1/*
2 * Copyright (C) 2014 Luigi Rizzo. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 *
8 *   1. Redistributions of source code must retain the above copyright
9 *      notice, this list of conditions and the following disclaimer.
10 *   2. Redistributions in binary form must reproduce the above copyright
11 *      notice, this list of conditions and the following disclaimer in the
12 *      documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifdef HAVE_CONFIG_H
28#include "config.h"
29#endif
30
31#include <poll.h>
32#include <ctype.h>
33#include <errno.h>
34#include <netdb.h>
35#include <stdio.h>
36#include <stdlib.h>
37#include <string.h>
38#include <unistd.h>
39
40#define NETMAP_WITH_LIBS
41#include <net/netmap_user.h>
42
43#include "pcap-int.h"
44
45/*
46 * $FreeBSD$
47 *
48 * This code is meant to build also on other versions of libpcap.
49 *
50 * older libpcap miss p->priv, use p->md.device instead (and allocate).
51 * Also opt.timeout was in md.timeout before.
52 * Use #define PCAP_IF_UP to discriminate
53 */
54#ifdef PCAP_IF_UP
55#define NM_PRIV(p)	((struct pcap_netmap *)(p->priv))
56#define the_timeout	opt.timeout
57#else
58#define HAVE_NO_PRIV
59#define	NM_PRIV(p)	((struct pcap_netmap *)(p->md.device))
60#define SET_PRIV(p, x)	p->md.device = (void *)x
61#define the_timeout	md.timeout
62#endif
63
64#if defined (linux)
65/* On FreeBSD we use IFF_PPROMISC which is in ifr_flagshigh.
66 * remap to IFF_PROMISC on linux
67 */
68#define IFF_PPROMISC	IFF_PROMISC
69#endif /* linux */
70
71struct pcap_netmap {
72	struct nm_desc *d;	/* pointer returned by nm_open() */
73	pcap_handler cb;	/* callback and argument */
74	u_char *cb_arg;
75	int must_clear_promisc;	/* flag */
76	uint64_t rx_pkts;	/* # of pkts received before the filter */
77};
78
79
80static int
81pcap_netmap_stats(pcap_t *p, struct pcap_stat *ps)
82{
83	struct pcap_netmap *pn = NM_PRIV(p);
84
85	ps->ps_recv = pn->rx_pkts;
86	ps->ps_drop = 0;
87	ps->ps_ifdrop = 0;
88	return 0;
89}
90
91
92static void
93pcap_netmap_filter(u_char *arg, struct pcap_pkthdr *h, const u_char *buf)
94{
95	pcap_t *p = (pcap_t *)arg;
96	struct pcap_netmap *pn = NM_PRIV(p);
97	const struct bpf_insn *pc = p->fcode.bf_insns;
98
99	++pn->rx_pkts;
100	if (pc == NULL || bpf_filter(pc, buf, h->len, h->caplen))
101		pn->cb(pn->cb_arg, h, buf);
102}
103
104
105static int
106pcap_netmap_dispatch(pcap_t *p, int cnt, pcap_handler cb, u_char *user)
107{
108	int ret;
109	struct pcap_netmap *pn = NM_PRIV(p);
110	struct nm_desc *d = pn->d;
111	struct pollfd pfd = { .fd = p->fd, .events = POLLIN, .revents = 0 };
112
113	pn->cb = cb;
114	pn->cb_arg = user;
115
116	for (;;) {
117		if (p->break_loop) {
118			p->break_loop = 0;
119			return PCAP_ERROR_BREAK;
120		}
121		/* nm_dispatch won't run forever */
122
123		ret = nm_dispatch((void *)d, cnt, (void *)pcap_netmap_filter, (void *)p);
124		if (ret != 0)
125			break;
126		errno = 0;
127		ret = poll(&pfd, 1, p->the_timeout);
128	}
129	return ret;
130}
131
132
133/* XXX need to check the NIOCTXSYNC/poll */
134static int
135pcap_netmap_inject(pcap_t *p, const void *buf, size_t size)
136{
137	struct nm_desc *d = NM_PRIV(p)->d;
138
139	return nm_inject(d, buf, size);
140}
141
142
143static int
144pcap_netmap_ioctl(pcap_t *p, u_long what, uint32_t *if_flags)
145{
146	struct pcap_netmap *pn = NM_PRIV(p);
147	struct nm_desc *d = pn->d;
148	struct ifreq ifr;
149	int error, fd = d->fd;
150
151#ifdef linux
