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pcap-dag.c
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pcap-dag.c
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/*
* pcap-dag.c: Packet capture interface for Endace DAG card.
*
* The functionality of this code attempts to mimic that of pcap-linux as much
* as possible. This code is compiled in several different ways depending on
* whether DAG_ONLY and HAVE_DAG_API are defined. If HAVE_DAG_API is not
* defined it should not get compiled in, otherwise if DAG_ONLY is defined then
* the 'dag_' function calls are renamed to 'pcap_' equivalents. If DAG_ONLY
* is not defined then nothing is altered - the dag_ functions will be
* called as required from their pcap-linux/bpf equivalents.
*
* Authors: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
* Modifications: Jesper Peterson <support@endace.com>
* Koryn Grant <support@endace.com>
* Stephen Donnelly <support@endace.com>
*/
#ifndef lint
static const char rcsid[] _U_ =
"@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.39 2008-04-14 20:40:58 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h> /* optionally get BSD define */
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "pcap-int.h"
#include <ctype.h>
#include <netinet/in.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
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 "pcap-dag.h"
/*
* DAG devices have names beginning with "dag", followed by a number
* from 0 to MAXDAG.
*/
#define MAXDAG 31
#define ATM_CELL_SIZE 52
#define ATM_HDR_SIZE 4
/*
* A header containing additional MTP information.
*/
#define MTP2_SENT_OFFSET 0 /* 1 byte */
#define MTP2_ANNEX_A_USED_OFFSET 1 /* 1 byte */
#define MTP2_LINK_NUMBER_OFFSET 2 /* 2 bytes */
#define MTP2_HDR_LEN 4 /* length of the header */
#define MTP2_ANNEX_A_NOT_USED 0
#define MTP2_ANNEX_A_USED 1
#define MTP2_ANNEX_A_USED_UNKNOWN 2
/* SunATM pseudo header */
struct sunatm_hdr {
unsigned char flags; /* destination and traffic type */
unsigned char vpi; /* VPI */
unsigned short vci; /* VCI */
};
typedef struct pcap_dag_node {
struct pcap_dag_node *next;
pcap_t *p;
pid_t pid;
} pcap_dag_node_t;
static pcap_dag_node_t *pcap_dags = NULL;
static int atexit_handler_installed = 0;
static const unsigned short endian_test_word = 0x0100;
#define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word))
#define MAX_DAG_PACKET 65536
static unsigned char TempPkt[MAX_DAG_PACKET];
static int dag_setfilter(pcap_t *p, struct bpf_program *fp);
static int dag_stats(pcap_t *p, struct pcap_stat *ps);
static int dag_set_datalink(pcap_t *p, int dlt);
static int dag_get_datalink(pcap_t *p);
static int dag_setnonblock(pcap_t *p, int nonblock, char *errbuf);
static void
delete_pcap_dag(pcap_t *p)
{
pcap_dag_node_t *curr = NULL, *prev = NULL;
for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
/* empty */
}
if (curr != NULL && curr->p == p) {
if (prev != NULL) {
prev->next = curr->next;
} else {
pcap_dags = curr->next;
}
}
}
/*
* Performs a graceful shutdown of the DAG card, frees dynamic memory held
* in the pcap_t structure, and closes the file descriptor for the DAG card.
