Date: Fri, 3 Oct 2014 00:12:23 +0200 From: Luigi Rizzo <rizzo@iet.unipi.it> To: current@freebsd.org, delphij@freebsd.org, net@freebsd.org Subject: adding netmap support to libpcap in FreeBSD Message-ID: <20141002221223.GA37059@onelab2.iet.unipi.it>
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I want to bring netmap support into our libpcap.
The patch is attached, and as you can see changes are trivial,
with the new methods contained in a new file pcap-netmap.c
I would love to upstream this to the libpcap project (I even have
the necessary configure* patches, see code.google.com/p/netmap-libpcap),
but I don't see that happening soon:
when I tried last winter there was hardly any interest, and then a
bikeshed on the absence of a findalldevs method (which i cannot
provide as the set would be infinite, unlike my patience :)
So for the time being I plan to put the new source file pcap-netmap.c
into lib/libpcap instead of contrib/libpcap .
Let me know if you have objections.
cheers
luigi
Index: contrib/libpcap/inet.c
===================================================================
--- contrib/libpcap/inet.c (revision 272410)
+++ contrib/libpcap/inet.c (working copy)
@@ -737,6 +737,10 @@
#ifdef PCAP_SUPPORT_USB
|| strstr(device, "usbmon") != NULL
#endif
+#ifdef PCAP_SUPPORT_NETMAP
+ || !strncmp(device, "netmap:", 7)
+ || !strncmp(device, "vale", 4)
+#endif
#ifdef HAVE_SNF_API
|| strstr(device, "snf") != NULL
#endif
Index: contrib/libpcap/pcap.c
===================================================================
--- contrib/libpcap/pcap.c (revision 272410)
+++ contrib/libpcap/pcap.c (working copy)
@@ -106,6 +106,10 @@
#include "pcap-netfilter-linux.h"
#endif
+#ifdef PCAP_SUPPORT_NETMAP
+pcap_t* pcap_netmap_create(const char *device, char *ebuf, int *is_ours);
+#endif
+
int
pcap_not_initialized(pcap_t *pcap)
{
@@ -301,6 +305,9 @@
int (*findalldevs_op)(pcap_if_t **, char *);
pcap_t *(*create_op)(const char *, char *, int *);
} capture_source_types[] = {
+#ifdef PCAP_SUPPORT_NETMAP
+ { NULL, pcap_netmap_create },
+#endif
#ifdef HAVE_DAG_API
{ dag_findalldevs, dag_create },
#endif
Index: lib/libpcap/Makefile
===================================================================
--- lib/libpcap/Makefile (revision 272410)
+++ lib/libpcap/Makefile (working copy)
@@ -7,6 +7,7 @@
LIB= pcap
SRCS= grammar.y tokdefs.h version.h pcap-bpf.c \
+ pcap-netmap.c \
pcap.c pcap-common.c inet.c fad-getad.c gencode.c optimize.c nametoaddr.c \
etherent.c savefile.c bpf_filter.c bpf_image.c bpf_dump.c \
scanner.l sf-pcap.c sf-pcap-ng.c version.c
Index: lib/libpcap/config.h
===================================================================
--- lib/libpcap/config.h (revision 272410)
+++ lib/libpcap/config.h (working copy)
@@ -271,6 +271,9 @@
/* target host supports USB sniffing */
/* #undef PCAP_SUPPORT_USB */
+/* target host supports netmap */
+#define PCAP_SUPPORT_NETMAP 1
+
/* include ACN support */
/* #undef SITA */
Index: lib/libpcap/pcap-netmap.c
===================================================================
--- /dev/null 2014-10-02 23:33:00.000000000 +0200
+++ lib/libpcap/pcap-netmap.c 2014-10-02 23:37:33.000000000 +0200
@@ -0,0 +1,265 @@
+/*
+ * Copyright (C) 2014 Luigi Rizzo. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``S IS''AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <poll.h>
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define NETMAP_WITH_LIBS
+#include <net/netmap_user.h>
+
+#include "pcap-int.h"
+
+/*
+ * This code is meant to build also on older versions of libpcap.
