Rework address matching algorithm in SPF plugin.

diff --git a/src/plugins/spf.c b/src/plugins/spf.c
index d74f481c22d640c4f7e73f2cfccd4fa7fb208273..6bcb8626f9d53f7ea0390a1fd31c9bbd0455c1a4 100644 (file)
--- a/src/plugins/spf.c
+++ b/src/plugins/spf.c
@@ -188,11 +188,10 @@ static gboolean
 spf_check_element (struct spf_addr *addr, struct rspamd_task *task)
 {
        gboolean res = FALSE;
-       guint8 *s, *d, t, *buf;
+       guint8 *s, *d;
        gchar *spf_result;
-       gint af;
+       guint af, mask, bmask, addrlen;
        const gchar *spf_message, *spf_symbol;
-       guint nbits, addrlen;
        struct in_addr in4s;
        struct in6_addr in6s;
        GList *opts = NULL;
@@ -206,9 +205,6 @@ spf_check_element (struct spf_addr *addr, struct rspamd_task *task)
        if ((addr->data.normal.ipv6 && af == AF_INET6) ||
                (!addr->data.normal.ipv6 && af == AF_INET)) {
                d = rspamd_inet_address_get_radix_key (task->from_addr, &addrlen);
-               buf = g_alloca (addrlen);
-               memcpy (buf, d, addrlen);
-               d = buf;
 
                if (addr->data.normal.ipv6) {
                        memcpy (&in6s, &addr->data.normal.d.in6,
@@ -221,27 +217,27 @@ spf_check_element (struct spf_addr *addr, struct rspamd_task *task)
                        s = (guint8 *)&in4s;
                }
 
-               /* Move pointers to the less significant byte */
-               t = 0x1;
-               s += addrlen - 1;
-               d += addrlen - 1;
-               /* TODO: improve this cycle by masking by words */
-               for (nbits = 0;
-                       nbits < addrlen * CHAR_BIT - addr->data.normal.mask;
-                       nbits++) {
-                       /* Skip bits from the beginning as we know that data is in network byte order */
-                       if (nbits != 0 && nbits % 8 == 0) {
-                               /* Move pointer to the next byte */
-                               s--;
-                               d--;
-                               t = 0x1;
+               /* Compare the first bytes */
+               mask = addr->data.normal.mask;
+               bmask = mask / CHAR_BIT;
+               if (bmask > addrlen) {
+                       msg_info ("bad mask length: %d", mask);
+               }
+               else if (memcmp (s, d, bmask) == 0) {
+
+                       if (bmask * CHAR_BIT != mask) {
+                               /* Compare the remaining bits */
+                               s += bmask;
+                               d += bmask;
+                               mask = (0xff << (CHAR_BIT - (mask - bmask * 8))) & 0xff;
+                               if ((*s & mask) == (*d & mask)) {
+                                       res = TRUE;
+                               }
+                       }
+                       else {
+                               res = TRUE;
                        }
-                       *s |= t;
-                       *d |= t;
-                       t <<= 1;
                }
-
-               res = memcmp (d, s, addrlen);
        }
        else {
                if (addr->data.normal.addr_any) {