*/
static void
dag_platform_cleanup(pcap_t *p)
{
if (p != NULL) {
#ifdef HAVE_DAG_STREAMS_API
if(dag_stop_stream(p->fd, p->md.dag_stream) < 0)
fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
if(dag_detach_stream(p->fd, p->md.dag_stream) < 0)
fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
#else
if(dag_stop(p->fd) < 0)
fprintf(stderr,"dag_stop: %s\n", strerror(errno));
#endif /* HAVE_DAG_STREAMS_API */
if(p->fd != -1) {
if(dag_close(p->fd) < 0)
fprintf(stderr,"dag_close: %s\n", strerror(errno));
p->fd = -1;
}
delete_pcap_dag(p);
pcap_cleanup_live_common(p);
}
/* Note: don't need to call close(p->fd) here as dag_close(p->fd) does this. */
}
static void
atexit_handler(void)
{
while (pcap_dags != NULL) {
if (pcap_dags->pid == getpid()) {
dag_platform_cleanup(pcap_dags->p);
} else {
delete_pcap_dag(pcap_dags->p);
}
}
}
static int
new_pcap_dag(pcap_t *p)
{
pcap_dag_node_t *node = NULL;
if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
return -1;
}
if (!atexit_handler_installed) {
atexit(atexit_handler);
atexit_handler_installed = 1;
}
node->next = pcap_dags;
node->p = p;
node->pid = getpid();
pcap_dags = node;
return 0;
}
static unsigned int
dag_erf_ext_header_count(uint8_t * erf, size_t len)
{
uint32_t hdr_num = 0;
uint8_t hdr_type;
/* basic sanity checks */
if ( erf == NULL )
return 0;
if ( len < 16 )
return 0;
/* check if we have any extension headers */
if ( (erf[8] & 0x80) == 0x00 )
return 0;
/* loop over the extension headers */
do {
/* sanity check we have enough bytes */
if ( len <= (24 + (hdr_num * 8)) )
return hdr_num;
/* get the header type */
hdr_type = erf[(16 + (hdr_num * 8))];
hdr_num++;
} while ( hdr_type & 0x80 );
return hdr_num;
}
/*
* Read at most max_packets from the capture stream and call the callback
* for each of them. Returns the number of packets handled, -1 if an
* error occured, or -2 if we were told to break out of the loop.
*/
static int
dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
unsigned int processed = 0;
int flags = p->md.dag_offset_flags;
unsigned int nonblocking = flags & DAGF_NONBLOCK;
unsigned int num_ext_hdr = 0;
/* Get the next bufferful of packets (if necessary). */
while (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) {
/*
* Has "pcap_breakloop()" been called?
*/
if (p->break_loop) {
/*
* Yes - clear the flag that indicates that
* it has, and return -2 to indicate that
* we were told to break out of the loop.
*/
p->break_loop = 0;
return -2;
}
#ifdef HAVE_DAG_STREAMS_API
/* dag_advance_stream() will block (unless nonblock is called)
* until 64kB of data has accumulated.
* If to_ms is set, it will timeout before 64kB has accumulated.
* We wait for 64kB because processing a few packets at a time
* can cause problems at high packet rates (>200kpps) due
* to inefficiencies.
* This does mean if to_ms is not specified the capture may 'hang'
* for long periods if the data rate is extremely slow (<64kB/sec)
* If non-block is specified it will return immediately. The user
* is then responsible for efficiency.
*/
if ( NULL == (p->md.dag_mem_top = dag_advance_stream(p->fd, p->md.dag_stream, &(p->md.dag_mem_bottom))) ) {
return -1;
}
#else
/* dag_offset does not support timeouts */
p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), flags);
#endif /* HAVE_DAG_STREAMS_API */
if (nonblocking && (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size))
{
/* Pcap is configured to process only available packets, and there aren't any, return immediately. */
return 0;
}
if(!nonblocking &&
p->md.dag_timeout &&
(p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size))
{
/* Blocking mode, but timeout set and no data has arrived, return anyway.*/
return 0;
}
}
/* Process the packets. */
while (p->md.dag_mem_top - p->md.dag_mem_bottom >= dag_record_size) {
unsigned short packet_len = 0;
int caplen = 0;
struct pcap_pkthdr pcap_header;
#ifdef HAVE_DAG_STREAMS_API
dag_record_t *header = (dag_record_t *)(p->md.dag_mem_bottom);
#else
dag_record_t *header = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom);
#endif /* HAVE_DAG_STREAMS_API */
u_char *dp = ((u_char *)header); /* + dag_record_size; */
unsigned short rlen;
/*
* Has "pcap_breakloop()" been called?
*/
if (p->break_loop) {
/*
* Yes - clear the flag that indicates that
* it has, and return -2 to indicate that
* we were told to break out of the loop.
