfd0 100644
--- a/source3/lib/messages_dgm.c
+++ b/source3/lib/messages_dgm.c
@@ -318,7 +318,7 @@ int messaging_dgm_send(pid_t pid, const struct iovec *iov, int iovlen)
 
 	DEBUG(10, ("%s: Sending message to %u\n", __func__, (unsigned)pid));
 
-	ret = unix_msg_send(ctx->dgm_ctx, &dst, iov, iovlen);
+	ret = unix_msg_send(ctx->dgm_ctx, &dst, iov, iovlen, NULL, 0);
 
 	return ret;
 }
diff --git a/source3/lib/unix_msg/test_source.c b/source3/lib/unix_msg/test_source.c
index 7f6a7a5e8c..5224ebff6f 100644
--- a/source3/lib/unix_msg/test_source.c
+++ b/source3/lib/unix_msg/test_source.c
@@ -65,7 +65,7 @@ int main(int argc, const char *argv[])
 		unsigned j;
 
 		for (j=0; j<100000; j++) {
-			ret = unix_msg_send(ctxs[i], &dst, &iov, 1);
+			ret = unix_msg_send(ctxs[i], &dst, &iov, 1, NULL, 0);
 			if (ret != 0) {
 				fprintf(stderr, "unix_msg_send failed: %s\n",
 					strerror(ret));
diff --git a/source3/lib/unix_msg/tests.c b/source3/lib/unix_msg/tests.c
index a213cc22a6..df094afb3d 100644
--- a/source3/lib/unix_msg/tests.c
+++ b/source3/lib/unix_msg/tests.c
@@ -103,7 +103,7 @@ int main(void)
 	state.buf = NULL;
 	state.buflen = 0;
 
-	ret = unix_msg_send(ctx1, &addr2, NULL, 0);
+	ret = unix_msg_send(ctx1, &addr2, NULL, 0, NULL, 0);
 	if (ret != 0) {
 		fprintf(stderr, "unix_msg_send failed: %s\n",
 			strerror(ret));
@@ -120,7 +120,7 @@ int main(void)
 	state.buf = &msg;
 	state.buflen = sizeof(msg);
 
-	ret = unix_msg_send(ctx1, &addr2, &iov, 1);
+	ret = unix_msg_send(ctx1, &addr2, &iov, 1, NULL, 0);
 	if (ret != 0) {
 		fprintf(stderr, "unix_msg_send failed: %s\n",
 			strerror(ret));
@@ -141,13 +141,13 @@ int main(void)
 	state.buflen = sizeof(buf);
 
 	for (i=0; i<3; i++) {
-		ret = unix_msg_send(ctx1, &addr2, &iov, 1);
+		ret = unix_msg_send(ctx1, &addr2, &iov, 1, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_send failed: %s\n",
 				strerror(ret));
 			return 1;
 		}
-		ret = unix_msg_send(ctx2, &addr2, &iov, 1);
+		ret = unix_msg_send(ctx2, &addr2, &iov, 1, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_send failed: %s\n",
 				strerror(ret));
@@ -186,7 +186,7 @@ int main(void)
 			j++;
 		}
 
-		ret = unix_msg_send(ctx1, &addr1, iovs, j);
+		ret = unix_msg_send(ctx1, &addr1, iovs, j, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_send failed: %s\n",
 				strerror(ret));
@@ -199,13 +199,13 @@ int main(void)
 	printf("Filling send queues before freeing\n");
 
 	for (i=0; i<5; i++) {
-		ret = unix_msg_send(ctx1, &addr2, &iov, 1);
+		ret = unix_msg_send(ctx1, &addr2, &iov, 1, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_send failed: %s\n",
 				strerror(ret));
 			return 1;
 		}
-		ret = unix_msg_send(ctx1, &addr1, &iov, 1);
+		ret = unix_msg_send(ctx1, &addr1, &iov, 1, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "unix_msg_send failed: %s\n",
 				strerror(ret));
diff --git a/source3/lib/unix_msg/unix_msg.c b/source3/lib/unix_msg/unix_msg.c
index e32a4d80bc..28ea51444c 100644
--- a/source3/lib/unix_msg/unix_msg.c
+++ b/source3/lib/unix_msg/unix_msg.c
@@ -851,7 +851,8 @@ int unix_msg_init(const struct sockaddr_un *addr,
 }
 
 int unix_msg_send(struct unix_msg_ctx *ctx, const struct sockaddr_un *dst,
-		  const struct iovec *iov, int iovlen)
+		  const struct iovec *iov, int iovlen,
+		  const int *fds, size_t num_fds)
 {
 	ssize_t msglen;
 	size_t sent;
@@ -869,6 +870,16 @@ int unix_msg_send(struct unix_msg_ctx *ctx, const struct sockaddr_un *dst,
 		return EINVAL;
 	}
 
+#ifndef HAVE_STRUCT_MSGHDR_MSG_CONTROL
+	if (num_fds > 0) {
+		return ENOSYS;
+	}
+#endif /* ! HAVE_STRUCT_MSGHDR_MSG_CONTROL */
+
+	if (num_fds > INT8_MAX) {
+		return EINVAL;
+	}
+
 	if (msglen <= (ctx->fragment_len - sizeof(uint64_t))) {
 		uint64_t cookie = 0;
 
@@ -880,7 +891,7 @@ int unix_msg_send(struct unix_msg_ctx *ctx, const struct sockaddr_un *dst,
 		}
 
 		return unix_dgram_send(ctx->dgram, dst, iov_copy, iovlen+1,
-				       NULL, 0);
+				       fds, num_fds);
 	}
 
 	hdr = (struct unix_msg_hdr) {
@@ -936,8 +947,19 @@ int unix_msg_send(struct unix_msg_ctx *ctx, const struct sockaddr_un *dst,
 		}
 		sent += (fragment_len - sizeof(ctx->cookie) - sizeof(hdr));
 
-		ret = unix_dgram_send(ctx->dgram, dst, iov_copy, iov_index,
-				      NULL, 0);
+		/*
+		 * only the last fragment should pass the fd array.
+		 * That simplifies the receiver a lot.
+		 */
+		if (sent < msglen) {
+			ret = unix_dgram_send(ctx->dgram, dst,
+					      iov_copy, iov_index,
+					      NULL, 0);
+		} else {
+			ret = unix_dgram_send(ctx->dgram, dst,
+					      iov_copy, iov_index,
+					      fds, num_fds);
+		}
 		if (ret != 0) {
 			break;
 		}
diff --git a/source3/lib/unix_msg/unix_msg.h b/source3/lib/unix_msg/unix_msg.h
index 16c7c83aaa..6024804fc3 100644
--- a/source3/lib/unix_msg/unix_msg.h
+++ b/source3/lib/unix_msg/unix_msg.h
@@ -93,11 +93,14 @@ int unix_msg_init(const struct sockaddr_un *addr,
  * @param[in] dst_sock The destination socket path
  * @param[in] iov The message
  * @param[in] iovlen The number of iov structs
+ * @param[in] fds - optional fd array
+ * @param[in] num_fds - fd array size
  * @return 0 on success, errno on failure
  */
 
 int unix_msg_send(struct unix_msg_ctx *ctx, const struct sockaddr_un *dst,
-		  const struct iovec *iov, int iovlen);
+		  const struct iovec *iov, int iovlen,
+		  const int *fds, size_t num_fds);
 
 /**
  * @brief Free a unix_msg_ctx