531 lines
14 KiB
C
531 lines
14 KiB
C
![]() |
/*
|
||
|
* 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.
|
||
|
*
|
||
|
* Author: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
|
||
|
*
|
||
|
* Modifications:
|
||
|
* 2003 May - Jesper Peterson <support@endace.com>
|
||
|
* Code shuffled around to suit fad-xxx.c structure
|
||
|
* Added atexit() handler to stop DAG if application is too lazy
|
||
|
*/
|
||
|
|
||
|
#ifndef lint
|
||
|
static const char rcsid[] =
|
||
|
"@(#) $Header: /tcpdump/master/libpcap/pcap-dag.c,v 1.1 2003-07-23 05:29:21 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 <sys/mman.h>
|
||
|
#include <sys/socket.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>
|
||
|
|
||
|
#define MAX_DAG_SNAPLEN 2040
|
||
|
|
||
|
typedef struct pcap_dag_node {
|
||
|
struct pcap_dag_node *next;
|
||
|
pcap_t *p;
|
||
|
} pcap_dag_node_t;
|
||
|
|
||
|
static pcap_dag_node_t *pcap_dags = NULL;
|
||
|
static int atexit_handler_installed = 0;
|
||
|
|
||
|
#ifdef DAG_ONLY
|
||
|
/* This code is reguired when compiling for a DAG device only. */
|
||
|
#include "pcap-dag.h"
|
||
|
|
||
|
/* Replace dag function names with pcap equivalent. */
|
||
|
#define dag_stats pcap_stats
|
||
|
#define dag_read pcap_read
|
||
|
#define dag_open_live pcap_open_live
|
||
|
#define dag_platform_finddevs pcap_platform_finddevs
|
||
|
#define dag_setfilter pcap_setfilter
|
||
|
#define dag_set_datalink_platform pcap_set_datalink_platform
|
||
|
#define dag_platform_close pcap_platform_close
|
||
|
#endif /* DAG_ONLY */
|
||
|
|
||
|
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 and frees dynamic memory held
|
||
|
* in the pcap_t structure.
|
||
|
*/
|
||
|
|
||
|
void dag_platform_close(pcap_t *p) {
|
||
|
|
||
|
#ifdef linux
|
||
|
if (p != NULL && p->md.is_dag && p->md.device != NULL) {
|
||
|
if(dag_stop(p->fd) < 0)
|
||
|
fprintf(stderr,"dag_stop %s: %s\n", p->md.device, strerror(errno));
|
||
|
if(dag_close(p->fd) < 0)
|
||
|
fprintf(stderr,"dag_close %s: %s\n", p->md.device, strerror(errno));
|
||
|
|
||
|
free(p->md.device);
|
||
|
}
|
||
|
#else
|
||
|
if (p != NULL && p->md.is_dag) {
|
||
|
if(dag_stop(p->fd) < 0)
|
||
|
fprintf(stderr,"dag_stop: %s\n", strerror(errno));
|
||
|
if(dag_close(p->fd) < 0)
|
||
|
fprintf(stderr,"dag_close: %s\n", strerror(errno));
|
||
|
}
|
||
|
#endif
|
||
|
delete_pcap_dag(p);
|
||
|
}
|
||
|
|
||
|
static void atexit_handler(void) {
|
||
|
while (pcap_dags != NULL) {
|
||
|
dag_platform_close(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;
|
||
|
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Get pointer to the ERF header for the next packet in the input
|
||
|
* stream. This function blocks until a packet becomes available.