152	fd = socket(AF_INET, SOCK_DGRAM, 0);
153	if (fd < 0) {
154		fprintf(stderr, "Error: cannot get device control socket.\n");
155		return -1;
156	}
157#endif /* linux */
158	bzero(&ifr, sizeof(ifr));
159	strncpy(ifr.ifr_name, d->req.nr_name, sizeof(ifr.ifr_name));
160	switch (what) {
161	case SIOCSIFFLAGS:
162		ifr.ifr_flags = *if_flags;
163#ifdef __FreeBSD__
164		ifr.ifr_flagshigh = *if_flags >> 16;
165#endif /* __FreeBSD__ */
166		break;
167	}
168	error = ioctl(fd, what, &ifr);
169	if (!error) {
170		switch (what) {
171		case SIOCGIFFLAGS:
172			*if_flags = ifr.ifr_flags;
173#ifdef __FreeBSD__
174			*if_flags |= (ifr.ifr_flagshigh << 16);
175#endif /* __FreeBSD__ */
176		}
177	}
178#ifdef linux
179	close(fd);
180#endif /* linux */
181	return error ? -1 : 0;
182}
183
184
185static void
186pcap_netmap_close(pcap_t *p)
187{
188	struct pcap_netmap *pn = NM_PRIV(p);
189	struct nm_desc *d = pn->d;
190	uint32_t if_flags = 0;
191
192	if (pn->must_clear_promisc) {
193		pcap_netmap_ioctl(p, SIOCGIFFLAGS, &if_flags); /* fetch flags */
194		if (if_flags & IFF_PPROMISC) {
195			if_flags &= ~IFF_PPROMISC;
196			pcap_netmap_ioctl(p, SIOCSIFFLAGS, &if_flags);
197		}
198	}
199	nm_close(d);
200#ifdef HAVE_NO_PRIV
201	free(pn);
202	SET_PRIV(p, NULL); // unnecessary
203#endif
204	pcap_cleanup_live_common(p);
205}
206
207
208static int
209pcap_netmap_activate(pcap_t *p)
210{
211	struct pcap_netmap *pn = NM_PRIV(p);
212	struct nm_desc *d = nm_open(p->opt.source, NULL, 0, NULL);
213	uint32_t if_flags = 0;
214
215	if (d == NULL) {
216		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
217			"netmap open: cannot access %s: %s\n",
218			p->opt.source, pcap_strerror(errno));
219#ifdef HAVE_NO_PRIV
220		free(pn);
221		SET_PRIV(p, NULL); // unnecessary
222#endif
223		pcap_cleanup_live_common(p);
224		return (PCAP_ERROR);
225	}
226	if (0)
227	    fprintf(stderr, "%s device %s priv %p fd %d ports %d..%d\n",
228		__FUNCTION__, p->opt.source, d, d->fd,
229		d->first_rx_ring, d->last_rx_ring);
230	pn->d = d;
231	p->fd = d->fd;
232	if (p->opt.promisc && !(d->req.nr_ringid & NETMAP_SW_RING)) {
233		pcap_netmap_ioctl(p, SIOCGIFFLAGS, &if_flags); /* fetch flags */
234		if (!(if_flags & IFF_PPROMISC)) {
235			pn->must_clear_promisc = 1;
236			if_flags |= IFF_PPROMISC;
237			pcap_netmap_ioctl(p, SIOCSIFFLAGS, &if_flags);
238		}
239	}
240	p->linktype = DLT_EN10MB;
241	p->selectable_fd = p->fd;
242	p->read_op = pcap_netmap_dispatch;
243	p->inject_op = pcap_netmap_inject;
244	p->setfilter_op = install_bpf_program;
245	p->setdirection_op = NULL;
246	p->set_datalink_op = NULL;
247	p->getnonblock_op = pcap_getnonblock_fd;
248	p->setnonblock_op = pcap_setnonblock_fd;
249	p->stats_op = pcap_netmap_stats;
250	p->cleanup_op = pcap_netmap_close;
251
252	return (0);
253}
254
255
256pcap_t *
257pcap_netmap_create(const char *device, char *ebuf, int *is_ours)
258{
259	pcap_t *p;
260
261	*is_ours = (!strncmp(device, "netmap:", 7) || !strncmp(device, "vale", 4));
262	if (! *is_ours)
263		return NULL;
264#ifdef HAVE_NO_PRIV
265	{
266		void *pn = calloc(1, sizeof(struct pcap_netmap));
267		if (pn == NULL)
268			return NULL;
269		p = pcap_create_common(device, ebuf);
270		if (p == NULL) {
271			free(pn);
272			return NULL;
273		}
274		SET_PRIV(p, pn);
275	}
276#else
277	p = pcap_create_common(device, ebuf, sizeof (struct pcap_netmap));
278	if (p == NULL)
279		return (NULL);
280#endif
281	p->activate_op = pcap_netmap_activate;
282	return (p);
283}
284