+ *
+ * older libpcap miss p->priv, use p->md.device instead (and allocate).
+ * Also opt.timeout was in md.timeout before.
+ * Use #define PCAP_IF_UP to discriminate
+ */
+#ifdef PCAP_IF_UP
+#define NM_PRIV(p) ((struct pcap_netmap *)(p->priv))
+#define the_timeout opt.timeout
+#else
+#define HAVE_NO_PRIV
+#define NM_PRIV(p) ((struct pcap_netmap *)(p->md.device))
+#define SET_PRIV(p, x) p->md.device = (void *)x
+#define the_timeout md.timeout
+#endif
+
+#if defined (linux)
+/* On FreeBSD we use IFF_PPROMISC which is in ifr_flagshigh.
+ * remap to IFF_PROMISC on linux
+ */
+#define IFF_PPROMISC IFF_PROMISC
+#define ifr_flagshigh ifr_flags
+#endif /* linux */
+
+struct pcap_netmap {
+ struct nm_desc *d; /* pointer returned by nm_open() */
+ pcap_handler cb; /* callback and argument */
+ u_char *cb_arg;
+ int must_clear_promisc; /* flag */
+ uint64_t rx_pkts; /* # of pkts received before the filter */
+};
+
+static int
+pcap_netmap_stats(pcap_t *p, struct pcap_stat *ps)
+{
+ struct pcap_netmap *pn = NM_PRIV(p);
+
+ ps->ps_recv = pn->rx_pkts;
+ ps->ps_drop = 0;
+ ps->ps_ifdrop = 0;
+ return 0;
+}
+
+static void
+pcap_netmap_filter(u_char *arg, struct pcap_pkthdr *h, const u_char *buf)
+{
+ pcap_t *p = (pcap_t *)arg;
+ struct pcap_netmap *pn = NM_PRIV(p);
+
+ ++pn->rx_pkts;
+ if (bpf_filter(p->fcode.bf_insns, buf, h->len, h->caplen))
+ pn->cb(pn->cb_arg, h, buf);
+}
+
+static int
+pcap_netmap_dispatch(pcap_t *p, int cnt, pcap_handler cb, u_char *user)
+{
+ int ret;
+ struct pcap_netmap *pn = NM_PRIV(p);
+ struct nm_desc *d = pn->d;
+ struct pollfd pfd = { .fd = p->fd, .events = POLLIN, .revents = 0 };
+
+ pn->cb = cb;
+ pn->cb_arg = user;
+
+ for (;;) {
+ if (p->break_loop) {
+ p->break_loop = 0;
+ return PCAP_ERROR_BREAK;
+ }
+ /* nm_dispatch won't run forever */
+
+ ret = nm_dispatch((void *)d, cnt, (void *)pcap_netmap_filter, (void *)p);
+ if (ret != 0)
+ break;
+ errno = 0;
+ ret = poll(&pfd, 1, p->the_timeout);
+ }
+ return ret;
+}
+
+/* XXX need to check the NIOCTXSYNC/poll */
+static int
+pcap_netmap_inject(pcap_t *p, const void *buf, size_t size)
+{
+ struct nm_desc *d = NM_PRIV(p)->d;
+
+ return nm_inject(d, buf, size);
+}
+
+static int
+pcap_netmap_ioctl(pcap_t *p, u_long what, uint32_t *if_flags)
+{
+ struct pcap_netmap *pn = NM_PRIV(p);
+ struct nm_desc *d = pn->d;
+ struct ifreq ifr;
+ int error, fd = d->fd;
+
+#ifdef linux
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd < 0) {
+ fprintf(stderr, "Error: cannot get device control socket.\n");
+ return -1;
+ }
+#endif /* linux */
+ bzero(&ifr, sizeof(ifr));
+ strncpy(ifr.ifr_name, d->req.nr_name, sizeof(ifr.ifr_name));
+ switch (what) {
+ case SIOCSIFFLAGS:
+ ifr.ifr_flags = *if_flags;
