]> The Tcpdump Group git mirrors - libpcap/blobdiff - gencode.c
Consolidate MAC-48 address matching code.
[libpcap] / gencode.c
index d36abbeb52d6197b48d64e83485b40ae98bd90cd..eed4863cbb7189c5730d1fb5ddec4969295dfb3e 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -679,13 +679,10 @@ static struct block *gen_hostop6(compiler_state_t *, struct in6_addr *,
     struct in6_addr *, int, u_int, u_int);
 #endif
 static struct block *gen_ahostop(compiler_state_t *, const uint8_t, int);
-static struct block *gen_mac48hostop(compiler_state_t *, const u_char *,
-    const int, const u_int, const u_int);
-static struct block *gen_ehostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_fhostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_thostop(compiler_state_t *, const u_char *, int);
 static struct block *gen_wlanhostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_ipfchostop(compiler_state_t *, const u_char *, int);
+static unsigned char is_mac48_linktype(const int);
+static struct block *gen_mac48host(compiler_state_t *, const u_char *,
+    const u_char, const char *);
 static struct block *gen_dnhostop(compiler_state_t *, bpf_u_int32, int);
 static struct block *gen_mpls_linktype(compiler_state_t *, bpf_u_int32);
 static struct block *gen_host(compiler_state_t *, bpf_u_int32, bpf_u_int32,
@@ -1069,6 +1066,7 @@ assert_maxval(compiler_state_t *cstate, const char *name,
 
 #define ERRSTR_802_11_ONLY_KW "'%s' is valid for 802.11 syntax only"
 #define ERRSTR_INVALID_QUAL "'%s' is not a valid qualifier for '%s'"
+#define ERRSTR_UNKNOWN_MAC48HOST "unknown Ethernet-like host '%s'"
 
 // Validate a port/portrange proto qualifier and map to an IP protocol number.
 static int
@@ -4472,85 +4470,24 @@ gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr,
        /* this order is important */
        memcpy(a, addr, sizeof(a));
        memcpy(m, mask, sizeof(m));
-       b1 = gen_mcmp(cstate, OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
-       b0 = gen_mcmp(cstate, OR_LINKPL, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
-       gen_and(b0, b1);
-       b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
-       gen_and(b0, b1);
-       b0 = gen_mcmp(cstate, OR_LINKPL, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
-       gen_and(b0, b1);
-       return b1;
-}
-#endif
-
-// MAC-48 address matching with the address offsets parametrised.
-static struct block *
-gen_mac48hostop(compiler_state_t *cstate, const u_char *addr, const int dir,
-    const u_int src_off, const u_int dst_off)
-{
-       struct block *b0, *b1;
-
-       switch (dir) {
-       case Q_SRC:
-               return gen_bcmp(cstate, OR_LINKHDR, src_off, 6, addr);
-
-       case Q_DST:
-               return gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, addr);
-
-       case Q_AND:
-               b0 = gen_mac48hostop(cstate, addr, Q_SRC, src_off, dst_off);
-               b1 = gen_mac48hostop(cstate, addr, Q_DST, src_off, dst_off);
-               gen_and(b0, b1);
-               return b1;
-
-       case Q_DEFAULT:
-       case Q_OR:
-               b0 = gen_mac48hostop(cstate, addr, Q_SRC, src_off, dst_off);
-               b1 = gen_mac48hostop(cstate, addr, Q_DST, src_off, dst_off);
-               gen_or(b0, b1);
-               return b1;
-
-       case Q_ADDR1:
-       case Q_ADDR2:
-       case Q_ADDR3:
-       case Q_ADDR4:
-       case Q_RA:
-       case Q_TA:
-               bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
-               /*NOTREACHED*/
+       b1 = NULL;
+       for (int i = 3; i >= 0; i--) {
+               // Same as the Q_IP case in gen_host().
+               if (m[i] == 0 && a[i] == 0)
+                       continue;
+               b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4 * i, BPF_W,
+                   ntohl(a[i]), ntohl(m[i]));
+               if (b1)
+                       gen_and(b0, b1);
+               else
+                       b1 = b0;
        }
-       abort();
-       /*NOTREACHED*/
-}
-
-static struct block *
-gen_ehostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-       return gen_mac48hostop(cstate, eaddr, dir, 6, 0);
-}
-
-/*
- * Like gen_ehostop, but for DLT_FDDI
- */
-static struct block *
-gen_fhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-       return gen_mac48hostop(cstate, eaddr, dir,
-           6 + 1 + cstate->pcap_fddipad,
-           0 + 1 + cstate->pcap_fddipad);
-}
-
-/*
- * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
- */
-static struct block *
-gen_thostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-       return gen_mac48hostop(cstate, eaddr, dir, 8, 2);
+       return b1 ? b1 : gen_true(cstate);
 }
+#endif
 