*/
p->break_loop = 0;
return -2;
}
rlen = ntohs(header->rlen);
if (rlen < dag_record_size)
{
strncpy(p->errbuf, "dag_read: record too small", PCAP_ERRBUF_SIZE);
return -1;
}
p->md.dag_mem_bottom += rlen;
/* Count lost packets. */
switch((header->type & 0x7f)) {
/* in these types the color value overwrites the lctr */
case TYPE_COLOR_HDLC_POS:
case TYPE_COLOR_ETH:
case TYPE_DSM_COLOR_HDLC_POS:
case TYPE_DSM_COLOR_ETH:
case TYPE_COLOR_MC_HDLC_POS:
case TYPE_COLOR_HASH_ETH:
case TYPE_COLOR_HASH_POS:
break;
default:
if (header->lctr) {
if (p->md.stat.ps_drop > (UINT_MAX - ntohs(header->lctr))) {
p->md.stat.ps_drop = UINT_MAX;
} else {
p->md.stat.ps_drop += ntohs(header->lctr);
}
}
}
if ((header->type & 0x7f) == TYPE_PAD) {
continue;
}
num_ext_hdr = dag_erf_ext_header_count(dp, rlen);
/* ERF encapsulation */
/* The Extensible Record Format is not dropped for this kind of encapsulation,
* and will be handled as a pseudo header by the decoding application.
* The information carried in the ERF header and in the optional subheader (if present)
* could be merged with the libpcap information, to offer a better decoding.
* The packet length is
* o the length of the packet on the link (header->wlen),
* o plus the length of the ERF header (dag_record_size), as the length of the
* pseudo header will be adjusted during the decoding,
* o plus the length of the optional subheader (if present).
*
* The capture length is header.rlen and the byte stuffing for alignment will be dropped
* if the capture length is greater than the packet length.
*/
if (p->linktype == DLT_ERF) {
packet_len = ntohs(header->wlen) + dag_record_size;
caplen = rlen;
switch ((header->type & 0x7f)) {
case TYPE_MC_AAL5:
case TYPE_MC_ATM:
case TYPE_MC_HDLC:
case TYPE_MC_RAW_CHANNEL:
case TYPE_MC_RAW:
case TYPE_MC_AAL2:
case TYPE_COLOR_MC_HDLC_POS:
packet_len += 4; /* MC header */
break;
case TYPE_COLOR_HASH_ETH:
case TYPE_DSM_COLOR_ETH:
case TYPE_COLOR_ETH:
case TYPE_ETH:
packet_len += 2; /* ETH header */
break;
} /* switch type */
/* Include ERF extension headers */
packet_len += (8 * num_ext_hdr);
if (caplen > packet_len) {
caplen = packet_len;
}
} else {
/* Other kind of encapsulation according to the header Type */
/* Skip over generic ERF header */
dp += dag_record_size;
/* Skip over extension headers */
dp += 8 * num_ext_hdr;
switch((header->type & 0x7f)) {
case TYPE_ATM:
case TYPE_AAL5:
if (header->type == TYPE_AAL5) {
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size;
}
case TYPE_MC_ATM:
if (header->type == TYPE_MC_ATM) {
caplen = packet_len = ATM_CELL_SIZE;
dp+=4;
}
case TYPE_MC_AAL5:
if (header->type == TYPE_MC_AAL5) {
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size - 4;
dp+=4;
}
if (header->type == TYPE_ATM) {
caplen = packet_len = ATM_CELL_SIZE;
}
if (p->linktype == DLT_SUNATM) {
struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
unsigned long rawatm;
rawatm = ntohl(*((unsigned long *)dp));
sunatm->vci = htons((rawatm >> 4) & 0xffff);
sunatm->vpi = (rawatm >> 20) & 0x00ff;
sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
((dp[ATM_HDR_SIZE] == 0xaa &&
dp[ATM_HDR_SIZE+1] == 0xaa &&
dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));
} else {
packet_len -= ATM_HDR_SIZE;
caplen -= ATM_HDR_SIZE;
dp += ATM_HDR_SIZE;
