From 812d24c91aecff78369f32f6593045f24d578d38 Mon Sep 17 00:00:00 2001

From: Stefano Brivio <sbrivio@redhat.com>

Date: Wed, 8 Mar 2023 12:14:29 +0100

Subject: [PATCH 13/20] tcp, udp, util: Pass socket creation errors all the way

 up

...starting from sock_l4(), pass negative error (errno) codes instead

of -1. They will only be used in two commits from now, no functional

changes intended here.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

(cherry picked from commit 73992c42cea0df56f6ba0a3bef0f4a939f26ebad)

---

 tcp.c  | 22 ++++++++++++----------

 udp.c  | 18 +++++++++---------

 util.c | 31 ++++++++++++++++++-------------

 3 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/tcp.c b/tcp.c

index fe6e458..482c2f9 100644

--- a/tcp.c

+++ b/tcp.c

@@ -2891,7 +2891,7 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events,

  * @addr:	Pointer to address for binding, NULL if not configured

  * @ifname:	Name of interface to bind to, NULL if not configured

  *

- * Return: fd for the new listening socket, or -1 on failure

+ * Return: fd for the new listening socket, negative error code on failure

  */

 static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,

 			    const struct in_addr *addr, const char *ifname)

@@ -2904,13 +2904,13 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,

 	if (c->tcp.fwd_in.mode == FWD_AUTO) {

 		if (af == AF_INET  || af == AF_UNSPEC)

-			tcp_sock_init_ext[port][V4] = s;

+			tcp_sock_init_ext[port][V4] = s < 0 ? -1 : s;

 		if (af == AF_INET6 || af == AF_UNSPEC)

-			tcp_sock_init_ext[port][V6] = s;

+			tcp_sock_init_ext[port][V6] = s < 0 ? -1 : s;

 	}

 	if (s < 0)

-		return -1;

+		return s;

 	tcp_sock_set_bufsize(c, s);

 	return s;

@@ -2924,12 +2924,12 @@ static int tcp_sock_init_af(const struct ctx *c, int af, in_port_t port,

  * @ifname:	Name of interface to bind to, NULL if not configured

  * @port:	Port, host order

  *

- * Return: 0 on (partial) success, -1 on (complete) failure

+ * Return: 0 on (partial) success, negative error code on (complete) failure

  */

 int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,

 		  const char *ifname, in_port_t port)

 {

-	int ret = 0;

+	int ret = 0, af_ret;

 	if (af == AF_UNSPEC && c->ifi4 && c->ifi6)

 		/* Attempt to get a dual stack socket */

@@ -2938,13 +2938,15 @@ int tcp_sock_init(const struct ctx *c, sa_family_t af, const void *addr,

 	/* Otherwise create a socket per IP version */

 	if ((af == AF_INET  || af == AF_UNSPEC) && c->ifi4) {

-		if (tcp_sock_init_af(c, AF_INET, port, addr, ifname) < 0)

-			ret = -1;

+		af_ret = tcp_sock_init_af(c, AF_INET, port, addr, ifname);

+		if (af_ret < 0)

+			ret = af_ret;

 	}

 	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) {

-		if (tcp_sock_init_af(c, AF_INET6, port, addr, ifname) < 0)

-			ret = -1;

+		af_ret = tcp_sock_init_af(c, AF_INET6, port, addr, ifname);

+		if (af_ret < 0)

+			ret = af_ret;

 	}

 	return ret;

diff --git a/udp.c b/udp.c

index 20a9ea0..9a43835 100644

--- a/udp.c

+++ b/udp.c

@@ -956,7 +956,7 @@ int udp_tap_handler(struct ctx *c, int af, const void *addr,

  * @ifname:	Name of interface to bind to, NULL if not configured

  * @port:	Port, host order

  *

- * Return: 0 on (partial) success, -1 on (complete) failure

+ * Return: 0 on (partial) success, negative error code on (complete) failure

  */

 int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,

 		  const void *addr, const char *ifname, in_port_t port)

@@ -981,19 +981,19 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,

 			s = sock_l4(c, AF_INET, IPPROTO_UDP, addr, ifname,

 				    port, uref.u32);

-			udp_tap_map[V4][uref.udp.port].sock = s;

-			udp_splice_init[V4][port].sock = s;

+			udp_tap_map[V4][uref.udp.port].sock = s < 0 ? -1 : s;

+			udp_splice_init[V4][port].sock = s < 0 ? -1 : s;

 		} else {

 			struct in_addr loopback = { htonl(INADDR_LOOPBACK) };

 			uref.udp.ns = true;

 			s = sock_l4(c, AF_INET, IPPROTO_UDP, &loopback,

 				    ifname, port, uref.u32);

