cifs.upcall: fix IPv6 addrs sent to upcall to have colon delimiters

Current kernels don't send IPv6 addresses with the colon delimiters, add
a routine to add them when they're not present.

Signed-off-by: Jeff Layton <jlayton@redhat.com>

diff --git a/client/cifs.upcall.c b/client/cifs.upcall.c
index c7a29bc5a2160e0bb6691ab9f2c3b384964dce84..c89df9cf63cdaed14d1333bf1425a3b97fe20256 100644 (file)
--- a/client/cifs.upcall.c
+++ b/client/cifs.upcall.c
@@ -296,18 +296,43 @@ cifs_resolver(const key_serial_t key, const char *key_descr)
        return 0;
 }
 
+/*
+ * Older kernels sent IPv6 addresses without colons. Well, at least
+ * they're fixed-length strings. Convert these addresses to have colon
+ * delimiters to make getaddrinfo happy.
+ */
+static void
+convert_inet6_addr(const char *from, char *to)
+{
+       int i = 1;
+
+       while (*from) {
+               *to++ = *from++;
+               if (!(i++ % 4) && *from)
+                       *to++ = ':';
+       }
+       *to = 0;
+}
+
 static int
-ip_to_fqdn(const char *ipaddr, char *host, size_t hostlen)
+ip_to_fqdn(const char *addrstr, char *host, size_t hostlen)
 {
        int rc;
        struct addrinfo hints = { .ai_flags = AI_NUMERICHOST };
        struct addrinfo *res;
+       const char *ipaddr = addrstr;
+       char converted[INET6_ADDRSTRLEN + 1];
+
+       if ((strlen(ipaddr) > INET_ADDRSTRLEN) && !strchr(ipaddr, ':')) {
+               convert_inet6_addr(ipaddr, converted);
+               ipaddr = converted;
+       }
 
        rc = getaddrinfo(ipaddr, NULL, &hints, &res);
        if (rc) {
-               syslog(LOG_DEBUG, "%s: failed to resolve %s to ipaddr: %s",
-                       __func__, ipaddr,
-                       rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
+               syslog(LOG_DEBUG, "%s: failed to resolve %s to "
+                       "ipaddr: %s", __func__, ipaddr,
+               rc == EAI_SYSTEM ? strerror(errno) : gai_strerror(rc));
                return rc;
        }