Handle IPv4 mapped addresses

1 files changed, 21 insertions, 5 deletions

diff --git a/src/remoteip.c b/src/remoteip.c
index 9515df0..61bb015 100644
--- a/src/remoteip.c
+++ b/src/remoteip.c
@@ -27,6 +27,18 @@ str_is_ipv4(const char *addr)
         return (dot_count == 3);
 }
 
+#define PFXSTR_IPV4_MAPPED "::ffff:"
+#define PFXLEN_IPV4_MAPPED (sizeof PFXSTR_IPV4_MAPPED - 1)
+
+static int
+str_is_ipv4mapped(const char *addr)
+{
+        return strlen(addr) > PFXLEN_IPV4_MAPPED
+                && strncasecmp(PFXSTR_IPV4_MAPPED, addr, PFXLEN_IPV4_MAPPED)
+                    == 0
+                && str_is_ipv4(addr + PFXLEN_IPV4_MAPPED);
+}               
+
 /* Returns 1 if ADDR is a valid IPv6 address */
 static int
 str_is_ipv6(const char *addr)
@@ -120,7 +132,7 @@ static int
 str_to_cidr(char const *str, struct cidr *cidr)
 {
         int rc;
-        char *ipbuf;
+        char *ipbuf, *ipstart;
         union {
                 struct in_addr in;
                 struct in6_addr in6;
@@ -137,10 +149,14 @@ str_to_cidr(char const *str, struct cidr *cidr)
         ipbuf = xmalloc(len+1);
         memcpy(ipbuf, str, len);
         ipbuf[len] = 0;
-
-        if (str_is_ipv4(ipbuf))
+        ipstart = ipbuf;
+        
+        if (str_is_ipv4(ipstart))
+                cidr->family = AF_INET;
+        else if (str_is_ipv4mapped(ipstart)) {
                 cidr->family = AF_INET;
-        else if (str_is_ipv6(ipbuf))
+                ipstart += PFXLEN_IPV4_MAPPED;
+        } else if (str_is_ipv6(ipbuf))
                 cidr->family = AF_INET6;
         else {
                 free(ipbuf);
@@ -148,7 +164,7 @@ str_to_cidr(char const *str, struct cidr *cidr)
                 return -1;
         }
         
-        rc = inet_pton(cidr->family, ipbuf, &inaddr);
+        rc = inet_pton(cidr->family, ipstart, &inaddr);
         free(ipbuf);
 
         if (rc != 1) {