-			udp_splice_ns[V4][port].sock = s;

+			udp_splice_ns[V4][port].sock = s < 0 ? -1 : s;

 		}

 		if (s < 0)

-			ret = -1;

+			ret = s;

 	}

 	if ((af == AF_INET6 || af == AF_UNSPEC) && c->ifi6) {

@@ -1005,18 +1005,18 @@ int udp_sock_init(const struct ctx *c, int ns, sa_family_t af,

 			s = sock_l4(c, AF_INET6, IPPROTO_UDP, addr, ifname,

 				    port, uref.u32);

-			udp_tap_map[V6][uref.udp.port].sock = s;

-			udp_splice_init[V6][port].sock = s;

+			udp_tap_map[V6][uref.udp.port].sock = s < 0 ? -1 : s;

+			udp_splice_init[V6][port].sock = s < 0 ? -1 : s;

 		} else {

 			uref.udp.ns = true;

 			s = sock_l4(c, AF_INET6, IPPROTO_UDP, &in6addr_loopback,

 				    ifname, port, uref.u32);

-			udp_splice_ns[V6][port].sock = s;

+			udp_splice_ns[V6][port].sock = s < 0 ? -1 : s;

 		}

 		if (s < 0)

-			ret = -1;

+			ret = s;

 	}

 	return ret;

diff --git a/util.c b/util.c

index c5ee1c0..13f8fab 100644

--- a/util.c

+++ b/util.c

@@ -95,7 +95,7 @@ found:

  * @port:	Port, host order

  * @data:	epoll reference portion for protocol handlers

  *

- * Return: newly created socket, -1 on error

+ * Return: newly created socket, negative error code on failure

  */

 int sock_l4(const struct ctx *c, int af, uint8_t proto,

 	    const void *bind_addr, const char *ifname, uint16_t port,

@@ -114,16 +114,16 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,

 	};

 	const struct sockaddr *sa;

 	bool dual_stack = false;

+	int fd, sl, y = 1, ret;

 	struct epoll_event ev;

-	int fd, sl, y = 1;

 	if (proto != IPPROTO_TCP && proto != IPPROTO_UDP &&

 	    proto != IPPROTO_ICMP && proto != IPPROTO_ICMPV6)

-		return -1;	/* Not implemented. */

+		return -EPFNOSUPPORT;	/* Not implemented. */

 	if (af == AF_UNSPEC) {

 		if (!DUAL_STACK_SOCKETS || bind_addr)

-			return -1;

+			return -EINVAL;

 		dual_stack = true;

 		af = AF_INET6;

 	}

@@ -133,14 +133,15 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,

 	else

 		fd = socket(af, SOCK_DGRAM | SOCK_NONBLOCK, proto);

+	ret = -errno;

 	if (fd < 0) {

-		warn("L4 socket: %s", strerror(errno));

-		return -1;

+		warn("L4 socket: %s", strerror(-ret));

+		return ret;

 	}

 	if (fd > SOCKET_MAX) {

 		close(fd);

-		return -1;

+		return -EBADF;

 	}

 	ref.r.s = fd;

@@ -185,10 +186,11 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,

 		 */

 		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE,

 			       ifname, strlen(ifname))) {

+			ret = -errno;

 			warn("Can't bind socket for %s port %u to %s, closing",

 			     ip_proto_str[proto], port, ifname);

 			close(fd);

-			return -1;

+			return ret;

 		}

 	}

@@ -199,22 +201,25 @@ int sock_l4(const struct ctx *c, int af, uint8_t proto,

 		 * broken SELinux policy, see icmp_tap_handler().

 		 */

 		if (proto != IPPROTO_ICMP && proto != IPPROTO_ICMPV6) {

+			ret = -errno;

 			close(fd);

-			return -1;

+			return ret;

 		}

 	}

 	if (proto == IPPROTO_TCP && listen(fd, 128) < 0) {

-		warn("TCP socket listen: %s", strerror(errno));

+		ret = -errno;

+		warn("TCP socket listen: %s", strerror(-ret));

 		close(fd);

-		return -1;

+		return ret;

 	}

 	ev.events = EPOLLIN;

 	ev.data.u64 = ref.u64;

 	if (epoll_ctl(c->epollfd, EPOLL_CTL_ADD, fd, &ev) == -1) {

-		warn("L4 epoll_ctl: %s", strerror(errno));

-		return -1;

+		ret = -errno;

+		warn("L4 epoll_ctl: %s", strerror(-ret));

+		return ret;

 	}

 	return fd;

-- 

2.39.2