Attachment 573612 Details for Bug 803540 – Use getifaddrs() for interface discovery code on Linux

[patch] Use getifaddrs() for interface discovery code on Linux

dhcp-4.1.1-P1-getifaddrs.patch (text/plain), 10.28 KB, created by Jiri Popelka on 2012-03-29 10:09:10 UTC

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Creator: Jiri Popelka

Created: 2012-03-29 10:09:10 UTC

Size: 10.28 KB

patch

obsolete

>diff -up dhcp-4.1.1-P1/common/discover.c.getifaddrs dhcp-4.1.1-P1/common/discover.c
>--- dhcp-4.1.1-P1/common/discover.c.getifaddrs	2012-03-21 16:08:18.535717842 +0100
>+++ dhcp-4.1.1-P1/common/discover.c	2012-03-21 16:09:04.079723354 +0100
>@@ -367,394 +367,13 @@ end_iface_scan(struct iface_conf_list *i
> 	ifaces->sock = -1;
> }
> 
>-#elif __linux /* !HAVE_SIOCGLIFCONF */
>-/* 
>- * Linux support
>- * -------------
>- *
>- * In Linux, we use the /proc pseudo-filesystem to get information
>- * about interfaces, along with selected ioctl() calls.
>- *
>- * Linux low level access is documented in the netdevice man page.
>- */
>-
>-/* 
>- * Structure holding state about the scan.
>- */
>-struct iface_conf_list {
>-	int sock;	/* file descriptor used to get information */
>-	FILE *fp;	/* input from /proc/net/dev */
>-#ifdef DHCPv6
>-	FILE *fp6;	/* input from /proc/net/if_inet6 */
>-#endif
>-};
>-
>-/* 
>- * Structure used to return information about a specific interface.
>- */
>-struct iface_info {
>-	char name[IFNAMSIZ];		/* name of the interface, e.g. "eth0" */
>-	struct sockaddr_storage addr;	/* address information */
>-	isc_uint64_t flags;		/* interface flags, e.g. IFF_LOOPBACK */
>-};
>-
>-/* 
>- * Start a scan of interfaces.
>- *
>- * The iface_conf_list structure maintains state for this process.
>- */
>-int 
>-begin_iface_scan(struct iface_conf_list *ifaces) {
>-	char buf[256];
>-	int len;
>-	int i;
>-
>-	ifaces->fp = fopen("/proc/net/dev", "re");
>-	if (ifaces->fp == NULL) {
>-		log_error("Error opening '/proc/net/dev' to list interfaces");
>-		return 0;
>-	}
>-
>-	/*
>-	 * The first 2 lines are header information, so read and ignore them.
>-	 */
>-	for (i=0; i<2; i++) {
>-		if (fgets(buf, sizeof(buf), ifaces->fp) == NULL) {
>-			log_error("Error reading headers from '/proc/net/dev'");
>-			fclose(ifaces->fp);
>-			ifaces->fp = NULL;
>-			return 0;
>-		}
>-		len = strlen(buf);
>-		if ((len <= 0) || (buf[len-1] != '\n')) { 
>-			log_error("Bad header line in '/proc/net/dev'");
>-			fclose(ifaces->fp);
>-			ifaces->fp = NULL;
>-			return 0;
>-		}
>-	}
>-
>-	ifaces->sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
>-	if (ifaces->sock < 0) {
>-		log_error("Error creating socket to list interfaces; %m");
>-		fclose(ifaces->fp);
>-		ifaces->fp = NULL;
>-		return 0;
>-	}
>-
>-#ifdef DHCPv6
>-	if ((local_family == AF_INET6) && !access("/proc/net/if_inet6", R_OK)) {
>-		ifaces->fp6 = fopen("/proc/net/if_inet6", "re");
>-		if (ifaces->fp6 == NULL) {
>-			log_error("Error opening '/proc/net/if_inet6' to "
>-				  "list IPv6 interfaces; %m");
>-			close(ifaces->sock);
>-			ifaces->sock = -1;
>-			fclose(ifaces->fp);
>-			ifaces->fp = NULL;
>-			return 0;
>-		}
>-	} else {
>-		ifaces->fp6 = NULL;
>-	}
>-#endif
>-
>-	return 1;
>-}
>-
>-/*
>- * Read our IPv4 interfaces from /proc/net/dev.
>- *
>- * The file looks something like this:
>- *
>- * Inter-|   Receive ...
>- *  face |bytes    packets errs drop fifo frame ...
>- *     lo: 1580562    4207    0    0    0     0 ...
>- *   eth0:       0       0    0    0    0     0 ...
>- *   eth1:1801552440   37895    0   14    0     ...
>- *
>- * We only care about the interface name, which is at the start of 
>- * each line.
>- *
>- * We use an ioctl() to get the address and flags for each interface.
>- */
>-static int
>-next_iface4(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
