]> The Tcpdump Group git mirrors - tcpdump/blobdiff - print-nflog.c
Merge pull request #492 from vel21ripn/nflog-print
[tcpdump] / print-nflog.c
index 8a6ce4a50a60b8dfc81018394afcd3cf00a47234..9ed283c330937b4f8e11300eacc63dc165b760b8 100644 (file)
  * DAMAGE.
  */
 
+/* \summary: DLT_NFLOG printer */
+
 #ifdef HAVE_CONFIG_H
-#include "config.h"
+#include <config.h>
 #endif
 
-#include <netdissect-stdinc.h>
+#include "netdissect-stdinc.h"
 
 #include "netdissect.h"
+#include "extract.h"
+
+#ifdef DLT_NFLOG
+
+/*
+ * Structure of an NFLOG header and TLV parts, as described at
+ * https://www.tcpdump.org/linktypes/LINKTYPE_NFLOG.html
+ *
+ * The NFLOG header is big-endian.
+ *
+ * The TLV length and type are in host byte order.  The value is either
+ * big-endian or is an array of bytes in some externally-specified byte
+ * order (text string, link-layer address, link-layer header, packet
+ * data, etc.).
+ */
+typedef struct nflog_hdr {
+       nd_uint8_t      nflog_family;           /* address family */
+       nd_uint8_t      nflog_version;          /* version */
+       nd_uint16_t     nflog_rid;              /* resource ID */
+} nflog_hdr_t;
+
+typedef struct nflog_tlv {
+       nd_uint16_t     tlv_length;             /* tlv length */
+       nd_uint16_t     tlv_type;               /* tlv type */
+       /* value follows this */
+} nflog_tlv_t;
+
+typedef struct nflog_packet_hdr {
+       nd_uint16_t     hw_protocol;    /* hw protocol */
+       nd_uint8_t      hook;           /* netfilter hook */
+       nd_byte         pad[1];         /* padding to 32 bits */
+} nflog_packet_hdr_t;
+
+typedef struct nflog_hwaddr {
+       nd_uint16_t     hw_addrlen;     /* address length */
+       nd_byte         pad[2];         /* padding to 32-bit boundary */
+       nd_byte         hw_addr[8];     /* address, up to 8 bytes */
+} nflog_hwaddr_t;
 
-#if defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H)
-#include <pcap/nflog.h>
+typedef struct nflog_timestamp {
+       nd_uint64_t     sec;
+       nd_uint64_t     usec;
+} nflog_timestamp_t;
+
+/*
+ * TLV types.
+ */
+#define NFULA_PACKET_HDR               1       /* nflog_packet_hdr_t */
+#define NFULA_MARK                     2       /* packet mark from skbuff */
+#define NFULA_TIMESTAMP                        3       /* nflog_timestamp_t for skbuff's time stamp */
+#define NFULA_IFINDEX_INDEV            4       /* ifindex of device on which packet received (possibly bridge group) */
+#define NFULA_IFINDEX_OUTDEV           5       /* ifindex of device on which packet transmitted (possibly bridge group) */
+#define NFULA_IFINDEX_PHYSINDEV                6       /* ifindex of physical device on which packet received (not bridge group) */
+#define NFULA_IFINDEX_PHYSOUTDEV       7       /* ifindex of physical device on which packet transmitted (not bridge group) */
+#define NFULA_HWADDR                   8       /* nflog_hwaddr_t for hardware address */
+#define NFULA_PAYLOAD                  9       /* packet payload */
+#define NFULA_PREFIX                   10      /* text string - null-terminated, count includes NUL */
+#define NFULA_UID                      11      /* UID owning socket on which packet was sent/received */
+#define NFULA_SEQ                      12      /* sequence number of packets on this NFLOG socket */
+#define NFULA_SEQ_GLOBAL               13      /* sequence number of pakets on all NFLOG sockets */
+#define NFULA_GID                      14      /* GID owning socket on which packet was sent/received */
+#define NFULA_HWTYPE                   15      /* ARPHRD_ type of skbuff's device */
+#define NFULA_HWHEADER                 16      /* skbuff's MAC-layer header */
+#define NFULA_HWLEN                    17      /* length of skbuff's MAC-layer header */
 
 static const struct tok nflog_values[] = {
        { AF_INET,              "IPv4" },
@@ -44,24 +107,25 @@ static const struct tok nflog_values[] = {
        { 0,                    NULL }
 };
 
