Merged #28761 (Linux interface discovery)

1 files changed, 21 insertions, 383 deletions

diff --git a/common/discover.c b/common/discover.c
index 8e7f6328..6824ec4b 100644
--- a/common/discover.c
+++ b/common/discover.c
@@ -373,392 +373,13 @@ 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[IF_LINE_LENGTH];
-	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[IF_LINE_LENGTH];
-	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;
-			}
-			strncpy(info->name, name, sizeof(info->name) - 1);
-
-#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));
-		strncpy(tmp.ifr_name, name, sizeof(tmp.ifr_name) - 1);
-		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));
-		strncpy(tmp.ifr_name, name, sizeof(tmp.ifr_name) - 1);
-		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[IF_LINE_LENGTH];
-	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;
-		}
-		strncpy(info->name, name, sizeof(info->name) - 1);
-
-#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));
-	strncpy(tmp.ifr_name, name, sizeof(tmp.ifr_name) - 1);
-	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) {
-	memset(info, 0, sizeof(struct iface_info));
-	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
+ * BSD/Linux support
  * -----------
  *
- * FreeBSD, NetBSD, OpenBSD, and OS X all have the getifaddrs() 
+ * FreeBSD, NetBSD, OpenBSD, OS X/macOS and Linux all have the getifaddrs() 
  * function.
  *
  * The getifaddrs() man page describes the use.
@@ -806,6 +427,8 @@ 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;
@@ -818,8 +441,23 @@ next_iface(struct iface_info *info, int *err, struct iface_conf_list *ifaces) {
 	}
 	memset(info, 0, sizeof(struct iface_info));
 	strncpy(info->name, ifaces->next->ifa_name, sizeof(info->name) - 1);
-	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;