xref: /freebsd/sys/netpfil/ipfw/ip_fw_bpf.c (revision 577b62c2bacc7dfa228591ca3da361e1bc398301)
1 /*-
2  * Copyright (c) 2016 Yandex LLC
3  * Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
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 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/mbuf.h>
33 #include <sys/kernel.h>
34 #include <sys/lock.h>
35 #include <sys/socket.h>
36 #include <net/ethernet.h>
37 #include <net/if.h>
38 #include <net/if_pflog.h>
39 #include <net/if_var.h>
40 #include <net/if_clone.h>
41 #include <net/if_private.h>
42 #include <net/if_types.h>
43 #include <net/vnet.h>
44 #include <net/bpf.h>
45 
46 #include <netinet/in.h>
47 #include <netinet/ip_fw.h>
48 #include <netinet/ip_var.h>
49 #include <netpfil/ipfw/ip_fw_private.h>
50 
51 VNET_DEFINE_STATIC(struct ifnet *, log_if);
52 VNET_DEFINE_STATIC(struct ifnet *, pflog_if);
53 VNET_DEFINE_STATIC(struct if_clone *, ipfw_cloner);
54 VNET_DEFINE_STATIC(struct if_clone *, ipfwlog_cloner);
55 #define	V_ipfw_cloner		VNET(ipfw_cloner)
56 #define	V_ipfwlog_cloner	VNET(ipfwlog_cloner)
57 #define	V_log_if		VNET(log_if)
58 #define	V_pflog_if		VNET(pflog_if)
59 
60 static const char ipfwname[] = "ipfw";
61 static const char ipfwlogname[] = "ipfwlog";
62 
63 static int
64 ipfw_bpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
65 {
66 
67 	return (EINVAL);
68 }
69 
70 static int
71 ipfw_bpf_output(struct ifnet *ifp, struct mbuf *m,
72 	const struct sockaddr *dst, struct route *ro)
73 {
74 
75 	if (m != NULL)
76 		FREE_PKT(m);
77 	return (0);
78 }
79 
80 static void
81 ipfw_clone_destroy(struct ifnet *ifp)
82 {
83 
84 	if (ifp->if_hdrlen == ETHER_HDR_LEN)
85 		V_log_if = NULL;
86 	else
87 		V_pflog_if = NULL;
88 
89 	NET_EPOCH_WAIT();
90 	bpfdetach(ifp);
91 	if_detach(ifp);
92 	if_free(ifp);
93 }
94 
95 static int
96 ipfw_clone_create(struct if_clone *ifc, int unit, caddr_t params)
97 {
98 	struct ifnet *ifp;
99 
100 	ifp = if_alloc(IFT_PFLOG);
101 	if (ifp == NULL)
102 		return (ENOSPC);
103 	if_initname(ifp, ipfwname, unit);
104 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
105 	ifp->if_mtu = 65536;
106 	ifp->if_ioctl = ipfw_bpf_ioctl;
107 	ifp->if_output = ipfw_bpf_output;
108 	ifp->if_hdrlen = ETHER_HDR_LEN;
109 	if_attach(ifp);
110 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
111 	if (V_log_if != NULL) {
112 		bpfdetach(ifp);
113 		if_detach(ifp);
114 		if_free(ifp);
115 		return (EEXIST);
116 	}
117 	V_log_if = ifp;
118 	return (0);
119 }
120 
121 static int
122 ipfwlog_clone_create(struct if_clone *ifc, int unit, caddr_t params)
123 {
124 	struct ifnet *ifp;
125 
126 	ifp = if_alloc(IFT_PFLOG);
127 	if (ifp == NULL)
128 		return (ENOSPC);
129 	if_initname(ifp, ipfwlogname, unit);
130 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
131 	ifp->if_mtu = 65536;
132 	ifp->if_ioctl = ipfw_bpf_ioctl;
133 	ifp->if_output = ipfw_bpf_output;
134 	ifp->if_hdrlen = PFLOG_HDRLEN;
135 	if_attach(ifp);
136 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
137 	if (V_pflog_if != NULL) {
138 		bpfdetach(ifp);
139 		if_detach(ifp);
140 		if_free(ifp);
141 		return (EEXIST);
142 	}
143 	V_pflog_if = ifp;
144 	return (0);
145 }
146 
147 void
148 ipfw_bpf_tap(u_char *pkt, u_int pktlen)
149 {
150 	struct ifnet *ifp = V_log_if;
151 
152 	NET_EPOCH_ASSERT();
153 	if (ifp != NULL)
154 		BPF_TAP(ifp, pkt, pktlen);
155 }
156 
157 void
158 ipfw_bpf_mtap(struct mbuf *m)
159 {
160 	struct ifnet *ifp = V_log_if;
161 
162 	NET_EPOCH_ASSERT();
163 	if (ifp != NULL)
164 		BPF_MTAP(ifp, m);
165 }
166 
167 void
168 ipfw_bpf_mtap2(void *data, u_int dlen, struct mbuf *m)
169 {
170 	struct ifnet *logif;
171 
172 	NET_EPOCH_ASSERT();
173 	switch (dlen) {
174 	case (ETHER_HDR_LEN):
175 		logif = V_log_if;
176 		break;
177 	case (PFLOG_HDRLEN):
178 		logif = V_pflog_if;
179 		break;
180 	default:
181 #ifdef INVARIANTS
182 		panic("%s: unsupported len %d", __func__, dlen);
183 #endif
184 		logif = NULL;
185 	}
186 
187 	if (logif != NULL)
188 		BPF_MTAP2(logif, data, dlen, m);
189 }
190 
191 void
192 ipfw_bpf_init(int first __unused)
193 {
194 
195 	V_log_if = NULL;
196 	V_pflog_if = NULL;
197 	V_ipfw_cloner = if_clone_simple(ipfwname, ipfw_clone_create,
198 	    ipfw_clone_destroy, 0);
199 	V_ipfwlog_cloner = if_clone_simple(ipfwlogname, ipfwlog_clone_create,
200 	    ipfw_clone_destroy, 0);
201 }
202 
203 void
204 ipfw_bpf_uninit(int last __unused)
205 {
206 
207 	if_clone_detach(V_ipfw_cloner);
208 	if_clone_detach(V_ipfwlog_cloner);
209 }
210