}
break;
case TYPE_COLOR_HASH_ETH:
case TYPE_DSM_COLOR_ETH:
case TYPE_COLOR_ETH:
case TYPE_ETH:
packet_len = ntohs(header->wlen);
packet_len -= (p->md.dag_fcs_bits >> 3);
caplen = rlen - dag_record_size - 2;
if (caplen > packet_len) {
caplen = packet_len;
}
dp += 2;
break;
case TYPE_COLOR_HASH_POS:
case TYPE_DSM_COLOR_HDLC_POS:
case TYPE_COLOR_HDLC_POS:
case TYPE_HDLC_POS:
packet_len = ntohs(header->wlen);
packet_len -= (p->md.dag_fcs_bits >> 3);
caplen = rlen - dag_record_size;
if (caplen > packet_len) {
caplen = packet_len;
}
break;
case TYPE_COLOR_MC_HDLC_POS:
case TYPE_MC_HDLC:
packet_len = ntohs(header->wlen);
packet_len -= (p->md.dag_fcs_bits >> 3);
caplen = rlen - dag_record_size - 4;
if (caplen > packet_len) {
caplen = packet_len;
}
/* jump the MC_HDLC_HEADER */
dp += 4;
#ifdef DLT_MTP2_WITH_PHDR
if (p->linktype == DLT_MTP2_WITH_PHDR) {
/* Add the MTP2 Pseudo Header */
caplen += MTP2_HDR_LEN;
packet_len += MTP2_HDR_LEN;
TempPkt[MTP2_SENT_OFFSET] = 0;
TempPkt[MTP2_ANNEX_A_USED_OFFSET] = MTP2_ANNEX_A_USED_UNKNOWN;
*(TempPkt+MTP2_LINK_NUMBER_OFFSET) = ((header->rec.mc_hdlc.mc_header>>16)&0x01);
*(TempPkt+MTP2_LINK_NUMBER_OFFSET+1) = ((header->rec.mc_hdlc.mc_header>>24)&0xff);
memcpy(TempPkt+MTP2_HDR_LEN, dp, caplen);
dp = TempPkt;
}
#endif
break;
case TYPE_IPV4:
case TYPE_IPV6:
packet_len = ntohs(header->wlen);
caplen = rlen - dag_record_size;
if (caplen > packet_len) {
caplen = packet_len;
}
break;
/* These types have no matching 'native' DLT, but can be used with DLT_ERF above */
case TYPE_MC_RAW:
case TYPE_MC_RAW_CHANNEL:
case TYPE_IP_COUNTER:
case TYPE_TCP_FLOW_COUNTER:
case TYPE_INFINIBAND:
case TYPE_RAW_LINK:
case TYPE_INFINIBAND_LINK:
default:
/* Unhandled ERF type.
* Ignore rather than generating error
*/
continue;
} /* switch type */
/* Skip over extension headers */
caplen -= (8 * num_ext_hdr);
} /* ERF encapsulation */
if (caplen > p->snapshot)
caplen = p->snapshot;
/* Run the packet filter if there is one. */
if ((p->fcode.bf_insns == NULL) || bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {
/* convert between timestamp formats */
register unsigned long long ts;
if (IS_BIGENDIAN()) {
ts = SWAPLL(header->ts);
} else {
ts = header->ts;
}
pcap_header.ts.tv_sec = ts >> 32;
ts = (ts & 0xffffffffULL) * 1000000;
ts += 0x80000000; /* rounding */
pcap_header.ts.tv_usec = ts >> 32;
if (pcap_header.ts.tv_usec >= 1000000) {
pcap_header.ts.tv_usec -= 1000000;
pcap_header.ts.tv_sec++;
}
/* Fill in our own header data */
pcap_header.caplen = caplen;
pcap_header.len = packet_len;
/* Count the packet. */
p->md.stat.ps_recv++;
/* Call the user supplied callback function */
callback(user, &pcap_header, dp);
/* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
processed++;
if (processed == cnt && cnt > 0)
{
/* Reached the user-specified limit. */
return cnt;
}
}
}
return processed;
}
static int
dag_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
{
strlcpy(p->errbuf, "Sending packets isn't supported on DAG cards",
PCAP_ERRBUF_SIZE);
return (-1);
}
/*
* Get a handle for a live capture from the given DAG device. Passing a NULL
* device will result in a failure. The promisc flag is ignored because DAG
* cards are always promiscuous. The to_ms parameter is used in setting the
* API polling parameters.
