From 314001f0bf927015e459c9d387d62a231fe93af3 Mon Sep 17 00:00:00 2001 From: Rao Shoaib Date: Sun, 1 Aug 2021 00:57:07 -0700 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- include/net/af_unix.h | 3 + net/unix/Kconfig | 5 + net/unix/af_unix.c | 153 +++++- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/net/af_unix/Makefile | 5 + .../selftests/net/af_unix/test_unix_oob.c | 437 ++++++++++++++++++ 6 files changed, 602 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/net/af_unix/Makefile create mode 100644 tools/testing/selftests/net/af_unix/test_unix_oob.c diff --git a/include/net/af_unix.h b/include/net/af_unix.h index 435a2c3d5a6f..4757d7f53f13 100644 --- a/include/net/af_unix.h +++ b/include/net/af_unix.h @@ -70,6 +70,9 @@ struct unix_sock { struct socket_wq peer_wq; wait_queue_entry_t peer_wake; struct scm_stat scm_stat; +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + struct sk_buff *oob_skb; +#endif }; static inline struct unix_sock *unix_sk(const struct sock *sk) diff --git a/net/unix/Kconfig b/net/unix/Kconfig index b6c4282899ec..b7f811216820 100644 --- a/net/unix/Kconfig +++ b/net/unix/Kconfig @@ -25,6 +25,11 @@ config UNIX_SCM depends on UNIX default y +config AF_UNIX_OOB + bool + depends on UNIX + default y + config UNIX_DIAG tristate "UNIX: socket monitoring interface" depends on UNIX diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 256c4e31132e..ec02e70a549b 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -503,6 +503,12 @@ static void unix_sock_destructor(struct sock *sk) skb_queue_purge(&sk->sk_receive_queue); +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + if (u->oob_skb) { + kfree_skb(u->oob_skb); + u->oob_skb = NULL; + } +#endif WARN_ON(refcount_read(&sk->sk_wmem_alloc)); WARN_ON(!sk_unhashed(sk)); WARN_ON(sk->sk_socket); @@ -1889,6 +1895,46 @@ out: */ #define UNIX_SKB_FRAGS_SZ (PAGE_SIZE << get_order(32768)) +#if (IS_ENABLED(CONFIG_AF_UNIX_OOB)) +static int queue_oob(struct socket *sock, struct msghdr *msg, struct sock *other) +{ + struct unix_sock *ousk = unix_sk(other); + struct sk_buff *skb; + int err = 0; + + skb = sock_alloc_send_skb(sock->sk, 1, msg->msg_flags & MSG_DONTWAIT, &err); + + if (!skb) + return err; + + skb_put(skb, 1); + skb->len = 1; + err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, 1); + + if (err) { + kfree_skb(skb); + return err; + } + + unix_state_lock(other); + maybe_add_creds(skb, sock, other); + skb_get(skb); + + if (ousk->oob_skb) + kfree_skb(ousk->oob_skb); + + ousk->oob_skb = skb; + + scm_stat_add(other, skb); + skb_queue_tail(&other->sk_receive_queue, skb); + sk_send_sigurg(other); + unix_state_unlock(other); + other->sk_data_ready(other); + + return err; +} +#endif + static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { @@ -1907,8 +1953,14 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, return err; err = -EOPNOTSUPP; - if (msg->msg_flags&MSG_OOB) - goto out_err; + if (msg->msg_flags & MSG_OOB) { +#if (IS_ENABLED(CONFIG_AF_UNIX_OOB)) + if (len) + len--; + else +#endif + goto out_err; + } if (msg->msg_namelen) { err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP; @@ -1973,6 +2025,15 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, sent += size; } +#if (IS_ENABLED(CONFIG_AF_UNIX_OOB)) + if (msg->msg_flags & MSG_OOB) { + err = queue_oob(sock, msg, other); + if (err) + goto out_err; + sent++; + } +#endif + scm_destroy(&scm); return sent; @@ -2358,6 +2419,59 @@ struct unix_stream_read_state { unsigned int splice_flags; }; +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) +static int unix_stream_recv_urg(struct unix_stream_read_state *state) +{ + struct socket *sock = state->socket; + struct sock *sk = sock->sk; + struct unix_sock *u = unix_sk(sk); + int chunk = 1; + + if (sock_flag(sk, SOCK_URGINLINE) || !u->oob_skb) + return -EINVAL; + + chunk = state->recv_actor(u->oob_skb, 0, chunk, state); + if (chunk < 0) + return -EFAULT; + + if (!(state->flags & MSG_PEEK)) { + UNIXCB(u->oob_skb).consumed += 1; + kfree_skb(u->oob_skb); + u->oob_skb = NULL; + } + state->msg->msg_flags |= MSG_OOB; + return 1; +} + +static struct sk_buff *manage_oob(struct sk_buff *skb, struct sock *sk, + int flags, int copied) +{ + struct unix_sock *u = unix_sk(sk); + + if (!unix_skb_len(skb) && !(flags & MSG_PEEK)) { + skb_unlink(skb, &sk->sk_receive_queue); + consume_skb(skb); + skb = NULL; + } else { + if (skb == u->oob_skb) { + if (copied) { + skb = NULL; + } else if (sock_flag(sk, SOCK_URGINLINE)) { + if (!(flags & MSG_PEEK)) { + u->oob_skb = NULL; + consume_skb(skb); + } + } else if (!(flags & MSG_PEEK)) { + skb_unlink(skb, &sk->sk_receive_queue); + consume_skb(skb); + skb = skb_peek(&sk->sk_receive_queue); + } + } + } + return skb; +} +#endif + static int unix_stream_read_generic(struct unix_stream_read_state *state, bool freezable) { @@ -2383,6 +2497,15 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, if (unlikely(flags & MSG_OOB)) { err = -EOPNOTSUPP; +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + mutex_lock(&u->iolock); + unix_state_lock(sk); + + err = unix_stream_recv_urg(state); + + unix_state_unlock(sk); + mutex_unlock(&u->iolock); +#endif goto out; } @@ -2411,6 +2534,18 @@ redo: } last = skb = skb_peek(&sk->sk_receive_queue); last_len = last ? last->len : 0; + +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + if (skb) { + skb = manage_oob(skb, sk, flags, copied); + if (!skb) { + unix_state_unlock(sk); + if (copied) + break; + goto redo; + } + } +#endif again: if (skb == NULL) { if (copied >= target) @@ -2746,6 +2881,20 @@ static int unix_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg) case SIOCUNIXFILE: err = unix_open_file(sk); break; +#if IS_ENABLED(CONFIG_AF_UNIX_OOB) + case SIOCATMARK: + { + struct sk_buff *skb; + struct unix_sock *u = unix_sk(sk); + int answ = 0; + + skb = skb_peek(&sk->sk_receive_queue); + if (skb && skb == u->oob_skb) + answ = 1; + err = put_user(answ, (int __user *)arg); + } + break; +#endif default: err = -ENOIOCTLCMD; break; 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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); +}