xref: /freebsd/sys/netpfil/ipfw/ip_fw_bpf.c (revision cc68614da8232d8baaca0ae0d0dd8f890f06623e)
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_types.h>
42 #include <net/vnet.h>
43 #include <net/bpf.h>
44 
45 #include <netinet/in.h>
46 #include <netinet/ip_fw.h>
47 #include <netinet/ip_var.h>
48 #include <netpfil/ipfw/ip_fw_private.h>
49 
50 VNET_DEFINE_STATIC(struct ifnet *, log_if);
51 VNET_DEFINE_STATIC(struct ifnet *, pflog_if);
52 VNET_DEFINE_STATIC(struct if_clone *, ipfw_cloner);
53 VNET_DEFINE_STATIC(struct if_clone *, ipfwlog_cloner);
54 #define	V_ipfw_cloner		VNET(ipfw_cloner)
55 #define	V_ipfwlog_cloner	VNET(ipfwlog_cloner)
56 #define	V_log_if		VNET(log_if)
57 #define	V_pflog_if		VNET(pflog_if)
58 
59 static const char ipfwname[] = "ipfw";
60 static const char ipfwlogname[] = "ipfwlog";
61 
62 static int
63 ipfw_bpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
64 {
65 
66 	return (EINVAL);
67 }
68 
69 static int
70 ipfw_bpf_output(struct ifnet *ifp, struct mbuf *m,
71 	const struct sockaddr *dst, struct route *ro)
72 {
73 
74 	if (m != NULL)
75 		FREE_PKT(m);
76 	return (0);
77 }
78 
79 static void
80 ipfw_clone_destroy(struct ifnet *ifp)
81 {
82 
83 	if (ifp->if_hdrlen == ETHER_HDR_LEN)
84 		V_log_if = NULL;
85 	else
86 		V_pflog_if = NULL;
87 
88 	NET_EPOCH_WAIT();
89 	bpfdetach(ifp);
90 	if_detach(ifp);
91 	if_free(ifp);
92 }
93 
94 static int
95 ipfw_clone_create(struct if_clone *ifc, int unit, caddr_t params)
96 {
97 	struct ifnet *ifp;
98 
99 	ifp = if_alloc(IFT_PFLOG);
100 	if (ifp == NULL)
101 		return (ENOSPC);
102 	if_initname(ifp, ipfwname, unit);
103 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
104 	ifp->if_mtu = 65536;
105 	ifp->if_ioctl = ipfw_bpf_ioctl;
106 	ifp->if_output = ipfw_bpf_output;
107 	ifp->if_hdrlen = ETHER_HDR_LEN;
108 	if_attach(ifp);
109 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
110 	if (V_log_if != NULL) {
111 		bpfdetach(ifp);
112 		if_detach(ifp);
113 		if_free(ifp);
114 		return (EEXIST);
115 	}
116 	V_log_if = ifp;
117 	return (0);
118 }
119 
120 static int
121 ipfwlog_clone_create(struct if_clone *ifc, int unit, caddr_t params)
122 {
123 	struct ifnet *ifp;
124 
125 	ifp = if_alloc(IFT_PFLOG);
126 	if (ifp == NULL)
127 		return (ENOSPC);
128 	if_initname(ifp, ipfwlogname, unit);
129 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
130 	ifp->if_mtu = 65536;
131 	ifp->if_ioctl = ipfw_bpf_ioctl;
132 	ifp->if_output = ipfw_bpf_output;
133 	ifp->if_hdrlen = PFLOG_HDRLEN;
134 	if_attach(ifp);
135 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
136 	if (V_pflog_if != NULL) {
137 		bpfdetach(ifp);
138 		if_detach(ifp);
139 		if_free(ifp);
140 		return (EEXIST);
141 	}
142 	V_pflog_if = ifp;
143 	return (0);
144 }
145 
146 void
147 ipfw_bpf_tap(u_char *pkt, u_int pktlen)
148 {
149 	struct ifnet *ifp = V_log_if;
150 
151 	NET_EPOCH_ASSERT();
152 	if (ifp != NULL)
153 		BPF_TAP(ifp, pkt, pktlen);
154 }
155 
156 void
157 ipfw_bpf_mtap(struct mbuf *m)
158 {
159 	struct ifnet *ifp = V_log_if;
160 
161 	NET_EPOCH_ASSERT();
162 	if (ifp != NULL)
163 		BPF_MTAP(ifp, m);
164 }
165 
166 void
167 ipfw_bpf_mtap2(void *data, u_int dlen, struct mbuf *m)
168 {
169 	struct ifnet *logif;
170 
171 	NET_EPOCH_ASSERT();
172 	switch (dlen) {
173 	case (ETHER_HDR_LEN):
174 		logif = V_log_if;
175 		break;
176 	case (PFLOG_HDRLEN):
177 		logif = V_pflog_if;
178 		break;
179 	default:
180 #ifdef INVARIANTS
181 		panic("%s: unsupported len %d", __func__, dlen);
182 #endif
183 		logif = NULL;
184 	}
185 
186 	if (logif != NULL)
187 		BPF_MTAP2(logif, data, dlen, m);
188 }
189 
190 void
191 ipfw_bpf_init(int first __unused)
192 {
193 
194 	V_log_if = NULL;
195 	V_pflog_if = NULL;
196 	V_ipfw_cloner = if_clone_simple(ipfwname, ipfw_clone_create,
197 	    ipfw_clone_destroy, 0);
198 	V_ipfwlog_cloner = if_clone_simple(ipfwlogname, ipfwlog_clone_create,
199 	    ipfw_clone_destroy, 0);
200 }
201 
202 void
203 ipfw_bpf_uninit(int last __unused)
204 {
205 
206 	if_clone_detach(V_ipfw_cloner);
207 	if_clone_detach(V_ipfwlog_cloner);
208 }
209