From: Roy Marples <roy@marples.name>
Date: Fri, 7 Feb 2014 11:03:39 +0000 (+0000)
Subject: Don't hold onto an AF_INET socket for the duration of the program,
X-Git-Tag: v6.3.0~40
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=c7c1e4112a51092b025ed59790d30e0d59b4bf75;p=thirdparty%2Fdhcpcd.git

Don't hold onto an AF_INET socket for the duration of the program,
open and close it as required.
---

diff --git a/dhcpcd.c b/dhcpcd.c
index 8502a722..df1e7447 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -1313,11 +1313,6 @@ main(int argc, char **argv)
 			syslog(LOG_ERR, "control_start: %m");
 	}
 
-	if (open_sockets() == -1) {
-		syslog(LOG_ERR, "open_sockets: %m");
-		goto exit_failure;
-	}
-
 #if 0
 	if (options & DHCPCD_IPV6RS && disable_rtadv() == -1) {
 		syslog(LOG_ERR, "disable_rtadvd: %m");
@@ -1451,7 +1446,6 @@ exit1:
 	restore_kernel_ra();
 	ipv4_free(NULL);
 	ipv6_free(NULL);
-	if_free();
 	get_line_free();
 	dev_stop(options & DHCPCD_DAEMONISED);
 	if (linkfd != -1) {
diff --git a/if-bsd.c b/if-bsd.c
index 302abc0b..320e94ef 100644
--- a/if-bsd.c
+++ b/if-bsd.c
@@ -84,10 +84,6 @@
 #  define CLLADDR(s) ((const char *)((s)->sdl_data + (s)->sdl_nlen))
 #endif
 
-static int r_fd = -1;
-static char *link_buf;
-static ssize_t link_buflen;
-
 int
 if_init(__unused struct interface *iface)
 {
@@ -102,32 +98,6 @@ if_conf(__unused struct interface *iface)
 	return 0;
 }
 
-void
-if_free(void)
-{
-
-	if (r_fd != -1) {
-		close(r_fd);
-		r_fd = -1;
-	}
-	if (link_buflen) {
-		free(link_buf);
-		link_buflen = 0;
-	}
-}
-
-int
-open_sockets(void)
-{
-	if ((socket_afnet = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
-		return -1;
-	set_cloexec(socket_afnet);
-	if ((r_fd = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
-		return -1;
-	set_cloexec(r_fd);
-	return 0;
-}
-
 int
 open_link_socket(void)
 {
@@ -144,7 +114,7 @@ open_link_socket(void)
 int
 getifssid(const char *ifname, char *ssid)
 {
-	int retval = -1;
+	int s, retval = -1;
 #if defined(SIOCG80211NWID)
 	struct ifreq ifr;
 	struct ieee80211_nwid nwid;
@@ -153,12 +123,15 @@ getifssid(const char *ifname, char *ssid)
 	char nwid[IEEE80211_NWID_LEN + 1];
 #endif
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
+
 #if defined(SIOCG80211NWID) /* NetBSD */
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 	memset(&nwid, 0, sizeof(nwid));
 	ifr.ifr_data = (void *)&nwid;
-	if (ioctl(socket_afnet, SIOCG80211NWID, &ifr) == 0) {
+	if (ioctl(s, SIOCG80211NWID, &ifr) == 0) {
 		retval = nwid.i_len;
 		if (ssid) {
 			memcpy(ssid, nwid.i_nwid, nwid.i_len);
@@ -172,7 +145,7 @@ getifssid(const char *ifname, char *ssid)
 	ireq.i_val = -1;
 	memset(nwid, 0, sizeof(nwid));
 	ireq.i_data = &nwid;
-	if (ioctl(socket_afnet, SIOCG80211, &ireq) == 0) {
+	if (ioctl(s, SIOCG80211, &ireq) == 0) {
 		retval = ireq.i_len;
 		if (ssid) {
 			memcpy(ssid, nwid, ireq.i_len);
@@ -180,6 +153,8 @@ getifssid(const char *ifname, char *ssid)
 		}
 	}
 #endif
+
+	close(s);
 	return retval;
 }
 