*
* snaplen is now also ignored, until we get per-stream slen support. Set
* slen with approprite DAG tool BEFORE pcap_activate().
*
* See also pcap(3).
*/
static int dag_activate(pcap_t* handle)
{
#if 0
char conf[30]; /* dag configure string */
#endif
char *s;
int n;
daginf_t* daginf;
char * newDev = NULL;
char * device = handle->opt.source;
#ifdef HAVE_DAG_STREAMS_API
uint32_t mindata;
struct timeval maxwait;
struct timeval poll;
#endif
if (device == NULL) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno));
return -1;
}
/* Initialize some components of the pcap structure. */
#ifdef HAVE_DAG_STREAMS_API
newDev = (char *)malloc(strlen(device) + 16);
if (newDev == NULL) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate string for device name: %s\n", pcap_strerror(errno));
goto fail;
}
/* Parse input name to get dag device and stream number if provided */
if (dag_parse_name(device, newDev, strlen(device) + 16, &handle->md.dag_stream) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_parse_name: %s\n", pcap_strerror(errno));
goto fail;
}
device = newDev;
if (handle->md.dag_stream%2) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_parse_name: tx (even numbered) streams not supported for capture\n");
goto fail;
}
#else
if (strncmp(device, "/dev/", 5) != 0) {
newDev = (char *)malloc(strlen(device) + 5);
if (newDev == NULL) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't allocate string for device name: %s\n", pcap_strerror(errno));
goto fail;
}
strcpy(newDev, "/dev/");
strcat(newDev, device);
device = newDev;
}
#endif /* HAVE_DAG_STREAMS_API */
/* setup device parameters */
if((handle->fd = dag_open((char *)device)) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_open %s: %s", device, pcap_strerror(errno));
goto fail;
}
#ifdef HAVE_DAG_STREAMS_API
/* Open requested stream. Can fail if already locked or on error */
if (dag_attach_stream(handle->fd, handle->md.dag_stream, 0, 0) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_attach_stream: %s\n", pcap_strerror(errno));
goto failclose;
}
/* Set up default poll parameters for stream
* Can be overridden by pcap_set_nonblock()
*/
if (dag_get_stream_poll(handle->fd, handle->md.dag_stream,
&mindata, &maxwait, &poll) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_get_stream_poll: %s\n", pcap_strerror(errno));
goto faildetach;
}
/* Amount of data to collect in Bytes before calling callbacks.
* Important for efficiency, but can introduce latency
* at low packet rates if to_ms not set!
*/
mindata = 65536;
/* Obey md.timeout (was to_ms) if supplied. This is a good idea!
* Recommend 10-100ms. Calls will time out even if no data arrived.
*/
maxwait.tv_sec = handle->md.timeout/1000;
maxwait.tv_usec = (handle->md.timeout%1000) * 1000;
if (dag_set_stream_poll(handle->fd, handle->md.dag_stream,
mindata, &maxwait, &poll) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_set_stream_poll: %s\n", pcap_strerror(errno));
goto faildetach;
}
#else
if((handle->md.dag_mem_base = dag_mmap(handle->fd)) == MAP_FAILED) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,"dag_mmap %s: %s\n", device, pcap_strerror(errno));
goto failclose;
}
#endif /* HAVE_DAG_STREAMS_API */
/* XXX Not calling dag_configure() to set slen; this is unsafe in
* multi-stream environments as the gpp config is global.