>-	char buf[256];
>-	int len;
>-	char *p;
>-	char *name;
>-	struct ifreq tmp;
>-
>-	/*
>-	 * Loop exits when we find an interface that has an address, or 
>-	 * when we run out of interfaces.
>-	 */
>-	for (;;) {
>-		do {
>-			/*
>-	 		 *  Read the next line in the file.
>-	 		 */
>-			if (fgets(buf, sizeof(buf), ifaces->fp) == NULL) {
>-				if (ferror(ifaces->fp)) {
>-					*err = 1;
>-					log_error("Error reading interface "
>-					  	"information");
>-				} else {
>-					*err = 0;
>-				}
>-				return 0;
>-			}
>-
>-			/*
>-	 		 * Make sure the line is a nice, 
>-			 * newline-terminated line.
>-	 		 */
>-			len = strlen(buf);
>-			if ((len <= 0) || (buf[len-1] != '\n')) { 
>-				log_error("Bad line reading interface "
>-					  "information");
>-				*err = 1;
>-				return 0;
>-			}
>-
>-			/*
>-	 		 * Figure out our name.
>-	 		 */
>-			p = strrchr(buf, ':');
>-			if (p == NULL) {
>-				log_error("Bad line reading interface "
>-					  "information (no colon)");
>-				*err = 1;
>-				return 0;
>-			}
>-			*p = '\0';
>-			name = buf;
>-			while (isspace(*name)) {
>-				name++;
>-			}
>-
>-			/* 
>-		 	 * Copy our name into our interface structure.
>-		 	 */
>-			len = p - name;
>-			if (len >= sizeof(info->name)) {
>-				*err = 1;
>-				log_error("Interface name '%s' too long", name);
>-				return 0;
>-			}
>-			strcpy(info->name, name);
>-
>-#ifdef ALIAS_NAMED_PERMUTED
>-			/* interface aliases look like "eth0:1" or "wlan1:3" */
>-			s = strchr(info->name, ':');
>-			if (s != NULL) {
>-				*s = '\0';
>-			}
>-#endif
>-
>-#ifdef SKIP_DUMMY_INTERFACES
>-		} while (strncmp(info->name, "dummy", 5) == 0);
>-#else
>-		} while (0);
>-#endif
>-
>-		memset(&tmp, 0, sizeof(tmp));
>-		strcpy(tmp.ifr_name, name);
>-		if (ioctl(ifaces->sock, SIOCGIFADDR, &tmp) < 0) {
>-			if (errno == EADDRNOTAVAIL) {
>-				continue;
>-			}
>-			log_error("Error getting interface address "
>-				  "for '%s'; %m", name);
>-			*err = 1;
>-			return 0;
>-		}
>-		memcpy(&info->addr, &tmp.ifr_addr, sizeof(tmp.ifr_addr));
>-
>-		memset(&tmp, 0, sizeof(tmp));
>-		strcpy(tmp.ifr_name, name);
>-		if (ioctl(ifaces->sock, SIOCGIFFLAGS, &tmp) < 0) {
>-			log_error("Error getting interface flags for '%s'; %m", 
>-			  	name);
>-			*err = 1;
>-			return 0;
>-		}
>-		info->flags = tmp.ifr_flags;
>-
>-		*err = 0;
>-		return 1;
>-	}
>-}
>-
>-#ifdef DHCPv6
>-/*
>- * Read our IPv6 interfaces from /proc/net/if_inet6.
>- *
>- * The file looks something like this:
>- *
>- * fe80000000000000025056fffec00008 05 40 20 80   vmnet8
>- * 00000000000000000000000000000001 01 80 10 80       lo
>- * fe80000000000000025056fffec00001 06 40 20 80   vmnet1
>- * 200108881936000202166ffffe497d9b 03 40 00 00     eth1
>- * fe8000000000000002166ffffe497d9b 03 40 20 80     eth1
>- *
>- * We get IPv6 address from the start, the interface name from the end, 
>- * and ioctl() to get flags.
>- */
>-static int
>-next_iface6(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
>-	char buf[256];
>-	int len;
>-	char *p;
>-	char *name;
>-	int i;
>-	struct sockaddr_in6 addr;
>-	struct ifreq tmp;
>-
>-	do {
>-		/*
>-		 *  Read the next line in the file.
>-		 */
>-		if (fgets(buf, sizeof(buf), ifaces->fp6) == NULL) {
>-			if (ferror(ifaces->fp6)) {
>-				*err = 1;
>-				log_error("Error reading IPv6 "
>-					  "interface information");
>-			} else {
>-				*err = 0;
>-			}
>-			return 0;
>-		}
>-
>-		/*
>-		 * Make sure the line is a nice, newline-terminated line.
>-		 */
>-		len = strlen(buf);
>-		if ((len <= 0) || (buf[len-1] != '\n')) { 
>-			log_error("Bad line reading IPv6 "
>-				  "interface information");
>-			*err = 1;
>-			return 0;
>-		}
>-
>-		/*
>- 		 * Figure out our name.
>- 		 */
>-		buf[--len] = '\0';
>-		p = strrchr(buf, ' ');
>-		if (p == NULL) {
>-			log_error("Bad line reading IPv6 interface "
