xt_ipp2p: add helper for matching "\r\n"

There are repeated checks that:

	pkt[x] == 0x0d && pkt[x + 1] == 0x0a

Replace them with ``iscrlf(&pkt[x])`` function calls.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>

diff --git a/extensions/xt_ipp2p.c b/extensions/xt_ipp2p.c
index d2e29706998a48a7e7b617400acc2cc2a8ec32c0..1ab1342f91ef28a3d6ab8583b58e22038efd4a18 100644 (file)
--- a/extensions/xt_ipp2p.c
+++ b/extensions/xt_ipp2p.c
@@ -39,6 +39,11 @@ struct ipp2p_result_printer {
        void (*print)(const union nf_inet_addr *, short, const union nf_inet_addr *, short, bool, unsigned int);
 };
 
+static bool iscrlf(const unsigned char *str)
+{
+       return str[0] == '\r' && str[1] == '\n';
+}
+
 static void
 print_result(const struct ipp2p_result_printer *rp, bool result,
              unsigned int hlen)
@@ -518,7 +523,7 @@ search_winmx(const unsigned char *payload, const unsigned int plen)
 static unsigned int
 search_apple(const unsigned char *payload, const unsigned int plen)
 {
-       if (plen > 7 && payload[6] == 0x0d && payload[7] == 0x0a &&
+       if (plen > 7 && iscrlf(&payload[6]) &&
            memcmp(payload, "ajprot", 6) == 0)
                return IPP2P_APPLE * 100;
 
@@ -574,7 +579,7 @@ search_kazaa(const unsigned char *payload, const unsigned int plen)
 {
        if (plen < 13)
                return 0;
-       if (payload[plen-2] == 0x0d && payload[plen-1] == 0x0a &&
+       if (iscrlf(&payload[plen-2]) &&
            memcmp(payload, "GET /.hash=", 11) == 0)
                return IPP2P_DATA_KAZAA * 100;
 
@@ -587,7 +592,7 @@ search_gnu(const unsigned char *payload, const unsigned int plen)
 {
        if (plen < 11)
                return 0;
-       if (payload[plen-2] == 0x0d && payload[plen-1] == 0x0a) {
+       if (iscrlf(&payload[plen-2])) {
                if (memcmp(payload, "GET /get/", 9) == 0)
                        return IPP2P_DATA_GNU * 100 + 1;
                if (plen >= 15 && memcmp(payload, "GET /uri-res/", 13) == 0)
@@ -602,7 +607,7 @@ search_all_gnu(const unsigned char *payload, const unsigned int plen)
 {
        if (plen < 11)
                return 0;
-       if (payload[plen-2] == 0x0d && payload[plen-1] == 0x0a) {
+       if (iscrlf(&payload[plen-2])) {
                if (plen >= 19 && memcmp(payload, "GNUTELLA CONNECT/", 17) == 0)
                        return IPP2P_GNU * 100 + 1;
                if (memcmp(payload, "GNUTELLA/", 9) == 0)
@@ -614,8 +619,7 @@ search_all_gnu(const unsigned char *payload, const unsigned int plen)
                        unsigned int c;
 
                        for (c = 0; c < plen - 22; ++c)
-                               if (payload[c] == 0x0d &&
-                                   payload[c+1] == 0x0a &&
+                               if (iscrlf(&payload[c]) &&
                                    (memcmp(&payload[c+2], "X-Gnutella-", 11) == 0 ||
                                    memcmp(&payload[c+2], "X-Queue:", 8) == 0))
                                        return IPP2P_GNU * 100 + 3;
@@ -634,8 +638,7 @@ search_all_kazaa(const unsigned char *payload, const unsigned int plen)
        if (plen < 7)
                /* too short for anything we test for - early bailout */
                return 0;
-
-       if (payload[plen-2] != 0x0d || payload[plen-1] != 0x0a)
+       if (!iscrlf(&payload[plen-2]))
                return 0;
 
        if (memcmp(payload, "GIVE ", 5) == 0)
@@ -651,9 +654,7 @@ search_all_kazaa(const unsigned char *payload, const unsigned int plen)
        end = plen - 18;
        rem = plen - 5;
        for (c = 5; c < end; ++c, --rem) {
-               if (payload[c] != 0x0d)
-                       continue;
-               if (payload[c+1] != 0x0a)
+               if (!iscrlf(&payload[c]))
                        continue;
                if (rem >= 18 &&
                    memcmp(&payload[c+2], "X-Kazaa-Username: ", 18) == 0)
@@ -769,8 +770,8 @@ static unsigned int
 search_xdcc(const unsigned char *payload, const unsigned int plen)
 {
        /* search in small packets only */
-       if (plen > 20 && plen < 200 && payload[plen-1] == 0x0a &&
-           payload[plen-2] == 0x0d && memcmp(payload, "PRIVMSG ", 8) == 0)
+       if (plen > 20 && plen < 200 && iscrlf(&payload[plen-2]) &&
+           memcmp(payload, "PRIVMSG ", 8) == 0)
        {
                uint16_t x = 10;
                const uint16_t end = plen - 13;