 /*
- * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and
+ * Like gen_mac48host(), but for DLT_IEEE802_11 (802.11 wireless LAN) and
  * various 802.11 + radio headers.
  */
 static struct block *
@@ -4930,17 +4867,6 @@ gen_wlanhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
        /*NOTREACHED*/
 }
 
-/*
- * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
- * (We assume that the addresses are IEEE 48-bit MAC addresses,
- * as the RFC states.)
- */
-static struct block *
-gen_ipfchostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-       return gen_mac48hostop(cstate, eaddr, dir, 10, 2);
-}
-
 /*
  * This is quite tricky because there may be pad bytes in front of the
  * DECNET header, and then there are two possible data packet formats that
@@ -5136,18 +5062,33 @@ gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
 
        case Q_IP:
                b0 = gen_linktype(cstate, ETHERTYPE_IP);
+               /*
+                * Belt and braces: if other code works correctly, any host
+                * bits are clear and mask == 0 means addr == 0.  In this case
+                * the call to gen_hostop() would produce an "always true"
+                * instruction block and ANDing it with the link type check
+                * would be a no-op.
+                */
+               if (mask == 0 && addr == 0)
+                       return b0;
                b1 = gen_hostop(cstate, addr, mask, dir, 12, 16);
                gen_and(b0, b1);
                return b1;
 
        case Q_RARP:
                b0 = gen_linktype(cstate, ETHERTYPE_REVARP);
+               // Same as for Q_IP above.
+               if (mask == 0 && addr == 0)
+                       return b0;
                b1 = gen_hostop(cstate, addr, mask, dir, 14, 24);
                gen_and(b0, b1);
                return b1;
 
        case Q_ARP:
                b0 = gen_linktype(cstate, ETHERTYPE_ARP);
+               // Same as for Q_IP above.
+               if (mask == 0 && addr == 0)
+                       return b0;
                b1 = gen_hostop(cstate, addr, mask, dir, 14, 24);
                gen_and(b0, b1);
                return b1;
@@ -5216,6 +5157,12 @@ gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
        case Q_DEFAULT:
        case Q_IPV6:
                b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
+               // Same as the Q_IP case in gen_host().
+               if (
+                       ! memcmp(mask, &in6addr_any, sizeof(struct in6_addr)) &&
+                       ! memcmp(addr, &in6addr_any, sizeof(struct in6_addr))
+               )
+                       return b0;
                b1 = gen_hostop6(cstate, addr, mask, dir, 8, 24);
                gen_and(b0, b1);
                return b1;
@@ -5269,6 +5216,104 @@ gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
 }
 #endif
 
