Handle very large -f files by rejecting them.

[tcpdump] / print-sl.c

diff --git a/print-sl.c b/print-sl.c
index 87daa47fa3fc2d203dabc6b27ff0f9f9ceda5d0a..301c86ce9a0873bac1e51ae077604c7bd81a4aa3 100644 (file)
--- a/print-sl.c
+++ b/print-sl.c
@@ -19,14 +19,16 @@
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */
 
+/* \summary: Compressed Serial Line Internet Protocol printer */
+
 #ifdef HAVE_CONFIG_H
 #include "config.h"
 #endif
 
-#include <tcpdump-stdinc.h>
+#include <netdissect-stdinc.h>
 
-#include "interface.h"
-#include "extract.h"                   /* must come after interface.h */
+#include "netdissect.h"
+#include "extract.h"
 
 #include "ip.h"
 #include "tcp.h"
@@ -50,8 +52,8 @@ static const char tstr[] = "[|slip]";
 static u_int lastlen[2][256];
 static u_int lastconn = 255;
 
-static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int);
-static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int);
+static int sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int);
+static int compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int);
 
 u_int
 sl_if_print(netdissect_options *ndo,
@@ -66,12 +68,21 @@ sl_if_print(netdissect_options *ndo,
                return (caplen);
        }
 
+       caplen -= SLIP_HDRLEN;
        length -= SLIP_HDRLEN;
 
        ip = (const struct ip *)(p + SLIP_HDRLEN);
 
        if (ndo->ndo_eflag)
-               sliplink_print(ndo, p, ip, length);
+               if (sliplink_print(ndo, p, ip, length) == -1) {
+                       ND_PRINT((ndo, "%s", tstr));
+                       return (caplen + SLIP_HDRLEN);
+       }
+
+       if (caplen < 1 || length < 1) {
+               ND_PRINT((ndo, "%s", tstr));
+               return (caplen + SLIP_HDRLEN);
+       }
 
        switch (IP_V(ip)) {
        case 4:
@@ -114,7 +125,7 @@ sl_bsdos_if_print(netdissect_options *ndo,
        return (SLIP_HDRLEN);
 }
 
-static void
+static int
 sliplink_print(netdissect_options *ndo,
                register const u_char *p, register const struct ip *ip,
                register u_int length)
@@ -123,8 +134,21 @@ sliplink_print(netdissect_options *ndo,
        u_int hlen;
 
        dir = p[SLX_DIR];
-       ND_PRINT((ndo, dir == SLIPDIR_IN ? "I " : "O "));
+       switch (dir) {
+
+       case SLIPDIR_IN:
+               ND_PRINT((ndo, "I "));
+               break;
 
+       case SLIPDIR_OUT:
+               ND_PRINT((ndo, "O "));
+               break;
+
+       default:
+               ND_PRINT((ndo, "Invalid direction %d ", dir));
+               dir = -1;
+               break;
+       }
        if (ndo->ndo_nflag) {
                /* XXX just dump the header */
                register int i;
@@ -132,7 +156,7 @@ sliplink_print(netdissect_options *ndo,
                for (i = SLX_CHDR; i < SLX_CHDR + CHDR_LEN - 1; ++i)
                        ND_PRINT((ndo, "%02x.", p[i]));
                ND_PRINT((ndo, "%02x: ", p[SLX_CHDR + CHDR_LEN - 1]));
-               return;
+               return 0;
        }
        switch (p[SLX_CHDR] & 0xf0) {
 
@@ -147,20 +171,34 @@ sliplink_print(netdissect_options *ndo,
                 * has restored the IP header copy to IPPROTO_TCP.
                 */
                lastconn = ((const struct ip *)&p[SLX_CHDR])->ip_p;
+               ND_PRINT((ndo, "utcp %d: ", lastconn));
+               if (dir == -1) {
+                       /* Direction is bogus, don't use it */
+                       return 0;
+               }
+               ND_TCHECK(*ip);
                hlen = IP_HL(ip);
+               ND_TCHECK(*((const struct tcphdr *)&((const int *)ip)[hlen]));
                hlen += TH_OFF((const struct tcphdr *)&((const int *)ip)[hlen]);
                lastlen[dir][lastconn] = length - (hlen << 2);
-               ND_PRINT((ndo, "utcp %d: ", lastconn));
                break;
 
        default:
+               if (dir == -1) {
+                       /* Direction is bogus, don't use it */
+                       return 0;
+               }
                if (p[SLX_CHDR] & TYPE_COMPRESSED_TCP) {
-                       compressed_sl_print(ndo, &p[SLX_CHDR], ip,
-                           length, dir);
+                       if (compressed_sl_print(ndo, &p[SLX_CHDR], ip,
+                                               length, dir) == -1)
+                               goto trunc;
                        ND_PRINT((ndo, ": "));
                } else
                        ND_PRINT((ndo, "slip-%d!: ", p[SLX_CHDR]));
        }
+       return 0;
+trunc:
+       return -1;
 }
 
 static const u_char *
@@ -194,7 +232,7 @@ print_sl_winchange(netdissect_options *ndo,
        return (cp);
 }
 
-static void
+static int
 compressed_sl_print(netdissect_options *ndo,
                     const u_char *chdr, const struct ip *ip,
                     u_int length, int dir)
@@ -240,8 +278,13 @@ compressed_sl_print(netdissect_options *ndo,
         * 'cp - chdr' is the length of the compressed header.
         * 'length - hlen' is the amount of data in the packet.
         */
+       ND_TCHECK(*ip);
        hlen = IP_HL(ip);
+       ND_TCHECK(*((const struct tcphdr *)&((const int32_t *)ip)[hlen]));
        hlen += TH_OFF((const struct tcphdr *)&((const int32_t *)ip)[hlen]);
        lastlen[dir][lastconn] = length - (hlen << 2);
        ND_PRINT((ndo, " %d (%ld)", lastlen[dir][lastconn], (long)(cp - chdr)));
+       return 0;
+trunc:
+       return -1;
 }