nexmon – Rev 1
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#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <netinet/in.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>
#include <snf.h>
#if SNF_VERSION_API >= 0x0003
#define SNF_HAVE_INJECT_API
#endif
#include "pcap-int.h"
#include "pcap-snf.h"
/*
* Private data for capturing on SNF devices.
*/
struct pcap_snf {
snf_handle_t snf_handle; /* opaque device handle */
snf_ring_t snf_ring; /* opaque device ring handle */
#ifdef SNF_HAVE_INJECT_API
snf_inject_t snf_inj; /* inject handle, if inject is used */
#endif
int snf_timeout;
int snf_boardnum;
};
static int
snf_set_datalink(pcap_t *p, int dlt)
{
p->linktype = dlt;
return (0);
}
static int
snf_pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
struct snf_ring_stats stats;
struct pcap_snf *snfps = p->priv;
int rc;
if ((rc = snf_ring_getstats(snfps->snf_ring, &stats))) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snf_get_stats: %s",
pcap_strerror(rc));
return -1;
}
ps->ps_recv = stats.ring_pkt_recv + stats.ring_pkt_overflow;
ps->ps_drop = stats.ring_pkt_overflow;
ps->ps_ifdrop = stats.nic_pkt_overflow + stats.nic_pkt_bad;
return 0;
}
static void
snf_platform_cleanup(pcap_t *p)
{
struct pcap_snf *ps = p->priv;
if (p == NULL)
return;
#ifdef SNF_HAVE_INJECT_API
if (ps->snf_inj)
snf_inject_close(ps->snf_inj);
#endif
snf_ring_close(ps->snf_ring);
snf_close(ps->snf_handle);
pcap_cleanup_live_common(p);
}
static int
snf_getnonblock(pcap_t *p, char *errbuf)
{
struct pcap_snf *ps = p->priv;
return (ps->snf_timeout == 0);
}
static int
snf_setnonblock(pcap_t *p, int nonblock, char *errbuf)
{
struct pcap_snf *ps = p->priv;
if (nonblock)
ps->snf_timeout = 0;
else {
if (p->opt.timeout <= 0)
ps->snf_timeout = -1; /* forever */
else
ps->snf_timeout = p->opt.timeout;
}
return (0);
}
#define _NSEC_PER_SEC 1000000000
static inline
struct timeval
snf_timestamp_to_timeval(const int64_t ts_nanosec, const int tstamp_precision)
{
struct timeval tv;
long tv_nsec;
if (ts_nanosec == 0)
return (struct timeval) { 0, 0 };
tv.tv_sec = ts_nanosec / _NSEC_PER_SEC;
tv_nsec = (ts_nanosec % _NSEC_PER_SEC);
/* libpcap expects tv_usec to be nanos if using nanosecond precision. */
if (tstamp_precision == PCAP_TSTAMP_PRECISION_NANO)
tv.tv_usec = tv_nsec;
else
tv.tv_usec = tv_nsec / 1000;
return tv;
}
static int
snf_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
struct pcap_snf *ps = p->priv;
struct pcap_pkthdr hdr;
int i, flags, err, caplen, n;
struct snf_recv_req req;
int nonblock, timeout;
if (!p)
return -1;
n = 0;
timeout = ps->snf_timeout;
while (n < cnt || PACKET_COUNT_IS_UNLIMITED(cnt)) {
/*
* Has "pcap_breakloop()" been called?