|
||
|
*/
|
||
|
static dag_record_t *get_next_dag_header(pcap_t *p) {
|
||
|
register dag_record_t *record;
|
||
|
int rlen;
|
||
|
|
||
|
if (p->md.dag_mem_top - p->md.dag_mem_bottom < dag_record_size) {
|
||
|
p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), 0);
|
||
|
}
|
||
|
|
||
|
record = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom);
|
||
|
rlen = ntohs(record->rlen);
|
||
|
while (p->md.dag_mem_top - p->md.dag_mem_bottom < rlen) {
|
||
|
p->md.dag_mem_top = dag_offset(p->fd, &(p->md.dag_mem_bottom), 0);
|
||
|
record = (dag_record_t *)(p->md.dag_mem_base + p->md.dag_mem_bottom);
|
||
|
rlen = ntohs(record->rlen);
|
||
|
}
|
||
|
|
||
|
p->md.dag_mem_bottom += rlen;
|
||
|
|
||
|
return record;
|
||
|
}
|
||
|
|
||
|
/* Size of payload in ATM packets */
|
||
|
#define ATM_CAPTURE_SIZE 48
|
||
|
|
||
|
/* Size of payload of Ethernet packet */
|
||
|
#define ETHERNET_LENGTH(h) min(ntohs((h)->wlen) - 4, ntohs((h)->rlen) - dag_record_size - 2 - (ntohs((h)->wlen) & 0x3))
|
||
|
|
||
|
/* Size of HDLC packet */
|
||
|
#define HDLC_LENGTH(h) min(ntohs((h)->wlen) - 4, ntohs((h)->rlen) - dag_record_size)
|
||
|
|
||
|
#ifndef min
|
||
|
#define min(a, b) ((a) > (b) ? (b) : (a))
|
||
|
#endif
|
||
|
|
||
|
/*
|
||
|
* Swap byte ordering of unsigned long long on a big endian
|
||
|
* machine.
|
||
|
*/
|
||
|
static unsigned long long swapll(unsigned long long ull) {
|
||
|
#if (BYTE_ORDER == BIG_ENDIAN)
|
||
|
return ((ull & 0xff00000000000000LL) >> 56) |
|
||
|
((ull & 0x00ff000000000000LL) >> 40) |
|
||
|
((ull & 0x0000ff0000000000LL) >> 24) |
|
||
|
((ull & 0x000000ff00000000LL) >> 8) |
|
||
|
((ull & 0x00000000ff000000LL) << 8) |
|
||
|
((ull & 0x0000000000ff0000LL) << 24) |
|
||
|
((ull & 0x000000000000ff00LL) << 40) |
|
||
|
((ull & 0x00000000000000ffLL) << 56) ;
|
||
|
#else
|
||
|
return ull;
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Read at most max_packets from the capture stream and call the callback
|
||
|
* for each of them. Returns the number of packets handled or -1 if an
|
||
|
* error occured. A blocking
|
||
|
*/
|
||
|
int dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) {
|
||
|
u_char *dp = NULL;
|
||
|
int packet_len = 0, caplen = 0;
|
||
|
struct pcap_pkthdr pcap_header;
|
||
|
|
||
|
dag_record_t *header;
|
||
|
register unsigned long long ts;
|
||
|
|
||
|
/* Receive a single packet from the kernel */
|
||
|
header = get_next_dag_header(p);
|
||
|
dp = ((u_char *)header) + dag_record_size;
|
||
|
|
||
|
switch(header->type) {
|
||
|
case TYPE_ATM:
|
||
|
packet_len = ATM_CAPTURE_SIZE;
|
||
|
caplen = ATM_CAPTURE_SIZE;
|
||
|
break;
|
||
|
case TYPE_ETH:
|
||
|
packet_len = ntohs(header->wlen);
|
||
|
caplen = ETHERNET_LENGTH(header);
|
||
|
dp += 2;
|
||
|
break;
|
||
|
case TYPE_HDLC_POS:
|
||
|
packet_len = ntohs(header->wlen);
|
||
|
caplen = HDLC_LENGTH(header);
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
if (caplen > p->snapshot)
|
||
|
caplen = p->snapshot;
|
||
|
|
||
|
/* Run the packet filter if not using kernel filter */
|
||
|
if (p->fcode.bf_insns) {
|
||
|
if (bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen) == 0) {
|
||
|
/* rejected by filter */
|
||
|
return 0;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* convert between timestamp formats */
|
||
|
ts = swapll(header->ts);
|
||
|
pcap_header.ts.tv_sec = ts >> 32;
|
||
|
ts = ((ts & 0xffffffffULL) * 1000 * 1000);
|
||
|
ts += (ts & 0x80000000ULL) << 1; /* 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 += 1;
|
||
|
}
|
||
|
|
||
|
/* 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);
|
||
|
|
||
|
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 also ignored as it is
|
||
|
* not supported in hardware.
|
||
|
*
|
||
|
* See also pcap(3).