+ ifr.ifr_flagshigh = *if_flags >> 16;
+ break;
+ }
+ error = ioctl(fd, what, &ifr);
+ if (error)
+ return -1;
+ switch (what) {
+ case SIOCGIFFLAGS:
+ *if_flags = ifr.ifr_flags | (ifr.ifr_flagshigh << 16);
+ }
+ return 0;
+}
+
+static void
+pcap_netmap_close(pcap_t *p)
+{
+ struct pcap_netmap *pn = NM_PRIV(p);
+ struct nm_desc *d = pn->d;
+ uint32_t if_flags = 0;
+
+ if (pn->must_clear_promisc) {
+ pcap_netmap_ioctl(p, SIOCGIFFLAGS, &if_flags); /* fetch flags */
+ if (if_flags & IFF_PPROMISC) {
+ if_flags &= ~IFF_PPROMISC;
+ pcap_netmap_ioctl(p, SIOCSIFFLAGS, &if_flags);
+ }
+ }
+ nm_close(d);
+#ifdef HAVE_NO_PRIV
+ free(pn);
+ SET_PRIV(p, NULL); // unnecessary
+#endif
+ pcap_cleanup_live_common(p);
+}
+
+static int
+pcap_netmap_activate(pcap_t *p)
+{
+ struct pcap_netmap *pn = NM_PRIV(p);
+ struct nm_desc *d = nm_open(p->opt.source, NULL, 0, NULL);
+ uint32_t if_flags = 0;
+
+ if (d == NULL) {
+ snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
+ "netmap open: cannot access %s: %s\n",
+ p->opt.source, pcap_strerror(errno));
+#ifdef HAVE_NO_PRIV
+ free(pn);
+ SET_PRIV(p, NULL); // unnecessary
+#endif
+ pcap_cleanup_live_common(p);
+ return (PCAP_ERROR);
+ }
+ if (0)
+ fprintf(stderr, "%s device %s priv %p fd %d ports %d..%d\n",
+ __FUNCTION__, p->opt.source, d, d->fd,
+ d->first_rx_ring, d->last_rx_ring);
+ pn->d = d;
+ p->fd = d->fd;
+ if (p->opt.promisc && !(d->req.nr_ringid & NETMAP_SW_RING)) {
+ pcap_netmap_ioctl(p, SIOCGIFFLAGS, &if_flags); /* fetch flags */
+ if (!(if_flags & IFF_PPROMISC)) {
+ pn->must_clear_promisc = 1;
+ if_flags |= IFF_PPROMISC;
+ pcap_netmap_ioctl(p, SIOCSIFFLAGS, &if_flags);
+ }
+ }
+ p->linktype = DLT_EN10MB;
+ p->selectable_fd = p->fd;
+ p->read_op = pcap_netmap_dispatch;
+ p->inject_op = pcap_netmap_inject,
+ p->setfilter_op = install_bpf_program;
+ p->setdirection_op = NULL;
+ p->set_datalink_op = NULL;
+ p->getnonblock_op = pcap_getnonblock_fd;
+ p->setnonblock_op = pcap_setnonblock_fd;
+ p->stats_op = pcap_netmap_stats;
+ p->cleanup_op = pcap_netmap_close;
+
+ return (0);
+}
+
+pcap_t *
+pcap_netmap_create(const char *device, char *ebuf, int *is_ours)
+{
+ pcap_t *p;
+
+ *is_ours = (!strncmp(device, "netmap:", 7) || !strncmp(device, "vale", 4));
+ if (! *is_ours)
+ return NULL;
+#ifdef HAVE_NO_PRIV
+ {
+ void *pn = calloc(1, sizeof(struct pcap_netmap));
+ if (pn == NULL)
+ return NULL;
+ p = pcap_create_common(device, ebuf);
+ if (p == NULL) {
+ free(pn);
+ return NULL;
+ }
+ SET_PRIV(p, pn);
+ }
+#else
+ p = pcap_create_common(device, ebuf, sizeof (struct pcap_netmap));
+ if (p == NULL)
+ return (NULL);
+#endif
+ p->activate_op = pcap_netmap_activate;
+ return (p);
+}
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