[RFC LIBPCAP PATCH 1/1] Implement DLT_LINUX_SLL2

[Petr Vorel <pvorel () suse cz>]

From: Petr Vorel <petr.vorel () gmail com>

Implements: GH the-tcpdump-group/libpcap#127

Signed-off-by: Petr Vorel <petr.vorel () gmail com>
Signed-off-by: Petr Vorel <pvorel () suse cz>
---
 INSTALL.md       |  2 +-
 cmakeconfig.h.in |  3 +++
 config.h.in      |  4 ++++
 configure        | 20 ++++++++++++++++++++
 configure.ac     | 10 ++++++++++
 gencode.c        |  3 +++
 pcap-common.c    |  1 +
 pcap-linux.c     | 12 ++++++++++++
 pcap.c           |  4 ++++
 pcap/sll.h       | 21 +++++++++++++++++++--
 10 files changed, 77 insertions(+), 3 deletions(-)

diff --git a/INSTALL.md b/INSTALL.md
index 96c87a2c..47daa52d 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -308,7 +308,7 @@ pcap/bluetooth.h - public definition of DLT_BLUETOOTH_HCI_H4_WITH_PHDR header
 pcap/bpf.h     - BPF definitions
 pcap/namedb.h  - public libpcap name database definitions
 pcap/pcap.h    - public libpcap definitions
-pcap/sll.h     - public definition of DLT_LINUX_SLL header
+pcap/sll.h     - public definition of DLT_LINUX_SLL and DLT_LINUX_SLL2 headers
 pcap/usb.h     - public definition of DLT_USB header
 pcap-bpf.c     - BSD Packet Filter support
 pcap-bpf.h     - header for backwards compatibility
diff --git a/cmakeconfig.h.in b/cmakeconfig.h.in
index 6760cec7..216ea92d 100644
--- a/cmakeconfig.h.in
+++ b/cmakeconfig.h.in
@@ -360,6 +360,9 @@
 /* define on AIX to get certain functions */
 #cmakedefine _SUN 1
 
+/* enable new LINKTYPE_LINUX_SLL2 capture support on Linux instead of legacy LINKTYPE_LINUX_SLL */
+#cmakedefine PCAP_SUPPORT_SLL_V2 1
+
 #if 0
 /* on sinix */
 #cmakedefine sinix 1
diff --git a/config.h.in b/config.h.in
index b1a20a44..19dd284f 100644
--- a/config.h.in
+++ b/config.h.in
@@ -325,6 +325,10 @@
 /* target host supports RDMA sniffing */
 #undef PCAP_SUPPORT_RDMASNIFF
 
+/* enable new LINKTYPE_LINUX_SLL2 capture support on Linux instead of legacy
+   LINKTYPE_LINUX_SLL */
+#undef PCAP_SUPPORT_SLL_V2
+
 /* target host supports USB sniffing */
 #undef PCAP_SUPPORT_USB
 
diff --git a/configure b/configure
index 95e7f480..1fa60cde 100755
--- a/configure
+++ b/configure
@@ -623,6 +623,7 @@ ac_subst_vars='LTLIBOBJS
 INSTALL_DATA
 INSTALL_SCRIPT
 INSTALL_PROGRAM
+PCAP_SUPPORT_SLL_V2
 RDMA_SRC
 PCAP_SUPPORT_RDMASNIFF
 DBUS_SRC
@@ -764,6 +765,7 @@ enable_netmap
 enable_bluetooth
 enable_dbus
 enable_rdma
+enable_sll_v2
 '
       ac_precious_vars='build_alias
 host_alias
@@ -1411,6 +1413,9 @@ Optional Features:
                           support available]
   --enable-rdma           enable RDMA capture support [default=yes, if support
                           available]
+  --enable-sll-v2         enable new LINKTYPE_LINUX_SLL2 capture support on
+                          Linux instead of legacy LINKTYPE_LINUX_SLL
+                          [default=yes]
 
 Optional Packages:
   --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
@@ -10647,6 +10652,21 @@ fi
 
 
 