@@ -193,11 +168,16 @@ getifssid(const char *ifname, char *ssid)
 int
 if_vimaster(const char *ifname)
 {
+	int s, r;
 	struct ifmediareq ifmr;
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
 	memset(&ifmr, 0, sizeof(ifmr));
 	strlcpy(ifmr.ifm_name, ifname, sizeof(ifmr.ifm_name));
-	if (ioctl(socket_afnet, SIOCGIFMEDIA, &ifmr) == -1)
+	r = ioctl(s, SIOCGIFMEDIA, &ifmr);
+	close(s);
+	if (r == -1)
 		return -1;
 	if (ifmr.ifm_status & IFM_AVALID &&
 	    IFM_TYPE(ifmr.ifm_active) == IFM_IEEE80211)
@@ -214,12 +194,16 @@ if_address(const struct interface *iface, const struct in_addr *address,
     const struct in_addr *netmask, const struct in_addr *broadcast,
     int action)
 {
+	int s, r;
 	struct ifaliasreq ifa;
 	union {
 		struct sockaddr *sa;
 		struct sockaddr_in *sin;
 	} _s;
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
+
 	memset(&ifa, 0, sizeof(ifa));
 	strlcpy(ifa.ifra_name, iface->name, sizeof(ifa.ifra_name));
 
@@ -237,9 +221,11 @@ if_address(const struct interface *iface, const struct in_addr *address,
 	}
 #undef ADDADDR
 
-	return ioctl(socket_afnet,
+	r = ioctl(s,
 	    action < 0 ? SIOCDIFADDR :
 	    action == 2 ? SIOCSIFADDR :  SIOCAIFADDR, &ifa);
+	close(s);
+	return r;
 }
 
 int
@@ -259,7 +245,10 @@ if_route(const struct rt *rt, int action)
 	} rtm;
 	char *bp = rtm.buffer;
 	size_t l;
-	int retval = 0;
+	int s, retval;
+
+	if ((s = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
+		return -1;
 
 #define ADDSU {								      \
 		l = RT_ROUNDUP(su.sa.sa_len);				      \
@@ -336,8 +325,9 @@ if_route(const struct rt *rt, int action)
 #undef ADDSU
 
 	rtm.hdr.rtm_msglen = l = bp - (char *)&rtm;
-	if (write(r_fd, &rtm, l) == -1)
-		retval = -1;
+
+	retval = write(s, &rtm, l) == -1 ? -1 : 0;
+	close(s);
 	return retval;
 }
 #endif
@@ -350,9 +340,9 @@ if_address6(const struct ipv6_addr *a, int action)
 	struct in6_aliasreq ifa;
 	struct in6_addr mask;
 
-	s = socket(AF_INET6, SOCK_DGRAM, 0);
-	if (s == -1)
+	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) == -1)
 		return -1;
+
 	memset(&ifa, 0, sizeof(ifa));
 	strlcpy(ifa.ifra_name, a->iface->name, sizeof(ifa.ifra_name));
 	/*
@@ -402,9 +392,12 @@ if_route6(const struct rt6 *rt, int action)
 	} rtm;
 	char *bp = rtm.buffer;
 	size_t l;
-	int retval = 0;
+	int s, retval;
 	const struct ipv6_addr_l *lla;
 
+	if ((s = socket(PF_ROUTE, SOCK_RAW, 0)) == -1)
+		return -1;
+
 /* KAME based systems want to store the scope inside the sin6_addr
  * for link local addreses */
 #ifdef __KAME__
@@ -507,8 +500,9 @@ if_route6(const struct rt6 *rt, int action)
 	}
 
 	rtm.hdr.rtm_msglen = l = bp - (char *)&rtm;
-	if (write(r_fd, &rtm, l) == -1)
-		retval = -1;
+
+	retval = write(s, &rtm, l) == -1 ? -1 : 0;
+	close(s);
 	return retval;
 }
 #endif
@@ -557,8 +551,8 @@ in6_addr_flags(const char *ifname, const struct in6_addr *addr)
 int
 manage_link(int fd)
 {
-	char *p, *e, *cp;
-	char ifname[IF_NAMESIZE];
+	/* route and ifwatchd like a msg buf size of 2048 */
+	char msg[2048], *p, *e, *cp, ifname[IF_NAMESIZE];
 	ssize_t bytes;
 	struct rt_msghdr *rtm;
 	struct if_announcemsghdr *ifan;
@@ -577,16 +571,7 @@ manage_link(int fd)
 #endif
 