|
||
|
*/
|
||
|
pcap_t *dag_open_live(const char *device, int snaplen, int promisc, int to_ms, char *ebuf) {
|
||
|
char conf[30]; /* dag configure string */
|
||
|
pcap_t *handle;
|
||
|
|
||
|
if (device == NULL) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "device is NULL: %s", pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
/* Allocate a handle for this session. */
|
||
|
|
||
|
handle = malloc(sizeof(*handle));
|
||
|
if (handle == NULL) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc %s: %s", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/* Initialize some components of the pcap structure. */
|
||
|
|
||
|
memset(handle, 0, sizeof(*handle));
|
||
|
|
||
|
if (strstr(device, "/dev") == NULL) {
|
||
|
char * newDev = (char *)malloc(strlen(device) + 6);
|
||
|
newDev[0] = '\0';
|
||
|
strcat(newDev, "/dev/");
|
||
|
strcat(newDev,device);
|
||
|
device = newDev;
|
||
|
}
|
||
|
|
||
|
/* setup device parameters */
|
||
|
if((handle->fd = dag_open((char *)device)) < 0) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_open %s: %s", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/* set the card snap length as specified by the specified snaplen parameter */
|
||
|
if (snaplen > MAX_DAG_SNAPLEN) {
|
||
|
snaplen = MAX_DAG_SNAPLEN;
|
||
|
}
|
||
|
snprintf(conf, 30, "varlen slen=%d", (snaplen % 4) ? (snaplen + 3) & ~3 : snaplen); /* snap len has to be a multiple of 4 */
|
||
|
fprintf(stderr, "Configuring DAG with '%s'.\n", conf);
|
||
|
if(dag_configure(handle->fd, conf) < 0) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_configure %s: %s\n", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
if((handle->md.dag_mem_base = dag_mmap(handle->fd)) == MAP_FAILED) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE,"dag_mmap %s: %s\n", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
if(dag_start(handle->fd) < 0) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_start %s: %s\n", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* 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;
|
||
|
handle->md.is_dag = 1;
|
||
|
|
||
|
handle->snapshot = snaplen;
|
||
|
/*handle->md.timeout = to_ms; */
|
||
|
|
||
|
#ifdef linux
|
||
|
if (device) {
|
||
|
handle->md.device = strdup(device);
|
||
|
}
|
||
|
|
||
|
if (handle->md.device == NULL) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "str_dup %s: %s\n", device, pcap_strerror(errno));
|
||
|
free(handle);
|
||
|
return NULL;
|
||
|
}
|
||
|
#endif
|
||
|
|
||
|
/* set link type */
|
||
|
|
||
|
/* Check the type through a dagapi call.
|
||
|
*/
|
||
|
switch(dag_linktype(handle->fd)) {
|
||
|
case TYPE_HDLC_POS:
|
||
|
handle->linktype = DLT_CHDLC;
|
||
|
fprintf(stderr, "Set DAG linktype to %d (DLT_CHDLC)\n", handle->linktype);
|
||
|
break;
|
||
|
case TYPE_ETH:
|
||
|
handle->linktype = DLT_EN10MB;
|
||
|
fprintf(stderr, "Set DAG linktype to %d (DLT_EN10MB)\n", handle->linktype);
|
||
|
break;
|
||
|
case TYPE_ATM:
|
||
|
handle->linktype = DLT_ATM_RFC1483;
|
||
|
fprintf(stderr, "Set DAG linktype to %d (DLT_ATM_RFC1483)\n", handle->linktype);
|
||
|
break;
|
||
|
case TYPE_LEGACY:
|
||
|
handle->linktype = DLT_NULL;
|
||
|
fprintf(stderr, "Set DAG linktype to %d (DLT_NULL)\n", handle->linktype);
|
||
|
break;
|
||
|
default:
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "dag_open_live %s: unknown linktype %d\n", device, dag_linktype(handle->fd));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
handle->bufsize = 0;/*handle->snapshot;*/
|
||
|
|
||
|
if (new_pcap_dag(handle) < 0) {
|
||
|
snprintf(ebuf, PCAP_ERRBUF_SIZE, "new_pcap_dag %s: %s\n", device, pcap_strerror(errno));
|
||
|
return NULL;
|
||
|
}
|
||
|
|
||
|
return handle;
|
||
|
}
|
||
|
|
||
|
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;
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Get from "/proc/dag" all interfaces listed there; if they're
|
||
|
* already in the list of interfaces we have, that won't add another
|
||
|
* instance, but if they're not, that'll add them.
