af_unix: Add OOB support

This patch adds OOB support for AF_UNIX sockets.
The semantics is same as TCP.

The last byte of a message with the OOB flag is
treated as the OOB byte. The byte is separated into
a skb and a pointer to the skb is stored in unix_sock.
The pointer is used to enforce OOB semantics.

Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 443 insertions, 0 deletions

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index fb010a35d61a..da9e8b699e42 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -38,6 +38,7 @@ TARGETS += mount_setattr
 TARGETS += mqueue
 TARGETS += nci
 TARGETS += net
+TARGETS += net/af_unix
 TARGETS += net/forwarding
 TARGETS += net/mptcp
 TARGETS += netfilter
diff --git a/tools/testing/selftests/net/af_unix/Makefile b/tools/testing/selftests/net/af_unix/Makefile
new file mode 100644
index 000000000000..cfc7f4f97fd1
--- /dev/null
+++ b/tools/testing/selftests/net/af_unix/Makefile
@@ -0,0 +1,5 @@
+##TEST_GEN_FILES := test_unix_oob
+TEST_PROGS := test_unix_oob
+include ../../lib.mk
+
+all: $(TEST_PROGS)
diff --git a/tools/testing/selftests/net/af_unix/test_unix_oob.c b/tools/testing/selftests/net/af_unix/test_unix_oob.c
new file mode 100644
index 000000000000..0f3e3763f4f8
--- /dev/null
+++ b/tools/testing/selftests/net/af_unix/test_unix_oob.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <errno.h>
+#include <netinet/tcp.h>
+#include <sys/un.h>
+#include <sys/signal.h>
+#include <sys/poll.h>
+
+static int pipefd[2];
+static int signal_recvd;
+static pid_t producer_id;
+static char sock_name[32];
+
+static void sig_hand(int sn, siginfo_t *si, void *p)
+{
+	signal_recvd = sn;
+}
+
+static int set_sig_handler(int signal)
+{
+	struct sigaction sa;
+
+	sa.sa_sigaction = sig_hand;
+	sigemptyset(&sa.sa_mask);
+	sa.sa_flags = SA_SIGINFO | SA_RESTART;
+
+	return sigaction(signal, &sa, NULL);
+}
+
+static void set_filemode(int fd, int set)
+{
+	int flags = fcntl(fd, F_GETFL, 0);
+
+	if (set)
+		flags &= ~O_NONBLOCK;
+	else
+		flags |= O_NONBLOCK;
+	fcntl(fd, F_SETFL, flags);
+}
+
+static void signal_producer(int fd)
+{
+	char cmd;
+
+	cmd = 'S';
+	write(fd, &cmd, sizeof(cmd));
+}
+
+static void wait_for_signal(int fd)
+{
+	char buf[5];
+
+	read(fd, buf, 5);
+}
+
+static void die(int status)
+{
+	fflush(NULL);
+	unlink(sock_name);
+	kill(producer_id, SIGTERM);
+	exit(status);
+}
+
+int is_sioctatmark(int fd)
+{
+	int ans = -1;
+
+	if (ioctl(fd, SIOCATMARK, &ans, sizeof(ans)) < 0) {
+#ifdef DEBUG
+		perror("SIOCATMARK Failed");
+#endif
+	}
+	return ans;
+}
+
+void read_oob(int fd, char *c)
+{
+
+	*c = ' ';
+	if (recv(fd, c, sizeof(*c), MSG_OOB) < 0) {
+#ifdef DEBUG
+		perror("Reading MSG_OOB Failed");
+#endif
+	}
+}
+
+int read_data(int pfd, char *buf, int size)
+{
+	int len = 0;
+
+	memset(buf, size, '0');
+	len = read(pfd, buf, size);
+#ifdef DEBUG
+	if (len < 0)
+		perror("read failed");
+#endif
+	return len;
+}
+
+static void wait_for_data(int pfd, int event)
+{
+	struct pollfd pfds[1];
+
+	pfds[0].fd = pfd;
+	pfds[0].events = event;
+	poll(pfds, 1, -1);
+}
+
+void producer(struct sockaddr_un *consumer_addr)
+{
+	int cfd;
+	char buf[64];
+	int i;
+
+	memset(buf, 'x', sizeof(buf));
+	cfd = socket(AF_UNIX, SOCK_STREAM, 0);
+
+	wait_for_signal(pipefd[0]);
+	if (connect(cfd, (struct sockaddr *)consumer_addr,
+		     sizeof(struct sockaddr)) != 0) {
+		perror("Connect failed");
+		kill(0, SIGTERM);
+		exit(1);
+	}
+
+	for (i = 0; i < 2; i++) {
+		/* Test 1: Test for SIGURG and OOB */
+		wait_for_signal(pipefd[0]);
+		memset(buf, 'x', sizeof(buf));
+		buf[63] = '@';
+		send(cfd, buf, sizeof(buf), MSG_OOB);
