45e3967c2

Denys Vlasenko

2019-06-03

SUCCESS Duration: 152s

Subject

libbb: move netlink socket binding to the utility function

No binary (build failed)

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

(log yok)

include/libbb.h+1 -0

@@ -688,6 +688,7 @@ int xsocket_stream(len_and_sockaddr **lsap) FAST_FUNC;
	/* NB: these set SO_REUSEADDR before bind */
	int create_and_bind_stream_or_die(const char *bindaddr, int port) FAST_FUNC;
	int create_and_bind_dgram_or_die(const char *bindaddr, int port) FAST_FUNC;
+	int create_and_bind_to_netlink(int proto, int grp, unsigned rcvbuf) FAST_FUNC;
	/* Create client TCP socket connected to peer:port. Peer cannot be NULL.
	* Peer can be numeric IP ("N.N.N.N"), numeric IPv6 address or hostname,
	* and can have ":PORT" suffix (for IPv6 use "[X:X:...:X]:PORT").

libbb/xconnect.c+35 -0

@@ -11,6 +11,9 @@
	#include <netinet/in.h>
	#include <net/if.h>
	#include <sys/un.h>
+	#if ENABLE_IFPLUGD \|\| ENABLE_FEATURE_MDEV_DAEMON \|\| ENABLE_UEVENT
+	# include <linux/netlink.h>
+	#endif
	#include "libbb.h"

	int FAST_FUNC setsockopt_int(int fd, int level, int optname, int optval)
@@ -412,6 +415,38 @@ int FAST_FUNC create_and_bind_dgram_or_die(const char *bindaddr, int port)
	}


+	#if ENABLE_IFPLUGD \|\| ENABLE_FEATURE_MDEV_DAEMON \|\| ENABLE_UEVENT
+	int FAST_FUNC create_and_bind_to_netlink(int proto, int grp, unsigned rcvbuf)
+	{
+	struct sockaddr_nl sa;
+	int fd;
+
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+	sa.nl_pid = getpid();
+	sa.nl_groups = grp;
+	fd = xsocket(AF_NETLINK, SOCK_DGRAM, proto);
+	xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
+	close_on_exec_on(fd);
+
+	if (rcvbuf != 0) {
+	// SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
+	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, rcvbuf);
+	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, rcvbuf);
+	# if 0
+	{
+	int z;
+	socklen_t zl = sizeof(z);
+	getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &z, &zl);
+	bb_error_msg("SO_RCVBUF:%d", z);
+	}
+	# endif
+	}
+
+	return fd;
+	}
+	#endif
+
	int FAST_FUNC create_and_connect_stream_or_die(const char *peer, int port)
	{
	int fd;

networking/ifplugd.c+1 -9

@@ -604,15 +604,7 @@ int ifplugd_main(int argc UNUSED_PARAM, char **argv)

	xmove_fd(xsocket(AF_INET, SOCK_DGRAM, 0), ioctl_fd);
	if (opts & FLAG_MONITOR) {
-	struct sockaddr_nl addr;
-	int fd = xsocket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
-
-	memset(&addr, 0, sizeof(addr));
-	addr.nl_family = AF_NETLINK;
-	addr.nl_groups = RTMGRP_LINK;
-	addr.nl_pid = getpid();
-
-	xbind(fd, (struct sockaddr*)&addr, sizeof(addr));
+	int fd = create_and_bind_to_netlink(NETLINK_ROUTE, RTMGRP_LINK, 0);
	xmove_fd(fd, netlink_fd);
	}

util-linux/mdev.c+8 -20

@@ -1225,28 +1225,16 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
	/*
	* Daemon mode listening on uevent netlink socket.
	*/
-	struct sockaddr_nl sa;
	int fd;

-	//TODO: reuse same code in uevent
-	// Subscribe for UEVENT kernel messages
-	sa.nl_family = AF_NETLINK;
-	sa.nl_pad = 0;
-	sa.nl_pid = getpid();
-	sa.nl_groups = 1 << 0;
-	fd = xsocket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
-	xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
-	close_on_exec_on(fd);
-
-	// Without a sufficiently big RCVBUF, a ton of simultaneous events
-	// can trigger ENOBUFS on read, which is unrecoverable.
-	// Reproducer:
-	// mdev -d
-	// find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
-	//
-	// SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
-	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, RCVBUF);
-	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, RCVBUF);
+	/* Subscribe for UEVENT kernel messages */
+	/* Without a sufficiently big RCVBUF, a ton of simultaneous events
+	* can trigger ENOBUFS on read, which is unrecoverable.
+	* Reproducer:
+	* mdev -d
+	* find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
+	*/
+	fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0, RCVBUF);

	/*
	* Make inital scan after the uevent socket is alive and

util-linux/uevent.c+10 -27

@@ -46,37 +46,19 @@ enum { RCVBUF = 2 * 1024 * 1024 };
	int uevent_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
	int uevent_main(int argc UNUSED_PARAM, char **argv)
	{
-	struct sockaddr_nl sa;
	int fd;

	INIT_G();

	argv++;

-	// Subscribe for UEVENT kernel messages
-	sa.nl_family = AF_NETLINK;
-	sa.nl_pad = 0;
-	sa.nl_pid = getpid();
-	sa.nl_groups = 1 << 0;
-	fd = xsocket(AF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
-	xbind(fd, (struct sockaddr *) &sa, sizeof(sa));
-	close_on_exec_on(fd);
-
+	// Subscribe for UEVENT kernel messages.
	// Without a sufficiently big RCVBUF, a ton of simultaneous events
	// can trigger ENOBUFS on read, which is unrecoverable.
	// Reproducer:
	// uevent mdev &
	// find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
-	//
-	// SO_RCVBUFFORCE (root only) can go above net.core.rmem_max sysctl
-	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUF, RCVBUF);
-	setsockopt_SOL_SOCKET_int(fd, SO_RCVBUFFORCE, RCVBUF);
-	if (0) {
-	int z;
-	socklen_t zl = sizeof(z);
-	getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &z, &zl);
-	bb_error_msg("SO_RCVBUF:%d", z);
-	}
+	fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, /groups:/ 1 << 0, RCVBUF);

	for (;;) {
	char *netbuf;
@@ -118,14 +100,15 @@ int uevent_main(int argc UNUSED_PARAM, char **argv)
	}
	env[idx] = NULL;

-	idx = 0;
-	while (env[idx])
-	putenv(env[idx++]);
-	if (argv[0])
+	if (argv[0]) {
+	idx = 0;
+	while (env[idx])
+	putenv(env[idx++]);
	spawn_and_wait(argv);
-	idx = 0;
-	while (env[idx])
-	bb_unsetenv(env[idx++]);
+	idx = 0;
+	while (env[idx])
+	bb_unsetenv(env[idx++]);
+	}
	munmap(netbuf, BUFFER_SIZE);
	}