* Once the firmware provides 'per-stream slen' this can be supported
* again via the Config API without side-effects */
#if 0
/* set the card snap length to the specified snaplen parameter */
/* This is a really bad idea, as different cards have different
* valid slen ranges. Should fix in Config API. */
if (handle->snapshot == 0 || handle->snapshot > MAX_DAG_SNAPLEN) {
handle->snapshot = MAX_DAG_SNAPLEN;
} else if (snaplen < MIN_DAG_SNAPLEN) {
handle->snapshot = MIN_DAG_SNAPLEN;
}
/* snap len has to be a multiple of 4 */
snprintf(conf, 30, "varlen slen=%d", (snaplen + 3) & ~3);
if(dag_configure(handle->fd, conf) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,"dag_configure %s: %s\n", device, pcap_strerror(errno));
goto faildetach;
}
#endif
#ifdef HAVE_DAG_STREAMS_API
if(dag_start_stream(handle->fd, handle->md.dag_stream) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_start_stream %s: %s\n", device, pcap_strerror(errno));
goto faildetach;
}
#else
if(dag_start(handle->fd) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dag_start %s: %s\n", device, pcap_strerror(errno));
goto failclose;
}
#endif /* HAVE_DAG_STREAMS_API */
/*
* Important! You have to ensure bottom is properly
* initialized to zero on startup, it won't give you
* a compiler warning if you make this mistake!
*/
handle->md.dag_mem_bottom = 0;
handle->md.dag_mem_top = 0;
/*
* Find out how many FCS bits we should strip.
* First, query the card to see if it strips the FCS.
*/
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;
/* Note that no FCS will be supplied. */
handle->linktype_ext = LT_FCS_DATALINK_EXT(0);
} else {
/*
* Start out assuming it's 32 bits.
*/
handle->md.dag_fcs_bits = 32;
/* 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;
} else {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
"pcap_activate %s: bad ERF_FCS_BITS value (%d) in environment\n", device, n);
goto failstop;
}
}
/*
* Did the user request that they not be stripped?
*/
if ((s = getenv("ERF_DONT_STRIP_FCS")) != NULL) {
/* Yes. Note the number of bytes that will be
supplied. */
handle->linktype_ext = LT_FCS_DATALINK_EXT(handle->md.dag_fcs_bits/16);
/* And don't strip them. */
handle->md.dag_fcs_bits = 0;
}
}
handle->md.dag_timeout = handle->md.timeout;
handle->linktype = -1;
if (dag_get_datalink(handle) < 0)
goto failstop;
handle->bufsize = 0;
if (new_pcap_dag(handle) < 0) {
snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "new_pcap_dag %s: %s\n", device, pcap_strerror(errno));
goto failstop;
}
/*
* "select()" and "poll()" don't work on DAG device descriptors.
*/
handle->selectable_fd = -1;
if (newDev != NULL) {
free((char *)newDev);
}
handle->read_op = dag_read;
handle->inject_op = dag_inject;
handle->setfilter_op = dag_setfilter;
handle->setdirection_op = NULL; /* Not implemented.*/
handle->set_datalink_op = dag_set_datalink;
handle->getnonblock_op = pcap_getnonblock_fd;
handle->setnonblock_op = dag_setnonblock;
handle->stats_op = dag_stats;
handle->cleanup_op = dag_platform_cleanup;
handle->md.stat.ps_drop = 0;
handle->md.stat.ps_recv = 0;
handle->md.stat.ps_ifdrop = 0;
return 0;
#ifdef HAVE_DAG_STREAMS_API
failstop:
if (dag_stop_stream(handle->fd, handle->md.dag_stream) < 0) {
fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
}
faildetach:
if (dag_detach_stream(handle->fd, handle->md.dag_stream) < 0)
fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));
#else
failstop:
if (dag_stop(handle->fd) < 0)
fprintf(stderr,"dag_stop: %s\n", strerror(errno));
#endif /* HAVE_DAG_STREAMS_API */
failclose:
if (dag_close(handle->fd) < 0)
fprintf(stderr,"dag_close: %s\n", strerror(errno));
delete_pcap_dag(handle);
fail:
pcap_cleanup_live_common(handle);
if (newDev != NULL) {
free((char *)newDev);
}
return PCAP_ERROR;
}
pcap_t *dag_create(const char *device, char *ebuf, int *is_ours)
{
const char *cp;
char *cpend;
long devnum;
pcap_t *p;
/* Does this look like a DAG device? */
cp = strrchr(device, '/');
if (cp == NULL)
cp = device;
/* Does it begin with "dag"? */
if (strncmp(cp, "dag", 3) != 0) {
/* Nope, doesn't begin with "dag" */
*is_ours = 0;
return NULL;
}
/* Yes - is "dag" followed by a number from 0 to MAXDAG? */
cp += 3;
devnum = strtol(cp, &cpend, 10);
if (cpend == cp || *cpend != '\0') {
/* Not followed by a number. */
*is_ours = 0;
return NULL;
}
if (devnum < 0 || devnum > MAXDAG) {
/* Followed by a non-valid number. */
*is_ours = 0;
return NULL;
}
/* OK, it's probably ours. */
*is_ours = 1;
p = pcap_create_common(device, ebuf);
if (p == NULL)
return NULL;
p->activate_op = dag_activate;
return p;
}
static int
dag_stats(pcap_t *p, struct pcap_stat *ps) {
/* This needs to be filled out correctly. Hopefully a dagapi call will
provide all necessary information.