+
+		wait_for_signal(pipefd[0]);
+
+		/* Test 2: Test for OOB being overwitten */
+		memset(buf, 'x', sizeof(buf));
+		buf[63] = '%';
+		send(cfd, buf, sizeof(buf), MSG_OOB);
+
+		memset(buf, 'x', sizeof(buf));
+		buf[63] = '#';
+		send(cfd, buf, sizeof(buf), MSG_OOB);
+
+		wait_for_signal(pipefd[0]);
+
+		/* Test 3: Test for SIOCATMARK */
+		memset(buf, 'x', sizeof(buf));
+		buf[63] = '@';
+		send(cfd, buf, sizeof(buf), MSG_OOB);
+
+		memset(buf, 'x', sizeof(buf));
+		buf[63] = '%';
+		send(cfd, buf, sizeof(buf), MSG_OOB);
+
+		memset(buf, 'x', sizeof(buf));
+		send(cfd, buf, sizeof(buf), 0);
+
+		wait_for_signal(pipefd[0]);
+
+		/* Test 4: Test for 1byte OOB msg */
+		memset(buf, 'x', sizeof(buf));
+		buf[0] = '@';
+		send(cfd, buf, 1, MSG_OOB);
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	int lfd, pfd;
+	struct sockaddr_un consumer_addr, paddr;
+	socklen_t len = sizeof(consumer_addr);
+	char buf[1024];
+	int on = 0;
+	char oob;
+	int flags;
+	int atmark;
+	char *tmp_file;
+
+	lfd = socket(AF_UNIX, SOCK_STREAM, 0);
+	memset(&consumer_addr, 0, sizeof(consumer_addr));
+	consumer_addr.sun_family = AF_UNIX;
+	sprintf(sock_name, "unix_oob_%d", getpid());
+	unlink(sock_name);
+	strcpy(consumer_addr.sun_path, sock_name);
+
+	if ((bind(lfd, (struct sockaddr *)&consumer_addr,
+		  sizeof(consumer_addr))) != 0) {
+		perror("socket bind failed");
+		exit(1);
+	}
+
+	pipe(pipefd);
+
+	listen(lfd, 1);
+
+	producer_id = fork();
+	if (producer_id == 0) {
+		producer(&consumer_addr);
+		exit(0);
+	}
+
+	set_sig_handler(SIGURG);
+	signal_producer(pipefd[1]);
+
+	pfd = accept(lfd, (struct sockaddr *) &paddr, &len);
+	fcntl(pfd, F_SETOWN, getpid());
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 1:
+	 * veriyf that SIGURG is
+	 * delivered and 63 bytes are
+	 * read and oob is '@'
+	 */
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	read_oob(pfd, &oob);
+	len = read_data(pfd, buf, 1024);
+	if (!signal_recvd || len != 63 || oob != '@') {
+		fprintf(stderr, "Test 1 failed sigurg %d len %d %c\n",
+			 signal_recvd, len, oob);
+			die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 2:
+	 * Verify that the first OOB is over written by
+	 * the 2nd one and the first OOB is returned as
+	 * part of the read, and sigurg is received.
+	 */
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	len = 0;
+	while (len < 70)
+		len = recv(pfd, buf, 1024, MSG_PEEK);
+	len = read_data(pfd, buf, 1024);
+	read_oob(pfd, &oob);
+	if (!signal_recvd || len != 127 || oob != '#') {
+		fprintf(stderr, "Test 2 failed, sigurg %d len %d OOB %c\n",
+		signal_recvd, len, oob);
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 3:
+	 * verify that 2nd oob over writes
+	 * the first one and read breaks at
+	 * oob boundary returning 127 bytes
+	 * and sigurg is received and atmark
+	 * is set.
+	 * oob is '%' and second read returns
+	 * 64 bytes.
+	 */
+	len = 0;
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	while (len < 150)
+		len = recv(pfd, buf, 1024, MSG_PEEK);
+	len = read_data(pfd, buf, 1024);
+	atmark = is_sioctatmark(pfd);
+	read_oob(pfd, &oob);
+
+	if (!signal_recvd || len != 127 || oob != '%' || atmark != 1) {
+		fprintf(stderr, "Test 3 failed, sigurg %d len %d OOB %c ",
+		"atmark %d\n", signal_recvd, len, oob, atmark);
+		die(1);
+	}
+
+	signal_recvd = 0;
+
+	len = read_data(pfd, buf, 1024);
+	if (len != 64) {
+		fprintf(stderr, "Test 3.1 failed, sigurg %d len %d OOB %c\n",
+			signal_recvd, len, oob);
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 4:
+	 * verify that a single byte
+	 * oob message is delivered.
