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: stable/10/lib/libpcap/pcap-netmap.c 305619 2016-09-08 15:27:42Z pfg $
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
71 struct 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
80 static int
pcap_netmap_stats(pcap_t * p,struct pcap_stat * ps)81 pcap_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
92 static void
pcap_netmap_filter(u_char * arg,struct pcap_pkthdr * h,const u_char * buf)93 pcap_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
105 static int
pcap_netmap_dispatch(pcap_t * p,int cnt,pcap_handler cb,u_char * user)106 pcap_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 */
134 static int
pcap_netmap_inject(pcap_t * p,const void * buf,size_t size)135 pcap_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
143 static int
pcap_netmap_ioctl(pcap_t * p,u_long what,uint32_t * if_flags)144 pcap_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
185 static void
pcap_netmap_close(pcap_t * p)186 pcap_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
208 static int
pcap_netmap_activate(pcap_t * p)209 pcap_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
256 pcap_t *
pcap_netmap_create(const char * device,char * ebuf,int * is_ours)257 pcap_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