diff options
author | guy <guy> | 2005-01-21 10:11:39 +0000 |
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committer | guy <guy> | 2005-01-21 10:11:39 +0000 |
commit | 2dd3e0acd6d7e40d046113d562efea81b876f6fd (patch) | |
tree | b154ab039d8394a0616817c021380cd35958305b /pcap-dag.c | |
parent | 2f23c057fc71caaea4e57a151d23c0d0fc6c2552 (diff) | |
download | libpcap-2dd3e0acd6d7e40d046113d562efea81b876f6fd.tar.gz |
From Koryn Grant:
The DAG 4.2 OC-48 cards (and revisions thereof) produce ERF
records that do not contain the trailing FCS. However,
pcap-dag.c assumed that there is an FCS and strips the final
word of the packet. This meant that packets captured with
libpcap on a DAG 4.2 are truncated by four bytes, unless a
magical environment variable (ERF_FCS_BITS) was set. This patch
autodetects when the DAG card is a 4.2, and turns off the
FCS-stripping feature so that packets are no longer truncated.
Also, include "dagnew.h" and "dagapi.h" with quotes, not angle
brackets, as they should be in the user search path, not the
system search path.
Diffstat (limited to 'pcap-dag.c')
-rw-r--r-- | pcap-dag.c | 19 |
1 files changed, 14 insertions, 5 deletions
@@ -15,7 +15,7 @@ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.19 2004-11-10 09:28:25 guy Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.20 2005-01-21 10:11:39 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -41,8 +41,8 @@ struct mbuf; /* Squelch compiler warnings on some platforms for */ struct rtentry; /* declarations in <net/if.h> */ #include <net/if.h> -#include <dagnew.h> -#include <dagapi.h> +#include "dagnew.h" +#include "dagapi.h" #define MIN_DAG_SNAPLEN 12 #define MAX_DAG_SNAPLEN 2040 @@ -385,6 +385,7 @@ dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebu pcap_t *handle; char *s; int n; + daginf_t* daginf; if (device == NULL) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno)); @@ -454,9 +455,17 @@ dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebu */ handle->md.dag_mem_bottom = 0; handle->md.dag_mem_top = 0; - - /* TODO: query the card */ handle->md.dag_fcs_bits = 32; + + /* Query the card first for special cases. */ + daginf = dag_info(handle->fd); + if ((0x4200 == daginf->device_code) || (0x4230 == daginf->device_code)) + { + /* DAG 4.2S and 4.23S already strip the FCS. Stripping the final word again truncates the packet. */ + handle->md.dag_fcs_bits = 0; + } + + /* Then allow an environment variable to override. */ if ((s = getenv("ERF_FCS_BITS")) != NULL) { if ((n = atoi(s)) == 0 || n == 16|| n == 32) { handle->md.dag_fcs_bits = n; |