+fi
+
+# Check whether --enable-sll-v2 was given.
+if test "${enable_sll_v2+set}" = set; then :
+  enableval=$enable_sll_v2;
+else
+  enable_sll_v2=yes
+fi
+
+
+if test "x$enable_sll_v2" != "xno" ; then
+
+$as_echo "#define PCAP_SUPPORT_SLL_V2 1" >>confdefs.h
+
+
 fi
 
 # Find a good install program.  We prefer a C program (faster),
diff --git a/configure.ac b/configure.ac
index eff6eb89..4f311a7b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2260,6 +2260,16 @@ if test "x$enable_rdmasniff" != "xno"; then
        AC_SUBST(RDMA_SRC)
 fi
 
+AC_ARG_ENABLE([sll-v2],
+[AC_HELP_STRING([--enable-sll-v2],[enable new LINKTYPE_LINUX_SLL2 capture support on Linux instead of legacy 
LINKTYPE_LINUX_SLL @<:@default=yes@:>@])],
+    [],
+    [enable_sll_v2=yes])
+
+if test "x$enable_sll_v2" != "xno" ; then
+       AC_DEFINE(PCAP_SUPPORT_SLL_V2, 1, [enable new LINKTYPE_LINUX_SLL2 capture support on Linux instead of legacy 
LINKTYPE_LINUX_SLL])
+       AC_SUBST(PCAP_SUPPORT_SLL_V2)
+fi
+
 AC_PROG_INSTALL
 
 AC_CONFIG_HEADER(config.h)
diff --git a/gencode.c b/gencode.c
index 959a56e6..cc4a64cf 100644
--- a/gencode.c
+++ b/gencode.c
@@ -1331,6 +1331,7 @@ init_linktype(compiler_state_t *cstate, pcap_t *p)
                break;
 
        case DLT_LINUX_SLL:     /* fake header for Linux cooked socket */
+       case DLT_LINUX_SLL2:
                cstate->off_linktype.constant_part = 14;
                cstate->off_linkpl.constant_part = 16;
                cstate->off_nl = 0;
@@ -3136,6 +3137,7 @@ gen_linktype(compiler_state_t *cstate, int proto)
                break;
 
        case DLT_LINUX_SLL:
+       case DLT_LINUX_SLL2:
                return gen_linux_sll_linktype(cstate, proto);
                /*NOTREACHED*/
                break;
@@ -7725,6 +7727,7 @@ gen_inbound(compiler_state_t *cstate, int dir)
                break;
 
        case DLT_LINUX_SLL:
+       case DLT_LINUX_SLL2:
                /* match outgoing packets */
                b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_H, LINUX_SLL_OUTGOING);
                if (!dir) {
diff --git a/pcap-common.c b/pcap-common.c
index ca809996..c2149eb4 100644
--- a/pcap-common.c
+++ b/pcap-common.c
@@ -1525,6 +1525,7 @@ swap_pseudo_headers(int linktype, struct pcap_pkthdr *hdr, u_char *data)
        switch (linktype) {
 
        case DLT_LINUX_SLL:
+       case DLT_LINUX_SLL2:
                swap_linux_sll_header(hdr, data);
                break;
 
diff --git a/pcap-linux.c b/pcap-linux.c
index 49144b64..4123c72b 100644
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -1910,6 +1910,9 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
 
                hdrp = (struct sll_header *)bp;
                hdrp->sll_pkttype = map_packet_type_to_sll_type(from.sll_pkttype);
+#ifdef PCAP_SUPPORT_SLL_V2
+               hdrp->sll_ifindex = htons(from.sll_ifindex);
+#endif
                hdrp->sll_hatype = htons(from.sll_hatype);
                hdrp->sll_halen = htons(from.sll_halen);
                memcpy(hdrp->sll_addr, from.sll_addr,
@@ -3689,6 +3692,7 @@ activate_new(pcap_t *handle)
                map_arphrd_to_dlt(handle, sock_fd, arptype, device, 1);
                if (handle->linktype == -1 ||
                    handle->linktype == DLT_LINUX_SLL ||
+                   handle->linktype == DLT_LINUX_SLL2 ||
                    handle->linktype == DLT_LINUX_IRDA ||
                    handle->linktype == DLT_LINUX_LAPD ||
                    handle->linktype == DLT_NETLINK ||
@@ -3796,7 +3800,11 @@ activate_new(pcap_t *handle)
                 * It uses cooked mode.
                 */
                handlep->cooked = 1;
+#ifdef PCAP_SUPPORT_SLL_V2
+               handle->linktype = DLT_LINUX_SLL2;
+#else
                handle->linktype = DLT_LINUX_SLL;
+#endif
 