+static unsigned char
+is_mac48_linktype(const int linktype)
+{
+       switch (linktype) {
+       case DLT_EN10MB:
+       case DLT_FDDI:
+       case DLT_IEEE802:
+       case DLT_IEEE802_11:
+       case DLT_IEEE802_11_RADIO:
+       case DLT_IEEE802_11_RADIO_AVS:
+       case DLT_IP_OVER_FC:
+       case DLT_NETANALYZER:
+       case DLT_NETANALYZER_TRANSPARENT:
+       case DLT_PPI:
+       case DLT_PRISM_HEADER:
+               return 1;
+       default:
+               return 0;
+       }
+}
+
+static struct block *
+gen_mac48host(compiler_state_t *cstate, const u_char *eaddr, const u_char dir,
+    const char *keyword)
+{
+       struct block *b1 = NULL;
+       u_int src_off, dst_off;
+
+       switch (cstate->linktype) {
+       case DLT_EN10MB:
+       case DLT_NETANALYZER:
+       case DLT_NETANALYZER_TRANSPARENT:
+               b1 = gen_prevlinkhdr_check(cstate);
+               src_off = 6;
+               dst_off = 0;
+               break;
+       case DLT_FDDI:
+               src_off = 6 + 1 + cstate->pcap_fddipad;
+               dst_off = 0 + 1 + cstate->pcap_fddipad;
+               break;
+       case DLT_IEEE802:
+               src_off = 8;
+               dst_off = 2;
+               break;
+       case DLT_IEEE802_11:
+       case DLT_PRISM_HEADER:
+       case DLT_IEEE802_11_RADIO_AVS:
+       case DLT_IEEE802_11_RADIO:
+       case DLT_PPI:
+               return gen_wlanhostop(cstate, eaddr, dir);
+       case DLT_IP_OVER_FC:
+               /*
+                * Assume that the addresses are IEEE 48-bit MAC addresses,
+                * as RFC 2625 states.
+                */
+               src_off = 10;
+               dst_off = 2;
+               break;
+       case DLT_SUNATM:
+               /*
+                * This is LLC-multiplexed traffic; if it were
+                * LANE, cstate->linktype would have been set to
+                * DLT_EN10MB.
+                */
+                /* FALLTHROUGH */
+       default:
+               fail_kw_on_dlt(cstate, keyword);
+       }
+
+       struct block *b0, *tmp;
+
+       switch (dir) {
+       case Q_SRC:
+               b0 = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+               break;
+       case Q_DST:
+               b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+               break;
+       case Q_AND:
+               tmp = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+               b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+               gen_and(tmp, b0);
+               break;
+       case Q_DEFAULT:
+       case Q_OR:
+               tmp = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+               b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+               gen_or(tmp, b0);
+               break;
+       default:
+               bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
+       }
+
+       if (b1 != NULL)
+               gen_and(b1, b0);
+       return b0;
+}
+
 #ifndef INET6
 /*
  * This primitive is non-directional by design, so the grammar does not allow
@@ -5287,42 +5332,7 @@ gen_gateway(compiler_state_t *cstate, const u_char *eaddr,
        case Q_IP:
        case Q_ARP:
        case Q_RARP:
-               switch (cstate->linktype) {
-               case DLT_EN10MB:
-               case DLT_NETANALYZER:
-               case DLT_NETANALYZER_TRANSPARENT:
-                       b1 = gen_prevlinkhdr_check(cstate);
-                       b0 = gen_ehostop(cstate, eaddr, Q_OR);
-                       if (b1 != NULL)
-                               gen_and(b1, b0);
-                       break;
-               case DLT_FDDI:
-                       b0 = gen_fhostop(cstate, eaddr, Q_OR);
-                       break;
-               case DLT_IEEE802:
-                       b0 = gen_thostop(cstate, eaddr, Q_OR);
-                       break;
-               case DLT_IEEE802_11:
-               case DLT_PRISM_HEADER:
-               case DLT_IEEE802_11_RADIO_AVS:
-               case DLT_IEEE802_11_RADIO:
-               case DLT_PPI:
-                       b0 = gen_wlanhostop(cstate, eaddr, Q_OR);
-                       break;
-               case DLT_IP_OVER_FC:
-                       b0 = gen_ipfchostop(cstate, eaddr, Q_OR);
-                       break;
-               case DLT_SUNATM:
-                       /*
-                        * This is LLC-multiplexed traffic; if it were
-                        * LANE, cstate->linktype would have been set to
-                        * DLT_EN10MB.
-                        */
-                        /* FALLTHROUGH */
-               default:
-                       bpf_error(cstate,
-                           "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
-               }
+               b0 = gen_mac48host(cstate, eaddr, Q_OR, "gateway");
                b1 = NULL;
                for (ai = alist; ai != NULL; ai = ai->ai_next) {
                        /*
@@ -5974,6 +5984,7 @@ gen_protochain(compiler_state_t *cstate, bpf_u_int32 v, int proto)
        switch (proto) {
        case Q_IP:
        case Q_IPV6:
+               assert_maxval(cstate, "protocol number", v, UINT8_MAX);