 	for (;;) {
-		if (ioctl(fd, FIONREAD, &len) == -1)
-			return -1;
-		if (link_buflen < len) {
-			p = realloc(link_buf, len);
-			if (p == NULL)
-				return -1;
-			link_buf = p;
-			link_buflen = len;
-		}
-		bytes = read(fd, link_buf, link_buflen);
+		bytes = read(fd, msg, sizeof(msg));
 		if (bytes == -1) {
 			if (errno == EAGAIN)
 				return 0;
@@ -594,8 +579,8 @@ manage_link(int fd)
 				continue;
 			return -1;
 		}
-		e = link_buf + bytes;
-		for (p = link_buf; p < e; p += rtm->rtm_msglen) {
+		e = msg + bytes;
+		for (p = msg; p < e; p += rtm->rtm_msglen) {
 			rtm = (struct rt_msghdr *)(void *)p;
 			// Ignore messages generated by us
 			if (rtm->rtm_pid == getpid())
diff --git a/if-linux.c b/if-linux.c
index 6a932152..69b4ca7d 100644
--- a/if-linux.c
+++ b/if-linux.c
@@ -63,9 +63,6 @@
 #include "ipv6.h"
 #include "net.h"
 
-static int sock_fd;
-static struct sockaddr_nl sock_nl;
-
 int
 if_init(struct interface *iface)
 {
@@ -112,16 +109,6 @@ if_conf(struct interface *iface)
 	return 0;
 }
 
-void
-if_free(void)
-{
-
-	if (sock_fd != -1) {
-		close(sock_fd);
-		sock_fd = -1;
-	}
-}
-
 /* XXX work out Virtal Interface Masters */
 int
 if_vimaster(__unused const char *ifname)
@@ -145,17 +132,6 @@ _open_link_socket(struct sockaddr_nl *nl)
 	return fd;
 }
 
-int
-open_sockets(void)
-{
-	if ((socket_afnet = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
-		return -1;
-	set_cloexec(socket_afnet);
-	sock_fd = _open_link_socket(&sock_nl);
-	set_cloexec(sock_fd);
-	return sock_fd;
-}
-
 int
 open_link_socket(void)
 {
@@ -538,11 +514,14 @@ manage_link(int fd)
 static int
 send_netlink(struct nlmsghdr *hdr)
 {
-	int r;
+	int s, r;
+	struct sockaddr_nl sock_nl;
 	struct iovec iov;
 	struct msghdr msg;
 	static unsigned int seq;
 
+	if ((s = _open_link_socket(&sock_nl)) == -1)
+		return -1;
 	memset(&iov, 0, sizeof(iov));
 	iov.iov_base = hdr;
 	iov.iov_len = hdr->nlmsg_len;
@@ -555,10 +534,11 @@ send_netlink(struct nlmsghdr *hdr)
 	hdr->nlmsg_flags |= NLM_F_ACK;
 	hdr->nlmsg_seq = ++seq;
 
-	if (sendmsg(sock_fd, &msg, 0) != -1)
-		r = get_netlink(sock_fd, 0, &err_netlink);
+	if (sendmsg(s, &msg, 0) != -1)
+		r = get_netlink(s, 0, &err_netlink);
 	else
 		r = -1;
+	close(s);
 	return r;
 }
 
diff --git a/net.c b/net.c
index 13aa9a66..c440b924 100644
--- a/net.c
+++ b/net.c
@@ -1,6 +1,6 @@
 /*
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2013 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2014 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
@@ -75,8 +75,6 @@
 #include "ipv6nd.h"
 #include "net.h"
 
-int socket_afnet = -1;
-
 static char hwaddr_buffer[(HWADDR_LEN * 3) + 1 + 1024];
 
 char *
@@ -152,7 +150,7 @@ free_interface(struct interface *ifp)
 int
 carrier_status(struct interface *iface)
 {
-	int ret;
+	int s, r;
 	struct ifreq ifr;
 #ifdef SIOCGIFMEDIA
 	struct ifmediareq ifmr;
@@ -161,6 +159,8 @@ carrier_status(struct interface *iface)
 	char *p;
 #endif
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return LINK_UNKNOWN;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
 #ifdef __linux__
@@ -169,32 +169,37 @@ carrier_status(struct interface *iface)
 		*p = '\0';
 #endif
 