*/
if (p->break_loop) {
if (n == 0) {
p->break_loop = 0;
return (-2);
} else {
return (n);
}
}
err = snf_ring_recv(ps->snf_ring, timeout, &req);
if (err) {
if (err == EBUSY || err == EAGAIN) {
return (n);
}
else if (err == EINTR) {
timeout = 0;
continue;
}
else {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snf_read: %s",
pcap_strerror(err));
return -1;
}
}
caplen = req.length;
if (caplen > p->snapshot)
caplen = p->snapshot;
if ((p->fcode.bf_insns == NULL) ||
bpf_filter(p->fcode.bf_insns, req.pkt_addr, req.length, caplen)) {
hdr.ts = snf_timestamp_to_timeval(req.timestamp, p->opt.tstamp_precision);
hdr.caplen = caplen;
hdr.len = req.length;
callback(user, &hdr, req.pkt_addr);
}
n++;
/* After one successful packet is received, we won't block
* again for that timeout. */
if (timeout != 0)
timeout = 0;
}
return (n);
}
static int
snf_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;
return (0);
}
static int
snf_inject(pcap_t *p, const void *buf _U_, size_t size _U_)
{
#ifdef SNF_HAVE_INJECT_API
struct pcap_snf *ps = p->priv;
int rc;
if (ps->snf_inj == NULL) {
rc = snf_inject_open(ps->snf_boardnum, 0, &ps->snf_inj);
if (rc) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"snf_inject_open: %s", pcap_strerror(rc));
return (-1);
}
}
rc = snf_inject_send(ps->snf_inj, -1, 0, buf, size);
if (!rc) {
return (size);
}
else {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "snf_inject_send: %s",
pcap_strerror(rc));
return (-1);
}
#else
strlcpy(p->errbuf, "Sending packets isn't supported with this snf version",
PCAP_ERRBUF_SIZE);
return (-1);
#endif
}
static int
snf_activate(pcap_t* p)
{
struct pcap_snf *ps = p->priv;
char *device = p->opt.source;
const char *nr = NULL;
int err;
int flags = -1, ring_id = -1;
if (device == NULL) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"device is NULL: %s", pcap_strerror(errno));
return -1;
}
/* In Libpcap, we set pshared by default if NUM_RINGS is set to > 1.
* Since libpcap isn't thread-safe */
if ((nr = getenv("SNF_FLAGS")) && *nr)
flags = strtol(nr, NULL, 0);
else if ((nr = getenv("SNF_NUM_RINGS")) && *nr && atoi(nr) > 1)
flags = SNF_F_PSHARED;
else
nr = NULL;
err = snf_open(ps->snf_boardnum,
0, /* let SNF API parse SNF_NUM_RINGS, if set */
NULL, /* default RSS, or use SNF_RSS_FLAGS env */
0, /* default to SNF_DATARING_SIZE from env */
flags, /* may want pshared */
&ps->snf_handle);
if (err != 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"snf_open failed: %s", pcap_strerror(err));
return -1;
}
if ((nr = getenv("SNF_PCAP_RING_ID")) && *nr) {
ring_id = (int) strtol(nr, NULL, 0);
}
err = snf_ring_open_id(ps->snf_handle, ring_id, &ps->snf_ring);
if (err != 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"snf_ring_open_id(ring=%d) failed: %s",
ring_id, pcap_strerror(err));
return -1;
}
if (p->opt.timeout <= 0)
ps->snf_timeout = -1;
else
ps->snf_timeout = p->opt.timeout;
err = snf_start(ps->snf_handle);
if (err != 0) {
snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
"snf_start failed: %s", pcap_strerror(err));
return -1;
}
/*
* "select()" and "poll()" don't work on snf descriptors.
*/
p->selectable_fd = -1;
p->linktype = DLT_EN10MB;
p->read_op = snf_read;
p->inject_op = snf_inject;
p->setfilter_op = snf_setfilter;
p->setdirection_op = NULL; /* Not implemented.*/
p->set_datalink_op = snf_set_datalink;
p->getnonblock_op = snf_getnonblock;
p->setnonblock_op = snf_setnonblock;
p->stats_op = snf_pcap_stats;
p->cleanup_op = snf_platform_cleanup;
#ifdef SNF_HAVE_INJECT_API
ps->snf_inj = NULL;
#endif
return 0;
}
#define MAX_DESC_LENGTH 128
int
snf_findalldevs(pcap_if_t **devlistp, char *errbuf)
{
pcap_if_t *devlist = NULL,*curdev,*prevdev;
pcap_addr_t *curaddr;
struct snf_ifaddrs *ifaddrs, *ifa;
char desc[MAX_DESC_LENGTH];
int ret;
if (snf_init(SNF_VERSION_API))
return (-1);
if (snf_getifaddrs(&ifaddrs) || ifaddrs == NULL)
{
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"snf_getifaddrs: %s", pcap_strerror(errno));
return (-1);
}
ifa = ifaddrs;
while (ifa)
{
/*
* Allocate a new entry
*/
curdev = (pcap_if_t *)malloc(sizeof(pcap_if_t));
if (curdev == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"snf_findalldevs malloc: %s", pcap_strerror(errno));
return (-1);
}
if (devlist == NULL) /* save first entry */
devlist = curdev;
else
prevdev->next = curdev;
/*
* Fill in the entry.