                break;
        case Q_DEFAULT:
                b0 = gen_protochain(cstate, v, Q_IP);
@@ -6180,12 +6191,10 @@ gen_protochain(compiler_state_t *cstate, bpf_u_int32 v, int proto)
         * A = P[X];
         * X = X + (P[X + 1] + 2) * 4;
         */
-       /* A = X */
-       s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
-       i++;
        /* A = P[X + packet head]; */
        s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
        s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
+       s[i - 1]->s.jt = s[i];
        i++;
        /* MEM[reg2] = A */
        s[i] = new_stmt(cstate, BPF_ST);
@@ -6714,7 +6723,8 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
        int proto = q.proto;
        int dir = q.dir;
        int tproto;
-       u_char *eaddr;
+       u_char *eaddrp;
+       u_char eaddr[6];
        bpf_u_int32 mask, addr;
        struct addrinfo *res, *res0;
        struct sockaddr_in *sin4;
@@ -6751,64 +6761,15 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
        case Q_DEFAULT:
        case Q_HOST:
                if (proto == Q_LINK) {
-                       switch (cstate->linktype) {
-
-                       case DLT_EN10MB:
-                       case DLT_NETANALYZER:
-                       case DLT_NETANALYZER_TRANSPARENT:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
-                                       bpf_error(cstate,
-                                           "unknown ether host '%s'", name);
-                               tmp = gen_prevlinkhdr_check(cstate);
-                               b = gen_ehostop(cstate, eaddr, dir);
-                               if (tmp != NULL)
-                                       gen_and(tmp, b);
-                               free(eaddr);
-                               return b;
-
-                       case DLT_FDDI:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
-                                       bpf_error(cstate,
-                                           "unknown FDDI host '%s'", name);
-                               b = gen_fhostop(cstate, eaddr, dir);
-                               free(eaddr);
-                               return b;
-
-                       case DLT_IEEE802:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
-                                       bpf_error(cstate,
-                                           "unknown token ring host '%s'", name);
-                               b = gen_thostop(cstate, eaddr, dir);
-                               free(eaddr);
-                               return b;
-
-                       case DLT_IEEE802_11:
-                       case DLT_PRISM_HEADER:
-                       case DLT_IEEE802_11_RADIO_AVS:
-                       case DLT_IEEE802_11_RADIO:
-                       case DLT_PPI:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
-                                       bpf_error(cstate,
-                                           "unknown 802.11 host '%s'", name);
-                               b = gen_wlanhostop(cstate, eaddr, dir);
-                               free(eaddr);
-                               return b;
-
-                       case DLT_IP_OVER_FC:
-                               eaddr = pcap_ether_hostton(name);
-                               if (eaddr == NULL)
-                                       bpf_error(cstate,
-                                           "unknown Fibre Channel host '%s'", name);
-                               b = gen_ipfchostop(cstate, eaddr, dir);
-                               free(eaddr);
-                               return b;
-                       }
-
-                       bpf_error(cstate, "only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
+                       const char *context = "link host NAME";
+                       if (! is_mac48_linktype(cstate->linktype))
+                               fail_kw_on_dlt(cstate, context);
+                       eaddrp = pcap_ether_hostton(name);
+                       if (eaddrp == NULL)
+                               bpf_error(cstate, ERRSTR_UNKNOWN_MAC48HOST, name);
+                       memcpy(eaddr, eaddrp, sizeof(eaddr));
+                       free(eaddrp);
+                       return gen_mac48host(cstate, eaddr, q.dir, context);
                } else if (proto == Q_DECNET) {
                        /*
                         * A long time ago on Ultrix libpcap supported
@@ -6964,9 +6925,13 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 
        case Q_GATEWAY:
 #ifndef INET6
-               eaddr = pcap_ether_hostton(name);
-               if (eaddr == NULL)
-                       bpf_error(cstate, "unknown ether host: %s", name);
+               if (! is_mac48_linktype(cstate->linktype))
+                       fail_kw_on_dlt(cstate, "gateway");
+               eaddrp = pcap_ether_hostton(name);
+               if (eaddrp == NULL)
+                       bpf_error(cstate, ERRSTR_UNKNOWN_MAC48HOST, name);
+               memcpy(eaddr, eaddrp, sizeof(eaddr));
+               free(eaddrp);
 