-	if (ioctl(socket_afnet, SIOCGIFFLAGS, &ifr) == -1)
+	if (ioctl(s, SIOCGIFFLAGS, &ifr) == -1) {
+		close(s);
 		return LINK_UNKNOWN;
+	}
 	iface->flags = ifr.ifr_flags;
 
-	ret = LINK_UNKNOWN;
+	r = LINK_UNKNOWN;
 #ifdef SIOCGIFMEDIA
 	memset(&ifmr, 0, sizeof(ifmr));
 	strlcpy(ifmr.ifm_name, iface->name, sizeof(ifmr.ifm_name));
-	if (ioctl(socket_afnet, SIOCGIFMEDIA, &ifmr) != -1 &&
+	if (ioctl(s, SIOCGIFMEDIA, &ifmr) != -1 &&
 	    ifmr.ifm_status & IFM_AVALID)
-		ret = (ifmr.ifm_status & IFM_ACTIVE) ? LINK_UP : LINK_DOWN;
+		r = (ifmr.ifm_status & IFM_ACTIVE) ? LINK_UP : LINK_DOWN;
 #endif
-	if (ret == LINK_UNKNOWN)
-		ret = (ifr.ifr_flags & IFF_RUNNING) ? LINK_UP : LINK_DOWN;
-	return ret;
+	if (r == LINK_UNKNOWN)
+		r = (ifr.ifr_flags & IFF_RUNNING) ? LINK_UP : LINK_DOWN;
+	close(s);
+	return r;
 }
 
-int
+static int
 up_interface(struct interface *iface)
 {
 	struct ifreq ifr;
-	int retval = -1;
+	int s, r;
 #ifdef __linux__
 	char *p;
 #endif
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, iface->name, sizeof(ifr.ifr_name));
 #ifdef __linux__
@@ -202,17 +207,19 @@ up_interface(struct interface *iface)
 	if ((p = strchr(ifr.ifr_name, ':')))
 		*p = '\0';
 #endif
-	if (ioctl(socket_afnet, SIOCGIFFLAGS, &ifr) == 0) {
+	r = -1;
+	if (ioctl(s, SIOCGIFFLAGS, &ifr) == 0) {
 		if ((ifr.ifr_flags & IFF_UP))
-			retval = 0;
+			r = 0;
 		else {
 			ifr.ifr_flags |= IFF_UP;
-			if (ioctl(socket_afnet, SIOCSIFFLAGS, &ifr) == 0)
-				retval = 0;
+			if (ioctl(s, SIOCSIFFLAGS, &ifr) == 0)
+				r = 0;
 		}
 		iface->flags = ifr.ifr_flags;
 	}
-	return retval;
+	close(s);
+	return r;
 }
 
 struct if_head *
@@ -508,13 +515,16 @@ discover_interfaces(int argc, char * const *argv)
 int
 do_mtu(const char *ifname, short int mtu)
 {
+	int s, r;
 	struct ifreq ifr;
-	int r;
 
+	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
+		return -1;
 	memset(&ifr, 0, sizeof(ifr));
 	strlcpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
 	ifr.ifr_mtu = mtu;
-	r = ioctl(socket_afnet, mtu ? SIOCSIFMTU : SIOCGIFMTU, &ifr);
+	r = ioctl(s, mtu ? SIOCSIFMTU : SIOCGIFMTU, &ifr);
+	close(s);
 	if (r == -1)
 		return -1;
 	return ifr.ifr_mtu;
diff --git a/net.h b/net.h
index 3962e88f..5ce1ff02 100644
--- a/net.h
+++ b/net.h
@@ -85,10 +85,6 @@
 # define IN_LINKLOCAL(addr) ((addr & IN_CLASSB_NET) == LINKLOCAL_ADDR)
 #endif
 
-extern int socket_afnet;
-
-int open_sockets(void);
-
 char *hwaddr_ntoa(const unsigned char *, size_t);
 size_t hwaddr_aton(unsigned char *, const char *);
 
@@ -100,10 +96,8 @@ int do_mtu(const char *, short int);
 #define get_mtu(iface) do_mtu(iface, 0)
 #define set_mtu(iface, mtu) do_mtu(iface, mtu)
 
-int up_interface(struct interface *);
 int if_conf(struct interface *);
 int if_init(struct interface *);
-void if_free(void);
 
 int open_link_socket(void);
 int manage_link(int);