>-			          "information (no space)");
>-			*err = 1;
>-			return 0;
>-		}
>-		name = p+1;
>-
>-		/* 
>- 		 * Copy our name into our interface structure.
>- 		 */
>-		len = strlen(name);
>-		if (len >= sizeof(info->name)) {
>-			*err = 1;
>-			log_error("IPv6 interface name '%s' too long", name);
>-			return 0;
>-		}
>-		strcpy(info->name, name);
>-
>-#ifdef SKIP_DUMMY_INTERFACES
>-	} while (strncmp(info->name, "dummy", 5) == 0);
>-#else
>-	} while (0);
>-#endif
>-
>-	/*
>-	 * Double-check we start with the IPv6 address.
>-	 */
>-	for (i=0; i<32; i++) {
>-		if (!isxdigit(buf[i]) || isupper(buf[i])) {
>-			*err = 1;
>-			log_error("Bad line reading IPv6 interface address "
>-				  "for '%s'", name);
>-			return 0;
>-		}
>-	}
>-
>-	/* 
>-	 * Load our socket structure.
>-	 */
>-	memset(&addr, 0, sizeof(addr));
>-	addr.sin6_family = AF_INET6;
>-	for (i=0; i<16; i++) {
>-		unsigned char byte;
>-                static const char hex[] = "0123456789abcdef";
>-                byte = ((index(hex, buf[i * 2]) - hex) << 4) |
>-			(index(hex, buf[i * 2 + 1]) - hex);
>-		addr.sin6_addr.s6_addr[i] = byte;
>-	}
>-	memcpy(&info->addr, &addr, sizeof(addr));
>-
>-	/*
>-	 * Get our flags.
>-	 */
>-	memset(&tmp, 0, sizeof(tmp));
>-	strcpy(tmp.ifr_name, name);
>-	if (ioctl(ifaces->sock, SIOCGIFFLAGS, &tmp) < 0) {
>-		log_error("Error getting interface flags for '%s'; %m", name);
>-		*err = 1;
>-		return 0;
>-	}
>-	info->flags = tmp.ifr_flags;
>-
>-	*err = 0;
>-	return 1;
>-}
>-#endif /* DHCPv6 */
>-
>-/*
>- * Retrieve the next interface.
>- *
>- * Returns information in the info structure. 
>- * Sets err to 1 if there is an error, otherwise 0.
>- */
>-int
>-next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
>-	if (next_iface4(info, err, ifaces)) {
>-		return 1;
>-	}
>-#ifdef DHCPv6
>-	if (!(*err) && ifaces->fp6) {
>-		if (local_family == AF_INET6)
>-			return next_iface6(info, err, ifaces);
>-	}
>-#endif
>-	return 0;
>-}
>-
>-/*
>- * End scan of interfaces.
>- */
>-void
>-end_iface_scan(struct iface_conf_list *ifaces) {
>-	fclose(ifaces->fp);
>-	ifaces->fp = NULL;
>-	close(ifaces->sock);
>-	ifaces->sock = -1;
>-#ifdef DHCPv6
>-	if (local_family == AF_INET6) {
>-		if (ifaces->fp6)
>-			fclose(ifaces->fp6);
>-		ifaces->fp6 = NULL;
>-	}
>-#endif
>-}
> #else
> 
> /* 
>  * BSD support
>  * -----------
>  *
>- * FreeBSD, NetBSD, OpenBSD, and OS X all have the getifaddrs() 
>+ * FreeBSD, NetBSD, OpenBSD, OS X and Linux all have the getifaddrs() 
>  * function.
>  *
>  * The getifaddrs() man page describes the use.
>@@ -814,6 +433,8 @@ begin_iface_scan(struct iface_conf_list
>  */
> int
> next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
>+	size_t sa_len = 0;
>+
> 	if (ifaces->next == NULL) {
> 		*err = 0;
> 		return 0;
>@@ -825,8 +446,24 @@ next_iface(struct iface_info *info, int
> 		return 0;
> 	}
> 	strcpy(info->name, ifaces->next->ifa_name);
>-	memcpy(&info->addr, ifaces->next->ifa_addr, 
>-	       ifaces->next->ifa_addr->sa_len);
>+
>+	memset(&info->addr, 0 , sizeof(info->addr));
>+	/*
>+	 * getifaddrs() can on Linux with some interfaces like PPP or TEQL
>+	 * result in a record with no address (ifa_addr).
>+	 */
>+	if (ifaces->next->ifa_addr != NULL) {
>+/* Linux lacks the sa_len member in struct sockaddr. */
>+#if defined(__linux)
>+		if (ifaces->next->ifa_addr->sa_family == AF_INET)
>+			sa_len = sizeof(struct sockaddr_in);
>+		else if (ifaces->next->ifa_addr->sa_family == AF_INET6)
>+			sa_len = sizeof(struct sockaddr_in6);
>+#else
>+		sa_len = ifaces->next->ifa_addr->sa_len;
>+#endif
>+		memcpy(&info->addr, ifaces->next->ifa_addr, sa_len);
>+	}
> 	info->flags = ifaces->next->ifa_flags;
> 	ifaces->next = ifaces->next->ifa_next;
> 	*err = 0;

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Attachments on bug 803540: 573612