                /*
                 * We're not bound to a device.
@@ -3892,6 +3900,7 @@ activate_new(pcap_t *handle)
                break;
 
        case DLT_LINUX_SLL:
+       case DLT_LINUX_SLL2:
                /*
                 * The type field is in the last 2 bytes of the
                 * DLT_LINUX_SLL header.
@@ -4964,6 +4973,9 @@ static int pcap_handle_packet_mmap(
                hdrp = (struct sll_header *)bp;
                hdrp->sll_pkttype = map_packet_type_to_sll_type(
                                                sll->sll_pkttype);
+#ifdef PCAP_SUPPORT_SLL_V2
+               hdrp->sll_ifindex = sll->sll_ifindex;
+#endif
                hdrp->sll_hatype = htons(sll->sll_hatype);
                hdrp->sll_halen = htons(sll->sll_halen);
                memcpy(hdrp->sll_addr, sll->sll_addr, SLL_ADDRLEN);
diff --git a/pcap.c b/pcap.c
index 3337bcb3..ecdd5aab 100644
--- a/pcap.c
+++ b/pcap.c
@@ -2841,7 +2841,11 @@ static struct dlt_choice dlt_choices[] = {
        DLT_CHOICE(FRELAY, "Frame Relay"),
        DLT_CHOICE(LOOP, "OpenBSD loopback"),
        DLT_CHOICE(ENC, "OpenBSD encapsulated IP"),
+#ifdef PCAP_SUPPORT_SLL_V2
+       DLT_CHOICE(LINUX_SLL2, "Linux cooked v2"),
+#else
        DLT_CHOICE(LINUX_SLL, "Linux cooked"),
+#endif
        DLT_CHOICE(LTALK, "Localtalk"),
        DLT_CHOICE(PFLOG, "OpenBSD pflog file"),
        DLT_CHOICE(PFSYNC, "Packet filter state syncing"),
diff --git a/pcap/sll.h b/pcap/sll.h
index c4d08862..82f009b2 100644
--- a/pcap/sll.h
+++ b/pcap/sll.h
@@ -75,19 +75,36 @@
 #define lib_pcap_sll_h
 
 /*
- * A DLT_LINUX_SLL fake link-layer header.
+ * DLT_LINUX_SLL and DLT_LINUX_SLL2 fake link-layer header.
+ * Uses PCAP_SUPPORT_SLL_V2 from config.h.
  */
-#define SLL_HDR_LEN    16              /* total header length */
+/* total header length */
+#ifdef PCAP_SUPPORT_SLL_V2
+#define SLL_HDR_LEN    24
+#else
+#define SLL_HDR_LEN    16
+#endif
+
 #define SLL_ADDRLEN    8               /* length of address field */
 
 #include <pcap/pcap-inttypes.h>
 
 struct sll_header {
+#ifdef PCAP_SUPPORT_SLL_V2
+       uint16_t sll_protocol;          /* protocol */
+       uint16_t reserved;              /* reserved */
+       int32_t sll_ifindex;            /* interface index, DLT_LINUX_SLL2 ONLY! */
+       uint16_t sll_hatype;            /* link-layer address type */
+       uint16_t sll_pkttype;           /* packet type */
+       uint16_t sll_halen;             /* link-layer address length */
+       uint8_t sll_addr[SLL_ADDRLEN];  /* link-layer address */
+#else
        uint16_t sll_pkttype;           /* packet type */
        uint16_t sll_hatype;            /* link-layer address type */
        uint16_t sll_halen;             /* link-layer address length */
        uint8_t sll_addr[SLL_ADDRLEN];  /* link-layer address */
        uint16_t sll_protocol;          /* protocol */
+#endif
 };
 
 /*
-- 
2.18.0

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