+	 * set non blocking mode and
+	 * check proper error is
+	 * returned and sigurg is
+	 * received and correct
+	 * oob is read.
+	 */
+
+	set_filemode(pfd, 0);
+
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	len = read_data(pfd, buf, 1024);
+	if ((len == -1) && (errno == 11))
+		len = 0;
+
+	read_oob(pfd, &oob);
+
+	if (!signal_recvd || len != 0 || oob != '@') {
+		fprintf(stderr, "Test 4 failed, sigurg %d len %d OOB %c\n",
+			 signal_recvd, len, oob);
+		die(1);
+	}
+
+	set_filemode(pfd, 1);
+
+	/* Inline Testing */
+
+	on = 1;
+	if (setsockopt(pfd, SOL_SOCKET, SO_OOBINLINE, &on, sizeof(on))) {
+		perror("SO_OOBINLINE");
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 1 -- Inline:
+	 * Check that SIGURG is
+	 * delivered and 63 bytes are
+	 * read and oob is '@'
+	 */
+
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	len = read_data(pfd, buf, 1024);
+
+	if (!signal_recvd || len != 63) {
+		fprintf(stderr, "Test 1 Inline failed, sigurg %d len %d\n",
+			signal_recvd, len);
+		die(1);
+	}
+
+	len = read_data(pfd, buf, 1024);
+
+	if (len != 1) {
+		fprintf(stderr,
+			 "Test 1.1 Inline failed, sigurg %d len %d oob %c\n",
+			 signal_recvd, len, oob);
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 2 -- Inline:
+	 * Verify that the first OOB is over written by
+	 * the 2nd one and read breaks correctly on
+	 * 2nd OOB boundary with the first OOB returned as
+	 * part of the read, and sigurg is delivered and
+	 * siocatmark returns true.
+	 * next read returns one byte, the oob byte
+	 * and siocatmark returns false.
+	 */
+	len = 0;
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	while (len < 70)
+		len = recv(pfd, buf, 1024, MSG_PEEK);
+	len = read_data(pfd, buf, 1024);
+	atmark = is_sioctatmark(pfd);
+	if (len != 127 || atmark != 1 || !signal_recvd) {
+		fprintf(stderr, "Test 2 Inline failed, len %d atmark %d\n",
+			 len, atmark);
+		die(1);
+	}
+
+	len = read_data(pfd, buf, 1024);
+	atmark = is_sioctatmark(pfd);
+	if (len != 1 || buf[0] != '#' || atmark == 1) {
+		fprintf(stderr, "Test 2.1 Inline failed, len %d data %c atmark %d\n",
+			len, buf[0], atmark);
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 3 -- Inline:
+	 * verify that 2nd oob over writes
+	 * the first one and read breaks at
+	 * oob boundary returning 127 bytes
+	 * and sigurg is received and siocatmark
+	 * is true after the read.
+	 * subsequent read returns 65 bytes
+	 * because of oob which should be '%'.
+	 */
+	len = 0;
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	while (len < 126)
+		len = recv(pfd, buf, 1024, MSG_PEEK);
+	len = read_data(pfd, buf, 1024);
+	atmark = is_sioctatmark(pfd);
+	if (!signal_recvd || len != 127 || !atmark) {
+		fprintf(stderr,
+			 "Test 3 Inline failed, sigurg %d len %d data %c\n",
+			 signal_recvd, len, buf[0]);
+		die(1);
+	}
+
+	len = read_data(pfd, buf, 1024);
+	atmark = is_sioctatmark(pfd);
+	if (len != 65 || buf[0] != '%' || atmark != 0) {
+		fprintf(stderr,
+			 "Test 3.1 Inline failed, len %d oob %c atmark %d\n",
+			 len, buf[0], atmark);
+		die(1);
+	}
+
+	signal_recvd = 0;
+	signal_producer(pipefd[1]);
+
+	/* Test 4 -- Inline:
+	 * verify that a single
+	 * byte oob message is delivered
+	 * and read returns one byte, the oob
+	 * byte and sigurg is received
+	 */
+	wait_for_data(pfd, POLLIN | POLLPRI);
+	len = read_data(pfd, buf, 1024);
+	if (!signal_recvd || len != 1 || buf[0] != '@') {
+		fprintf(stderr,
+			"Test 4 Inline failed, signal %d len %d data %c\n",
+		signal_recvd, len, buf[0]);
+		die(1);
+	}
+	die(0);
+}