                res = pcap_nametoaddrinfo(name);
                cstate->ai = res;
@@ -6975,7 +6940,6 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
                b = gen_gateway(cstate, eaddr, res, proto);
                cstate->ai = NULL;
                freeaddrinfo(res);
-               free(eaddr);
                if (b == NULL)
                        bpf_error(cstate, "unknown host '%s'", name);
                return b;
@@ -7258,8 +7222,6 @@ gen_mcode6(compiler_state_t *cstate, const char *s, bpf_u_int32 masklen,
 struct block *
 gen_ecode(compiler_state_t *cstate, const char *s, struct qual q)
 {
-       struct block *b, *tmp;
-
        /*
         * Catch errors reported by us and routines below us, and return NULL
         * on an error.
@@ -7268,40 +7230,13 @@ gen_ecode(compiler_state_t *cstate, const char *s, struct qual q)
                return (NULL);
 
        if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
+               const char *context = "link host XX:XX:XX:XX:XX:XX";
+               if (! is_mac48_linktype(cstate->linktype))
+                       fail_kw_on_dlt(cstate, context);
                cstate->e = pcap_ether_aton(s);
                if (cstate->e == NULL)
                        bpf_error(cstate, "malloc");
-               switch (cstate->linktype) {
-               case DLT_EN10MB:
-               case DLT_NETANALYZER:
-               case DLT_NETANALYZER_TRANSPARENT:
-                       tmp = gen_prevlinkhdr_check(cstate);
-                       b = gen_ehostop(cstate, cstate->e, (int)q.dir);
-                       if (tmp != NULL)
-                               gen_and(tmp, b);
-                       break;
-               case DLT_FDDI:
-                       b = gen_fhostop(cstate, cstate->e, (int)q.dir);
-                       break;
-               case DLT_IEEE802:
-                       b = gen_thostop(cstate, cstate->e, (int)q.dir);
-                       break;
-               case DLT_IEEE802_11:
-               case DLT_PRISM_HEADER:
-               case DLT_IEEE802_11_RADIO_AVS:
-               case DLT_IEEE802_11_RADIO:
-               case DLT_PPI:
-                       b = gen_wlanhostop(cstate, cstate->e, (int)q.dir);
-                       break;
-               case DLT_IP_OVER_FC:
-                       b = gen_ipfchostop(cstate, cstate->e, (int)q.dir);
-                       break;
-               default:
-                       free(cstate->e);
-                       cstate->e = NULL;
-                       bpf_error(cstate, "ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
-                       /*NOTREACHED*/
-               }
+               struct block *b = gen_mac48host(cstate, cstate->e, q.dir, context);
                free(cstate->e);
                cstate->e = NULL;
                return (b);
@@ -7999,28 +7934,8 @@ gen_broadcast(compiler_state_t *cstate, int proto)
                case DLT_ARCNET_LINUX:
                        // ARCnet broadcast is [8-bit] destination address 0.
                        return gen_ahostop(cstate, 0, Q_DST);
-               case DLT_EN10MB:
-               case DLT_NETANALYZER:
-               case DLT_NETANALYZER_TRANSPARENT:
-                       b1 = gen_prevlinkhdr_check(cstate);
-                       b0 = gen_ehostop(cstate, ebroadcast, Q_DST);
-                       if (b1 != NULL)
-                               gen_and(b1, b0);
-                       return b0;
-               case DLT_FDDI:
-                       return gen_fhostop(cstate, ebroadcast, Q_DST);
-               case DLT_IEEE802:
-                       return gen_thostop(cstate, ebroadcast, Q_DST);
-               case DLT_IEEE802_11:
-               case DLT_PRISM_HEADER:
-               case DLT_IEEE802_11_RADIO_AVS:
-               case DLT_IEEE802_11_RADIO:
-               case DLT_PPI:
-                       return gen_wlanhostop(cstate, ebroadcast, Q_DST);
-               case DLT_IP_OVER_FC:
-                       return gen_ipfchostop(cstate, ebroadcast, Q_DST);
                }
-               fail_kw_on_dlt(cstate, "broadcast");
+               return gen_mac48host(cstate, ebroadcast, Q_DST, "broadcast");
                /*NOTREACHED*/
 
        case Q_IP: