/*
* (C) 2011 Luigi Rizzo
*
* BSD license
*
* A simple library that maps some pcap functions onto netmap
* This is not 100% complete but enough to let tcpdump, trafshow
* and other apps work.
*
* $FreeBSD$
*/
#include <errno.h>
#include <signal.h> /* signal */
#include <stdlib.h>
#include <stdio.h>
#include <string.h> /* strcmp */
#include <fcntl.h> /* open */
#include <unistd.h> /* close */
#include <sys/endian.h> /* le64toh */
#include <sys/mman.h> /* PROT_* */
#include <sys/ioctl.h> /* ioctl */
#include <machine/param.h>
#include <sys/poll.h>
#include <sys/socket.h> /* sockaddr.. */
#include <arpa/inet.h> /* ntohs */
#include <net/if.h> /* ifreq */
#include <net/ethernet.h>
#include <net/netmap.h>
#include <net/netmap_user.h>
#include <netinet/in.h> /* sockaddr_in */
#include <sys/socket.h>
#include <ifaddrs.h>
#define MIN(a, b) ((a) < (b) ? (a) : (b))
char *version = "$Id$";
int verbose = 0;
/* debug support */
#define ND(format, ...) do {} while (0)
#define D(format, ...) do { \
if (verbose) \
fprintf(stderr, "--- %s [%d] " format "\n", \
__FUNCTION__, __LINE__, ##__VA_ARGS__); \
} while (0)
/*
* We redefine here a number of structures that are in pcap.h
* so we can compile this file without the system header.
*/
#ifndef PCAP_ERRBUF_SIZE
#define PCAP_ERRBUF_SIZE 128
/*
* Each packet is accompanied by a header including the timestamp,
* captured size and actual size.
*/
struct pcap_pkthdr {
struct timeval ts; /* time stamp */
uint32_t caplen; /* length of portion present */
uint32_t len; /* length this packet (off wire) */
};
typedef struct pcap_if pcap_if_t;
/*
* Representation of an interface address.
*/
struct pcap_addr {
struct pcap_addr *next;
struct sockaddr *addr; /* address */
struct sockaddr *netmask; /* netmask for the above */
struct sockaddr *broadaddr; /* broadcast addr for the above */
struct sockaddr *dstaddr; /* P2P dest. address for the above */
};
struct pcap_if {
struct pcap_if *next;
char *name; /* name to hand to "pcap_open_live()" */
char *description; /* textual description of interface, or NULL */
struct pcap_addr *addresses;
uint32_t flags; /* PCAP_IF_ interface flags */
};
/*
* We do not support stats (yet)
*/
struct pcap_stat {
u_int ps_recv; /* number of packets received */
u_int ps_drop; /* number of packets dropped */
u_int ps_ifdrop; /* drops by interface XXX not yet supported */
#ifdef WIN32
u_int bs_capt; /* number of packets that reach the app. */
#endif /* WIN32 */
};
typedef void pcap_t;
typedef enum {
PCAP_D_INOUT = 0,
PCAP_D_IN,
PCAP_D_OUT
} pcap_direction_t;
typedef void (*pcap_handler)(u_char *user,
const struct pcap_pkthdr *h, const u_char *bytes);
char errbuf[PCAP_ERRBUF_SIZE];
pcap_t *pcap_open_live(const char *device, int snaplen,
int promisc, int to_ms, char *errbuf);
int pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf);
void pcap_close(pcap_t *p);
int pcap_get_selectable_fd(pcap_t *p);
int pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user);
int pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf);
int pcap_setdirection(pcap_t *p, pcap_direction_t d);
char *pcap_lookupdev(char *errbuf);
int pcap_inject(pcap_t *p, const void *buf, size_t size);
int pcap_fileno(pcap_t *p);
struct eproto {
const char *s;
u_short p;
};
#endif /* !PCAP_ERRBUF_SIZE */
#ifdef __PIC__
/*
* build as a shared library
*/
char pcap_version[] = "libnetmap version 0.3";
/*
* Our equivalent of pcap_t
*/
struct my_ring {
struct nmreq nmr;
int fd;
char *mem; /* userspace mmap address */
u_int memsize;
u_int queueid;
u_int begin, end; /* first..last+1 rings to check */
struct netmap_if *nifp;
int snaplen;
char *errbuf;
int promisc;
int to_ms;
struct pcap_pkthdr hdr;
uint32_t if_flags;
uint32_t if_reqcap;
uint32_t if_curcap;
struct pcap_stat st;
char msg[PCAP_ERRBUF_SIZE];
};
static int
do_ioctl(struct my_ring *me, int what)
{
struct ifreq ifr;
int error;
bzero(&ifr, sizeof(ifr));
strncpy(ifr.ifr_name, me->nmr.nr_name, sizeof(ifr.ifr_name));
switch (what) {
case SIOCSIFFLAGS:
D("call SIOCSIFFLAGS 0x%x", me->if_flags);
ifr.ifr_flagshigh = (me->if_flags >> 16) & 0xffff;
ifr.ifr_flags = me->if_flags & 0xffff;
break;
case SIOCSIFCAP:
ifr.ifr_reqcap = me->if_reqcap;
ifr.ifr_curcap = me->if_curcap;
break;
}
error = ioctl(me->fd, what, &ifr);
if (error) {
D("ioctl 0x%x error %d", what, error);
return error;
}
switch (what) {
case SIOCSIFFLAGS:
case SIOCGIFFLAGS:
me->if_flags = (ifr.ifr_flagshigh << 16) |
(0xffff & ifr.ifr_flags);
D("flags are L 0x%x H 0x%x 0x%x",
(uint16_t)ifr.ifr_flags,
(uint16_t)ifr.ifr_flagshigh, me->if_flags);
break;
case SIOCGIFCAP:
me->if_reqcap = ifr.ifr_reqcap;
me->if_curcap = ifr.ifr_curcap;
D("curcap are 0x%x", me->if_curcap);
break;
}
return 0;
}
/*
* open a device. if me->mem is null then do an mmap.
*/
static int
netmap_open(struct my_ring *me, int ringid)
{
int fd, err, l;
u_int i;
struct nmreq req;
me->fd = fd = open("/dev/netmap", O_RDWR);
if (fd < 0) {
D("Unable to open /dev/netmap");
return (-1);
}
bzero(&req, sizeof(req));
strncpy(req.nr_name, me->nmr.nr_name, sizeof(req.nr_name));
req.nr_ringid = ringid;
err = ioctl(fd, NIOCGINFO, &req);
if (err) {
D("cannot get info on %s", me->nmr.nr_name);
goto error;
}
me->memsize = l = req.nr_memsize;
ND("memsize is %d MB", l>>20);
err = ioctl(fd, NIOCREGIF, &req);
if (err) {
D("Unable to register %s", me->nmr.nr_name);
goto error;
}
if (me->mem == NULL) {
me->mem = mmap(0, l, PROT_WRITE | PROT_READ, MAP_SHARED, fd, 0);
if (me->mem == MAP_FAILED) {
D("Unable to mmap");
me->mem = NULL;
goto error;
}
}
me->nifp = NETMAP_IF(me->mem, req.nr_offset);
me->queueid = ringid;
if (ringid & NETMAP_SW_RING) {
me->begin = req.nr_numrings;
me->end = me->begin + 1;
} else if (ringid & NETMAP_HW_RING) {
me->begin = ringid & NETMAP_RING_MASK;
me->end = me->begin + 1;
} else {
me->begin = 0;
me->end = req.nr_numrings;
}
/* request timestamps for packets */
for (i = me->begin; i < me->end; i++) {
struct netmap_ring *ring = NETMAP_RXRING(me->nifp, i);
ring->flags = NR_TIMESTAMP;
}
//me->tx = NETMAP_TXRING(me->nifp, 0);
return (0);
error:
close(me->fd);
return -1;
}
/*
* There is a set of functions that tcpdump expects even if probably
* not used
*/
struct eproto eproto_db[] = {
{ "ip", ETHERTYPE_IP },
{ "arp", ETHERTYPE_ARP },
{ (char *)0, 0 }
};
int
pcap_findalldevs(pcap_if_t **alldevsp, __unused char *errbuf)
{
struct ifaddrs *i_head, *i;
pcap_if_t *top = NULL, *cur;
struct pcap_addr *tail = NULL;
int l;
D("listing all devs");
*alldevsp = NULL;
i_head = NULL;
if (getifaddrs(&i_head)) {
D("cannot get if addresses");
return -1;
}
for (i = i_head; i; i = i->ifa_next) {
//struct ifaddrs *ifa;
struct pcap_addr *pca;
//struct sockaddr *sa;
D("got interface %s", i->ifa_name);
if (!top || strcmp(top->name, i->ifa_name)) {
/* new interface */
l = sizeof(*top) + strlen(i->ifa_name) + 1;
cur = calloc(1, l);
if (cur == NULL) {
D("no space for if descriptor");
continue;
}
cur->name = (char *)(cur + 1);
//cur->flags = i->ifa_flags;
strcpy(cur->name, i->ifa_name);
cur->description = NULL;
cur->next = top;
top = cur;
tail = NULL;
}
/* now deal with addresses */
D("%s addr family %d len %d %s %s",
top->name,
i->ifa_addr->sa_family, i->ifa_addr->sa_len,
i->ifa_netmask ? "Netmask" : "",
i->ifa_broadaddr ? "Broadcast" : "");
l = sizeof(struct pcap_addr) +
(i->ifa_addr ? i->ifa_addr->sa_len:0) +
(i->ifa_netmask ? i->ifa_netmask->sa_len:0) +
(i->ifa_broadaddr? i->ifa_broadaddr->sa_len:0);
pca = calloc(1, l);
if (pca == NULL) {
D("no space for if addr");
continue;
}
#define SA_NEXT(x) ((struct sockaddr *)((char *)(x) + (x)->sa_len))
pca->addr = (struct sockaddr *)(pca + 1);
bcopy(i->ifa_addr, pca->addr, i->ifa_addr->sa_len);
if (i->ifa_netmask) {
pca->netmask = SA_NEXT(pca->addr);
bcopy(i->ifa_netmask, pca->netmask, i->ifa_netmask->sa_len);
if (i->ifa_broadaddr) {
pca->broadaddr = SA_NEXT(pca->netmask);
bcopy(i->ifa_broadaddr, pca->broadaddr, i->ifa_broadaddr->sa_len);
}
}
if (tail == NULL) {
top->addresses = pca;
} else {
tail->next = pca;
}
tail = pca;
}
freeifaddrs(i_head);
*alldevsp = top;
return 0;
}
void pcap_freealldevs(__unused pcap_if_t *alldevs)
{
D("unimplemented");
}
char *
pcap_lookupdev(char *buf)
{
D("%s", buf);
strcpy(buf, "/dev/netmap");
return buf;
}
pcap_t *
pcap_create(const char *source, char *errbuf)
{
D("src %s (call open liveted)", source);
return pcap_open_live(source, 0, 1, 100, errbuf);
}
int
pcap_activate(pcap_t *p)
{
D("pcap %p running", p);
return 0;
}
int
pcap_can_set_rfmon(__unused pcap_t *p)
{
D("");
return 0; /* no we can't */
}
int
pcap_set_snaplen(pcap_t *p, int snaplen)
{
struct my_ring *me = p;
D("len %d", snaplen);
me->snaplen = snaplen;
return 0;
}
int
pcap_snapshot(pcap_t *p)
{
struct my_ring *me = p;
D("len %d", me->snaplen);
return me->snaplen;
}
int
pcap_lookupnet(const char *device, uint32_t *netp,
uint32_t *maskp, __unused char *errbuf)
{
D("device %s", device);
inet_aton("10.0.0.255", (struct in_addr *)netp);
inet_aton("255.255.255.0",(struct in_addr *) maskp);
return 0;
}
int
pcap_set_promisc(pcap_t *p, int promisc)
{
struct my_ring *me = p;
D("promisc %d", promisc);
if (do_ioctl(me, SIOCGIFFLAGS))
D("SIOCGIFFLAGS failed");
if (promisc) {
me->if_flags |= IFF_PPROMISC;
} else {
me->if_flags &= ~IFF_PPROMISC;
}
if (do_ioctl(me, SIOCSIFFLAGS))
D("SIOCSIFFLAGS failed");
return 0;
}
int
pcap_set_timeout(pcap_t *p, int to_ms)
{
struct my_ring *me = p;
D("%d ms", to_ms);
me->to_ms = to_ms;
return 0;
}
struct bpf_program;
int
pcap_compile(__unused pcap_t *p, __unused struct bpf_program *fp,
const char *str, __unused int optimize, __unused uint32_t netmask)
{
D("%s", str);
return 0;
}
int
pcap_setfilter(__unused pcap_t *p, __unused struct bpf_program *fp)
{
D("");
return 0;
}
int
pcap_datalink(__unused pcap_t *p)
{
D("");
return 1; // ethernet
}
const char *
pcap_datalink_val_to_name(int dlt)
{
D("%d", dlt);
return "DLT_EN10MB";
}
const char *
pcap_datalink_val_to_description(int dlt)
{
D("%d", dlt);
return "Ethernet link";
}
struct pcap_stat;
int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
struct my_ring *me = p;
ND("");
me->st.ps_recv += 10;
*ps = me->st;
sprintf(me->msg, "stats not supported");
return -1;
};
char *
pcap_geterr(pcap_t *p)
{
struct my_ring *me = p;
D("");
return me->msg;
}
pcap_t *
pcap_open_live(const char *device, __unused int snaplen,
int promisc, int to_ms, __unused char *errbuf)
{
struct my_ring *me;
D("request to open %s", device);
me = calloc(1, sizeof(*me));
if (me == NULL) {
D("failed to allocate struct for %s", device);
return NULL;
}
strncpy(me->nmr.nr_name, device, sizeof(me->nmr.nr_name));
if (netmap_open(me, 0)) {
D("error opening %s", device);
free(me);
return NULL;
}
me->to_ms = to_ms;
if (do_ioctl(me, SIOCGIFFLAGS))
D("SIOCGIFFLAGS failed");
if (promisc) {
me->if_flags |= IFF_PPROMISC;
if (do_ioctl(me, SIOCSIFFLAGS))
D("SIOCSIFFLAGS failed");
}
if (do_ioctl(me, SIOCGIFCAP))
D("SIOCGIFCAP failed");
me->if_reqcap &= ~(IFCAP_HWCSUM | IFCAP_TSO | IFCAP_TOE);
if (do_ioctl(me, SIOCSIFCAP))
D("SIOCSIFCAP failed");
return (pcap_t *)me;
}
void
pcap_close(pcap_t *p)
{
struct my_ring *me = p;
D("");
if (!me)
return;
if (me->mem)
munmap(me->mem, me->memsize);
/* restore original flags ? */
ioctl(me->fd, NIOCUNREGIF, NULL);
close(me->fd);
bzero(me, sizeof(*me));
free(me);
}
int
pcap_fileno(pcap_t *p)
{
struct my_ring *me = p;
D("returns %d", me->fd);
return me->fd;
}
int
pcap_get_selectable_fd(pcap_t *p)
{
struct my_ring *me = p;
ND("");
return me->fd;
}
int
pcap_setnonblock(__unused pcap_t *p, int nonblock, __unused char *errbuf)
{
D("mode is %d", nonblock);
return 0; /* ignore */
}
int
pcap_setdirection(__unused pcap_t *p, __unused pcap_direction_t d)
{
D("");
return 0; /* ignore */
};
int
pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
struct my_ring *me = p;
int got = 0;
u_int si;
ND("cnt %d", cnt);
/* scan all rings */
for (si = me->begin; si < me->end; si++) {
struct netmap_ring *ring = NETMAP_RXRING(me->nifp, si);
ND("ring has %d pkts", ring->avail);
if (ring->avail == 0)
continue;
me->hdr.ts = ring->ts;
while ((cnt == -1 || cnt != got) && ring->avail > 0) {
u_int i = ring->cur;
u_int idx = ring->slot[i].buf_idx;
if (idx < 2) {
D("%s bogus RX index %d at offset %d",
me->nifp->ni_name, idx, i);
sleep(2);
}
u_char *buf = (u_char *)NETMAP_BUF(ring, idx);
me->hdr.len = me->hdr.caplen = ring->slot[i].len;
// D("call %p len %d", p, me->hdr.len);
callback(user, &me->hdr, buf);
ring->cur = NETMAP_RING_NEXT(ring, i);
ring->avail--;
got++;
}
}
return got;
}
int
pcap_inject(pcap_t *p, const void *buf, size_t size)
{
struct my_ring *me = p;
u_int si;
ND("cnt %d", cnt);
/* scan all rings */
for (si = me->begin; si < me->end; si++) {
struct netmap_ring *ring = NETMAP_TXRING(me->nifp, si);
ND("ring has %d pkts", ring->avail);
if (ring->avail == 0)
continue;
u_int i = ring->cur;
u_int idx = ring->slot[i].buf_idx;
if (idx < 2) {
D("%s bogus TX index %d at offset %d",
me->nifp->ni_name, idx, i);
sleep(2);
}
u_char *dst = (u_char *)NETMAP_BUF(ring, idx);
ring->slot[i].len = size;
bcopy(buf, dst, size);
ring->cur = NETMAP_RING_NEXT(ring, i);
ring->avail--;
// if (ring->avail == 0) ioctl(me->fd, NIOCTXSYNC, NULL);
return size;
}
errno = ENOBUFS;
return -1;
}
int
pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
struct my_ring *me = p;
struct pollfd fds[1];
int i;
ND("cnt %d", cnt);
memset(fds, 0, sizeof(fds));
fds[0].fd = me->fd;
fds[0].events = (POLLIN);
while (cnt == -1 || cnt > 0) {
if (poll(fds, 1, me->to_ms) <= 0) {
D("poll error/timeout");
continue;
}
i = pcap_dispatch(p, cnt, callback, user);
if (cnt > 0)
cnt -= i;
}
return 0;
}
#endif /* __PIC__ */
#ifndef __PIC__
void do_send(u_char *user, const struct pcap_pkthdr *h, const u_char *buf)
{
pcap_inject((pcap_t *)user, buf, h->caplen);
}
/*
* a simple pcap test program, bridge between two interfaces.
*/
int
main(int argc, char **argv)
{
pcap_t *p0, *p1;
int burst = 1024;
struct pollfd pollfd[2];
fprintf(stderr, "%s %s built %s %s\n",
argv[0], version, __DATE__, __TIME__);
while (argc > 1 && !strcmp(argv[1], "-v")) {
verbose++;
argv++;
argc--;
}
if (argc < 3 || argc > 4 || !strcmp(argv[1], argv[2])) {
D("Usage: %s IFNAME1 IFNAME2 [BURST]", argv[0]);
return (1);
}
if (argc > 3)
burst = atoi(argv[3]);
p0 = pcap_open_live(argv[1], 0, 1, 100, NULL);
p1 = pcap_open_live(argv[2], 0, 1, 100, NULL);
D("%s", version);
D("open returns %p %p", p0, p1);
if (!p0 || !p1)
return(1);
bzero(pollfd, sizeof(pollfd));
pollfd[0].fd = pcap_fileno(p0);
pollfd[1].fd = pcap_fileno(p1);
pollfd[0].events = pollfd[1].events = POLLIN;
for (;;) {
/* do i need to reset ? */
pollfd[0].revents = pollfd[1].revents = 0;
int ret = poll(pollfd, 2, 1000);
if (ret <= 0 || verbose)
D("poll %s [0] ev %x %x [1] ev %x %x",
ret <= 0 ? "timeout" : "ok",
pollfd[0].events,
pollfd[0].revents,
pollfd[1].events,
pollfd[1].revents);
if (ret < 0)
continue;
if (pollfd[0].revents & POLLIN)
pcap_dispatch(p0, burst, do_send, p1);
if (pollfd[1].revents & POLLIN)
pcap_dispatch(p1, burst, do_send, p0);
}
return (0);
}
#endif /* !__PIC__ */