*/
/*p->md.stat.ps_recv = 0;*/
/*p->md.stat.ps_drop = 0;*/
*ps = p->md.stat;
return 0;
}
/*
* Previously we just generated a list of all possible names and let
* pcap_add_if() attempt to open each one, but with streams this adds up
* to 81 possibilities which is inefficient.
*
* Since we know more about the devices we can prune the tree here.
* pcap_add_if() will still retest each device but the total number of
* open attempts will still be much less than the naive approach.
*/
int
dag_findalldevs(pcap_if_t **devlistp, char *errbuf)
{
char name[12]; /* XXX - pick a size */
int ret = 0;
int c;
char dagname[DAGNAME_BUFSIZE];
int dagstream;
int dagfd;
/* Try all the DAGs 0-MAXDAG */
for (c = 0; c <= MAXDAG; c++) {
snprintf(name, 12, "dag%d", c);
if (-1 == dag_parse_name(name, dagname, DAGNAME_BUFSIZE, &dagstream))
{
return -1;
}
if ( (dagfd = dag_open(dagname)) >= 0 ) {
if (pcap_add_if(devlistp, name, 0, NULL, errbuf) == -1) {
/*
* Failure.
*/
ret = -1;
}
#ifdef HAVE_DAG_STREAMS_API
{
int stream, rxstreams;
rxstreams = dag_rx_get_stream_count(dagfd);
for(stream=0;stream<DAG_STREAM_MAX;stream+=2) {
if (0 == dag_attach_stream(dagfd, stream, 0, 0)) {
dag_detach_stream(dagfd, stream);
snprintf(name, 10, "dag%d:%d", c, stream);
if (pcap_add_if(devlistp, name, 0, NULL, errbuf) == -1) {
/*
* Failure.
*/
ret = -1;
}
rxstreams--;
if(rxstreams <= 0) {
break;
}
}
}
}
#endif /* HAVE_DAG_STREAMS_API */
dag_close(dagfd);
}
}
return (ret);
}
/*
* Installs the given bpf filter program in the given pcap structure. There is
* no attempt to store the filter in kernel memory as that is not supported
* with DAG cards.
*/
static int
dag_setfilter(pcap_t *p, struct bpf_program *fp)
{
if (!p)
return -1;
if (!fp) {
strncpy(p->errbuf, "setfilter: No filter specified",
sizeof(p->errbuf));
return -1;
}
/* Make our private copy of the filter */
if (install_bpf_program(p, fp) < 0)
return -1;
p->md.use_bpf = 0;
return (0);
}
static int
dag_set_datalink(pcap_t *p, int dlt)
{
p->linktype = dlt;
return (0);
}
static int
dag_setnonblock(pcap_t *p, int nonblock, char *errbuf)
{
/*
* Set non-blocking mode on the FD.
* XXX - is that necessary? If not, don't bother calling it,
* and have a "dag_getnonblock()" function that looks at
* "p->md.dag_offset_flags".
*/
if (pcap_setnonblock_fd(p, nonblock, errbuf) < 0)
return (-1);
#ifdef HAVE_DAG_STREAMS_API
{