hints: fix reverse IPv6 hints

The length was halved, mixed ">" vs. ">>", etc.

diff --git a/modules/hints/hints.c b/modules/hints/hints.c
index 74c9e7f3c8f8071e0b7f90aa8515b1f1a4f9ed2c..c64805276a2b7d5d3d3674e7f9cf8f484251ad8b 100644 (file)
--- a/modules/hints/hints.c
+++ b/modules/hints/hints.c
@@ -185,50 +185,53 @@ static const knot_rdata_t * addr2rdata(const char *addr) {
 }
 
 /** @warning _NOT_ thread-safe; returns a pointer to static data! */
-static const knot_dname_t * raw_addr2reverse(const uint8_t *raw_addr, int family) 
+static const knot_dname_t * raw_addr2reverse(const union inaddr *addr)
 {
-       char reverse_addr[KNOT_DNAME_MAXLEN];
-       static knot_dname_t dname[KNOT_DNAME_MAXLEN];
-       if (family == AF_INET) {
-               snprintf(reverse_addr, KNOT_DNAME_MAXLEN, "%d.%d.%d.%d.in-addr.arpa.",
-                        raw_addr[3], raw_addr[2], raw_addr[1], raw_addr[0]
-               );
+       #define REV_MAXLEN (4*16 + 16 /* the suffix, terminator, etc. */)
+       char reverse_addr[REV_MAXLEN];
+       static knot_dname_t dname[REV_MAXLEN];
+       #undef REV_MAXLEN
+
+       const uint8_t *raw_addr = (const uint8_t *)kr_inaddr(&addr->ip);
+       if (addr->ip.sa_family == AF_INET) {
+               snprintf(reverse_addr, sizeof(reverse_addr),
+                        "%d.%d.%d.%d.in-addr.arpa.",
+                        raw_addr[3], raw_addr[2], raw_addr[1], raw_addr[0]);
+       } else if (addr->ip.sa_family == AF_INET6) {
+               char *ra_it = reverse_addr;
+               for (int i = 15; i >= 0; --i) {
+                       ssize_t free_space = reverse_addr + sizeof(reverse_addr) - ra_it;
+                       int written = snprintf(ra_it, free_space, "%x.%x.",
+                                               raw_addr[i] & 0x0f, raw_addr[i] >> 4);
+                       if (written >= free_space) {
+                               assert(false);
+                               return NULL;
+                       }
+                       ra_it += written;
+               }
+               ssize_t free_space = reverse_addr + sizeof(reverse_addr) - ra_it;
+               if (snprintf(ra_it, free_space, "ip6.arpa.") >= free_space) {
+                       return NULL;
+               }
        } else {
-               snprintf(reverse_addr, KNOT_DNAME_MAXLEN,
-                        "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.in-addr6.arpa.",
-                        raw_addr[7] & 0x0f, (raw_addr[7] > 4),
-                        raw_addr[6] & 0x0f, (raw_addr[6] > 4),
-                        raw_addr[5] & 0x0f, (raw_addr[5] > 4),
-                        raw_addr[4] & 0x0f, (raw_addr[4] > 4),
-                        raw_addr[3] & 0x0f, (raw_addr[3] > 4),
-                        raw_addr[2] & 0x0f, (raw_addr[2] > 4),
-                        raw_addr[1] & 0x0f, (raw_addr[1] > 4),
-                        raw_addr[0] & 0x0f, (raw_addr[0] > 4)
-               );
+               return NULL;
        }
        
        if (!knot_dname_from_str(dname, reverse_addr, sizeof(dname))) {
                return NULL;
        }
-       if (knot_dname_to_lower(dname) != KNOT_EOK) {
-               return NULL;
-       }
        return dname;
 }
 
 /** @warning _NOT_ thread-safe; returns a pointer to static data! */
-static const knot_dname_t * addr2reverse(const char *addr) 
+static const knot_dname_t * addr2reverse(const char *addr)
 {
        /* Parse address string */
        struct sockaddr_storage ss;
        if (parse_addr_str(&ss, addr) != 0) {
                return NULL;
        }
-       
-       // Convert ip address to reverse order
-       const uint8_t *raw_addr = (const uint8_t *)kr_inaddr((struct sockaddr *)&ss);
-       int family = kr_inaddr_family((struct sockaddr *)&ss);
-       return raw_addr2reverse(raw_addr, family);
+       return raw_addr2reverse((union inaddr *)(struct sockaddr *)&ss);
 }
 
 static int add_pair(struct kr_zonecut *hints, const char *name, const char *addr)
@@ -301,8 +304,7 @@ static int del_pair(struct hints_data *data, const char *name, const char *addr)
                uint8_t *addr = pack_head(*addr_set);
                while (addr != pack_tail(*addr_set)) {
                        void *addr_val = pack_obj_val(addr);
-                       int family = pack_obj_len(addr) == kr_family_len(AF_INET) ? AF_INET : AF_INET6;
-                       const knot_dname_t *reverse_key = raw_addr2reverse(addr_val, family);
+                       const knot_dname_t *reverse_key = raw_addr2reverse((union inaddr *)addr_val);
                        if (reverse_key != NULL) {
                                kr_zonecut_del(&data->reverse_hints, reverse_key, ptr_rdata);
                        }