util: Add functions to check if IP addresses is special

Added functions to check if given IP address is a special address
(broadcast, multicast...).

2 files changed, 70 insertions, 0 deletions

diff --git a/src/util/util.c b/src/util/util.c
index fb3bed146..9ab154db3 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -22,6 +22,7 @@
 #include <netdb.h>
 #include <poll.h>
 #include <sys/socket.h>
+#include <arpa/inet.h>
 
 #include "talloc.h"
 #include "util/util.h"
@@ -739,3 +740,59 @@ bool is_host_in_domain(const char *host, const char *domain)
 
     return false;
 }
+
+/* addr is in network order for both IPv4 and IPv6 versions */
+bool check_ipv4_addr(struct in_addr *addr, uint8_t flags)
+{
+    char straddr[INET_ADDRSTRLEN];
+
+    if (inet_ntop(AF_INET, addr, straddr, INET_ADDRSTRLEN) == NULL) {
+        DEBUG(SSSDBG_MINOR_FAILURE,
+              ("inet_ntop failed, won't log IP addresses\n"));
+        snprintf(straddr, INET_ADDRSTRLEN, "unknown");
+    }
+
+    if ((flags & SSS_NO_MULTICAST) && IN_MULTICAST(ntohl(addr->s_addr))) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Multicast IPv4 address %s\n", straddr));
+        return false;
+    } else if ((flags & SSS_NO_LOOPBACK)
+               && inet_netof(*addr) == IN_LOOPBACKNET) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Loopback IPv4 address %s\n", straddr));
+        return false;
+    } else if ((flags & SSS_NO_LINKLOCAL)
+               && (addr->s_addr & htonl(0xffff0000)) == htonl(0xa9fe0000)) {
+        /* 169.254.0.0/16 */
+        DEBUG(SSSDBG_FUNC_DATA, ("Link-local IPv4 address %s\n", straddr));
+        return false;
+    } else if ((flags & SSS_NO_BROADCAST)
+               && addr->s_addr == htonl(INADDR_BROADCAST)) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Broadcast IPv4 address %s\n", straddr));
+        return false;
+    }
+
+    return true;
+}
+
+bool check_ipv6_addr(struct in6_addr *addr, uint8_t flags)
+{
+    char straddr[INET6_ADDRSTRLEN];
+
+    if (inet_ntop(AF_INET6, addr, straddr, INET6_ADDRSTRLEN) == NULL) {
+        DEBUG(SSSDBG_MINOR_FAILURE,
+              ("inet_ntop failed, won't log IP addresses\n"));
+        snprintf(straddr, INET6_ADDRSTRLEN, "unknown");
+    }
+
+    if ((flags & SSS_NO_LINKLOCAL) && IN6_IS_ADDR_LINKLOCAL(addr)) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Link local IPv6 address %s\n", straddr));
+        return false;
+    } else if ((flags & SSS_NO_LOOPBACK) && IN6_IS_ADDR_LOOPBACK(addr)) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Loopback IPv6 address %s\n", straddr));
+        return false;
+    } else if ((flags & SSS_NO_MULTICAST) && IN6_IS_ADDR_MULTICAST(addr)) {
+        DEBUG(SSSDBG_FUNC_DATA, ("Multicast IPv6 address %s\n", straddr));
+        return false;
+    }
+
+    return true;
+}
diff --git a/src/util/util.h b/src/util/util.h
index 98b86e9db..3789c278c 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -37,6 +37,7 @@
 #include <pcre.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <arpa/inet.h>
 
 #include <talloc.h>
 #include <tevent.h>
@@ -438,6 +439,18 @@ errno_t check_and_open_readonly(const char *filename, int *fd, const uid_t uid,
                                enum check_file_type type);
 
 /* from util.c */
+#define SSS_NO_LINKLOCAL 0x01
+#define SSS_NO_LOOPBACK 0x02
+#define SSS_NO_MULTICAST 0x04
+#define SSS_NO_BROADCAST 0x08
+
+#define SSS_NO_SPECIAL \
+        (SSS_NO_LINKLOCAL|SSS_NO_LOOPBACK|SSS_NO_MULTICAST|SSS_NO_BROADCAST)
+
+/* These two functions accept addr in network order */
+bool check_ipv4_addr(struct in_addr *addr, uint8_t check);
+bool check_ipv6_addr(struct in6_addr *addr, uint8_t check);
+
 int split_on_separator(TALLOC_CTX *mem_ctx, const char *str,
                        const char sep, bool trim, bool skip_empty,
                        char ***_list, int *size);