|
||
|
*
|
||
|
* We don't bother getting any addresses for them.
|
||
|
*
|
||
|
* We also don't fail if we couldn't open "/proc/dag"; we just leave
|
||
|
* the list of interfaces as is.
|
||
|
*/
|
||
|
int
|
||
|
dag_platform_finddevs(pcap_if_t **devlistp, char *errbuf)
|
||
|
{
|
||
|
FILE *proc_dag_f;
|
||
|
char linebuf[512];
|
||
|
int linenum;
|
||
|
unsigned char *p;
|
||
|
char name[512]; /* XXX - pick a size */
|
||
|
char *q, *saveq;
|
||
|
struct ifreq ifrflags;
|
||
|
int ret = 0;
|
||
|
|
||
|
/* Quick exit if /proc/dag not readable */
|
||
|
proc_dag_f = fopen("/proc/dag", "r");
|
||
|
if (proc_dag_f == NULL)
|
||
|
{
|
||
|
int i, fd;
|
||
|
char dev[16] = "dagx";
|
||
|
|
||
|
for (i = '0'; ret == 0 && i <= '9'; i++) {
|
||
|
dev[3] = i;
|
||
|
if (pcap_add_if(devlistp, dev, 0, NULL, errbuf) == -1) {
|
||
|
/*
|
||
|
* Failure.
|
||
|
*/
|
||
|
ret = -1;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return (ret);
|
||
|
}
|
||
|
|
||
|
for (linenum = 1;
|
||
|
fgets(linebuf, sizeof linebuf, proc_dag_f) != NULL; linenum++) {
|
||
|
|
||
|
/*
|
||
|
* Skip the first two lines - they're headers.
|
||
|
*/
|
||
|
if (linenum <= 2)
|
||
|
continue;
|
||
|
|
||
|
p = &linebuf[0];
|
||
|
|
||
|
if (*p == '\0' || *p == '\n' || *p != 'D')
|
||
|
continue; /* not a Dag line */
|
||
|
|
||
|
/*
|
||
|
* Get the interface name.
|
||
|
*/
|
||
|
q = &name[0];
|
||
|
while (*p != '\0' && *p != ':') {
|
||
|
if (*p != ' ')
|
||
|
*q++ = tolower(*p++);
|
||
|
else
|
||
|
p++;
|
||
|
}
|
||
|
*q = '\0';
|
||
|
|
||
|
/*
|
||
|
* Add an entry for this interface, with no addresses.
|
||
|
*/
|
||
|
p[strlen(p) - 1] = '\0'; /* get rid of \n */
|
||
|
if (pcap_add_if(devlistp, name, 0, strdup(p + 2), errbuf) == -1) {
|
||
|
/*
|
||
|
* Failure.
|
||
|
*/
|
||
|
ret = -1;
|
||
|
break;
|
||
|
}
|
||
|
}
|
||
|
if (ret != -1) {
|
||
|
/*
|
||
|
* Well, we didn't fail for any other reason; did we
|
||
|
* fail due to an error reading the file?
|
||
|
*/
|
||
|
if (ferror(proc_dag_f)) {
|
||
|
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
|
||
|
"Error reading /proc/dag: %s",
|
||
|
pcap_strerror(errno));
|
||
|
ret = -1;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
(void)fclose(proc_dag_f);
|
||
|
return (ret);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Installs the gven 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.
|
||
|
*/
|
||
|
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) {
|
||
|
snprintf(p->errbuf, sizeof(p->errbuf),
|
||
|
"malloc: %s", pcap_strerror(errno));
|
||
|
return -1;
|
||
|
}
|
||
|
|
||
|
p->md.use_bpf = 0;
|
||
|
|
||
|
return (0);
|
||
|
}
|
||
|
|
||
|
int
|
||
|
dag_set_datalink_platform(pcap_t *p, int dlt)
|
||
|
{
|
||
|
return (0);
|
||
|
}
|