-static inline void
+static void
 nflog_hdr_print(netdissect_options *ndo, const nflog_hdr_t *hdr, u_int length)
 {
-       ND_PRINT((ndo, "version %d, resource ID %d", hdr->nflog_version, ntohs(hdr->nflog_rid)));
+       ND_PRINT("version %u, resource ID %u",
+           GET_U_1(hdr->nflog_version), GET_BE_U_2(hdr->nflog_rid));
 
        if (!ndo->ndo_qflag) {
-               ND_PRINT((ndo,", family %s (%d)",
-                                                 tok2str(nflog_values, "Unknown",
-                                                                 hdr->nflog_family),
-                                                 hdr->nflog_family));
+               ND_PRINT(", family %s (%u)",
+                        tok2str(nflog_values, "Unknown",
+                                GET_U_1(hdr->nflog_family)),
+                        GET_U_1(hdr->nflog_family));
                } else {
-               ND_PRINT((ndo,", %s",
-                                                 tok2str(nflog_values,
-                                                                 "Unknown NFLOG (0x%02x)",
-                                                                 hdr->nflog_family)));
+               ND_PRINT(", %s",
+                        tok2str(nflog_values,
+                                "Unknown NFLOG (0x%02x)",
+                        GET_U_1(hdr->nflog_family)));
                }
 
-       ND_PRINT((ndo, ", length %u: ", length));
+       ND_PRINT(", length %u: ", length);
 }
 
 static char *hook_names[] = { "PRE","IN","FWD","OUT","POST" };
@@ -76,7 +140,6 @@ nflog_if_print(netdissect_options *ndo,
                           const struct pcap_pkthdr *h, const u_char *p)
 {
        const nflog_hdr_t *hdr = (const nflog_hdr_t *)p;
-       const nflog_tlv_t *tlv;
        uint16_t size;
        uint16_t hw_hdrlen = 0;
        uint16_t hw_addrlen = 0;
@@ -84,13 +147,13 @@ nflog_if_print(netdissect_options *ndo,
        u_int caplen = h->caplen;
        u_int length = h->len;
 
-       if (caplen < (int) sizeof(nflog_hdr_t) || length < (int) sizeof(nflog_hdr_t)) {
-               ND_PRINT((ndo, "[|nflog]"));
-               return h_size;
-       }
+       ndo->ndo_protocol = "nflog_if";
+       if (caplen < sizeof(nflog_hdr_t))
+               goto trunc;
 
-       if (!(hdr->nflog_version) == 0) {
-               ND_PRINT((ndo, "version %u (unknown)", hdr->nflog_version));
+       ND_TCHECK_SIZE(hdr);
+       if (GET_U_1(hdr->nflog_version) != 0) {
+               ND_PRINT("version %u (unknown)", GET_U_1(hdr->nflog_version));
                return h_size;
        }
 
@@ -102,33 +165,27 @@ nflog_if_print(netdissect_options *ndo,
        caplen -= sizeof(nflog_hdr_t);
 
        while (length > 0) {
+               const nflog_tlv_t *tlv;
+
                /* We have some data.  Do we have enough for the TLV header? */
-               if (caplen < sizeof(nflog_tlv_t) || length < sizeof(nflog_tlv_t)) {
-                       /* No. */
-                       ND_PRINT((ndo, "[|nflog]"));
-                       return h_size;
-               }
+               if (caplen < sizeof(nflog_tlv_t))
+                       goto trunc;     /* No. */
 
                tlv = (const nflog_tlv_t *) p;
-               size = tlv->tlv_length;
+               ND_TCHECK_SIZE(tlv);
+               size = GET_HE_U_2(tlv->tlv_length);
                if (size % 4 != 0)
                        size += 4 - size % 4;
 
                /* Is the TLV's length less than the minimum? */
-               if (size < sizeof(nflog_tlv_t)) {
-                       /* Yes. Give up now. */
-                       ND_PRINT((ndo, "[|nflog]"));
-                       return h_size;
-               }
+               if (size < sizeof(nflog_tlv_t))
+                       goto trunc;     /* Yes. Give up now. */
 
                /* Do we have enough data for the full TLV? */
-               if (caplen < size || length < size) {
-                       /* No. */
-                       ND_PRINT((ndo, "[|nflog]"));
-                       return h_size;
-               }
+               if (caplen < size)
+                       goto trunc;     /* No. */
 
-               if (tlv->tlv_type == NFULA_PAYLOAD) {
+               if (GET_HE_U_2(tlv->tlv_type) == NFULA_PAYLOAD) {
                        /*
                         * This TLV's data is the packet payload.
                         * Skip past the TLV header, and break out
@@ -223,7 +280,7 @@ nflog_if_print(netdissect_options *ndo,
                caplen -= size;
        }
 
-       switch (hdr->nflog_family) {
+       switch (GET_U_1(hdr->nflog_family)) {
 
        case AF_INET:
                ip_print(ndo, p, length);
@@ -245,7 +302,10 @@ nflog_if_print(netdissect_options *ndo,
                break;
        }
 
+       return h_size;
+trunc:
+       nd_print_trunc(ndo);
        return h_size;
 }
 
-#endif /* defined(DLT_NFLOG) && defined(HAVE_PCAP_NFLOG_H) */
+#endif /* DLT_NFLOG */