*/
curdev->next = NULL;
curdev->name = strdup(ifa->snf_ifa_name);
if (curdev->name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"snf_findalldevs strdup: %s", pcap_strerror(errno));
free(curdev);
return (-1);
}
(void)snprintf(desc,MAX_DESC_LENGTH,"Myricom snf%d",
ifa->snf_ifa_portnum);
curdev->description = strdup(desc);
if (curdev->description == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"snf_findalldevs strdup1: %s", pcap_strerror(errno));
free(curdev->name);
free(curdev);
return (-1);
}
curdev->addresses = NULL;
curdev->flags = 0;
curaddr = (pcap_addr_t *)malloc(sizeof(pcap_addr_t));
if (curaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"snf_findalldevs malloc1: %s", pcap_strerror(errno));
free(curdev->description);
free(curdev->name);
free(curdev);
return (-1);
}
curdev->addresses = curaddr;
curaddr->next = NULL;
curaddr->addr = (struct sockaddr*)malloc(sizeof(struct sockaddr_storage));
if (curaddr->addr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc2: %s", pcap_strerror(errno));
free(curdev->description);
free(curdev->name);
free(curaddr);
free(curdev);
return (-1);
}
curaddr->addr->sa_family = AF_INET;
curaddr->netmask = NULL;
curaddr->broadaddr = NULL;
curaddr->dstaddr = NULL;
curaddr->next = NULL;
prevdev = curdev;
ifa = ifa->snf_ifa_next;
}
snf_freeifaddrs(ifaddrs);
*devlistp = devlist;
/*
* There are no platform-specific devices since each device
* exists as a regular Ethernet device.
*/
return 0;
}
pcap_t *
snf_create(const char *device, char *ebuf, int *is_ours)
{
pcap_t *p;
int boardnum = -1;
struct snf_ifaddrs *ifaddrs, *ifa;
size_t devlen;
struct pcap_snf *ps;
if (snf_init(SNF_VERSION_API)) {
/* Can't initialize the API, so no SNF devices */
*is_ours = 0;
return NULL;
}
/*
* Match a given interface name to our list of interface names, from
* which we can obtain the intended board number
*/
if (snf_getifaddrs(&ifaddrs) || ifaddrs == NULL) {
/* Can't get SNF addresses */
*is_ours = 0;
return NULL;
}
devlen = strlen(device) + 1;
ifa = ifaddrs;
while (ifa) {
if (!strncmp(device, ifa->snf_ifa_name, devlen)) {
boardnum = ifa->snf_ifa_boardnum;
break;
}
ifa = ifa->snf_ifa_next;
}
snf_freeifaddrs(ifaddrs);
if (ifa == NULL) {
/*
* If we can't find the device by name, support the name "snfX"
* and "snf10gX" where X is the board number.
*/
if (sscanf(device, "snf10g%d", &boardnum) != 1 &&
sscanf(device, "snf%d", &boardnum) != 1) {
/* Nope, not a supported name */
*is_ours = 0;
return NULL;
}
}
/* OK, it's probably ours. */
*is_ours = 1;
p = pcap_create_common(device, ebuf, sizeof (struct pcap_snf));
if (p == NULL)
return NULL;
ps = p->priv;
/*
* We support microsecond and nanosecond time stamps.
*/
p->tstamp_precision_count = 2;
p->tstamp_precision_list = malloc(2 * sizeof(u_int));
if (p->tstamp_precision_list == NULL) {
snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
pcap_strerror(errno));
if (p->tstamp_type_list != NULL)
free(p->tstamp_type_list);
free(p);
return NULL;
}
p->tstamp_precision_list[0] = PCAP_TSTAMP_PRECISION_MICRO;
p->tstamp_precision_list[1] = PCAP_TSTAMP_PRECISION_NANO;
p->activate_op = snf_activate;
ps->snf_boardnum = boardnum;
return p;
}