From c09dd24a7d63988e0acef7d033bd3e088fc005c0 Mon Sep 17 00:00:00 2001

From: Jiri Popelka <jpopelka@redhat.com>

Date: Thu, 24 Jan 2013 12:39:50 +0100

Subject: [PATCH] Linux interface discovery

Use the same discovery code as for *BSD and OS X,

i.e. the getifaddrs() function.

---

 common/discover.c | 398 +++---------------------------------------------------

 1 file changed, 17 insertions(+), 381 deletions(-)

diff --git a/common/discover.c b/common/discover.c

index 1d84219..f2a8f6d 100644

--- a/common/discover.c

+++ b/common/discover.c

@@ -379,391 +379,13 @@ end_iface_scan(struct iface_conf_list *ifaces) {

 	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", "r");

-	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) {

-		ifaces->fp6 = fopen("/proc/net/if_inet6", "r");

-		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;

-		}

-	}

-#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)) {

-		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) {

-		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.

@@ -811,6 +433,8 @@ begin_iface_scan(struct iface_conf_list *ifaces) {

  */

 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;

@@ -822,8 +446,20 @@ next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {

 		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));

+

+	if (ifaces->next->ifa_addr != NULL) {

+#ifdef HAVE_SA_LEN

+		sa_len = ifaces->next->ifa_addr->sa_len;

+#else

+		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);

+#endif

+		memcpy(&info->addr, ifaces->next->ifa_addr, sa_len);

+	}

 	info->flags = ifaces->next->ifa_flags;

 	ifaces->next = ifaces->next->ifa_next;

 	*err = 0;

-- 

1.8.1