xref: /freebsd/sys/netpfil/ipfw/ip_fw_bpf.c (revision edf8578117e8844e02c0121147f45e4609b30680)
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 #include <sys/param.h>
29 #include <sys/systm.h>
30 #include <sys/mbuf.h>
31 #include <sys/kernel.h>
32 #include <sys/lock.h>
33 #include <sys/socket.h>
34 #include <net/ethernet.h>
35 #include <net/if.h>
36 #include <net/if_pflog.h>
37 #include <net/if_var.h>
38 #include <net/if_clone.h>
39 #include <net/if_private.h>
40 #include <net/if_types.h>
41 #include <net/vnet.h>
42 #include <net/bpf.h>
43 
44 #include <netinet/in.h>
45 #include <netinet/ip_fw.h>
46 #include <netinet/ip_var.h>
47 #include <netpfil/ipfw/ip_fw_private.h>
48 
49 VNET_DEFINE_STATIC(struct ifnet *, log_if);
50 VNET_DEFINE_STATIC(struct ifnet *, pflog_if);
51 VNET_DEFINE_STATIC(struct if_clone *, ipfw_cloner);
52 VNET_DEFINE_STATIC(struct if_clone *, ipfwlog_cloner);
53 #define	V_ipfw_cloner		VNET(ipfw_cloner)
54 #define	V_ipfwlog_cloner	VNET(ipfwlog_cloner)
55 #define	V_log_if		VNET(log_if)
56 #define	V_pflog_if		VNET(pflog_if)
57 
58 static const char ipfwname[] = "ipfw";
59 static const char ipfwlogname[] = "ipfwlog";
60 
61 static int
62 ipfw_bpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
63 {
64 
65 	return (EINVAL);
66 }
67 
68 static int
69 ipfw_bpf_output(struct ifnet *ifp, struct mbuf *m,
70 	const struct sockaddr *dst, struct route *ro)
71 {
72 
73 	if (m != NULL)
74 		FREE_PKT(m);
75 	return (0);
76 }
77 
78 static void
79 ipfw_clone_destroy(struct ifnet *ifp)
80 {
81 
82 	if (ifp->if_hdrlen == ETHER_HDR_LEN)
83 		V_log_if = NULL;
84 	else
85 		V_pflog_if = NULL;
86 
87 	NET_EPOCH_WAIT();
88 	bpfdetach(ifp);
89 	if_detach(ifp);
90 	if_free(ifp);
91 }
92 
93 static int
94 ipfw_clone_create(struct if_clone *ifc, int unit, caddr_t params)
95 {
96 	struct ifnet *ifp;
97 
98 	ifp = if_alloc(IFT_PFLOG);
99 	if (ifp == NULL)
100 		return (ENOSPC);
101 	if_initname(ifp, ipfwname, unit);
102 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
103 	ifp->if_mtu = 65536;
104 	ifp->if_ioctl = ipfw_bpf_ioctl;
105 	ifp->if_output = ipfw_bpf_output;
106 	ifp->if_hdrlen = ETHER_HDR_LEN;
107 	if_attach(ifp);
108 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
109 	if (V_log_if != NULL) {
110 		bpfdetach(ifp);
111 		if_detach(ifp);
112 		if_free(ifp);
113 		return (EEXIST);
114 	}
115 	V_log_if = ifp;
116 	return (0);
117 }
118 
119 static int
120 ipfwlog_clone_create(struct if_clone *ifc, int unit, caddr_t params)
121 {
122 	struct ifnet *ifp;
123 
124 	ifp = if_alloc(IFT_PFLOG);
125 	if (ifp == NULL)
126 		return (ENOSPC);
127 	if_initname(ifp, ipfwlogname, unit);
128 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
129 	ifp->if_mtu = 65536;
130 	ifp->if_ioctl = ipfw_bpf_ioctl;
131 	ifp->if_output = ipfw_bpf_output;
132 	ifp->if_hdrlen = PFLOG_HDRLEN;
133 	if_attach(ifp);
134 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
135 	if (V_pflog_if != NULL) {
136 		bpfdetach(ifp);
137 		if_detach(ifp);
138 		if_free(ifp);
139 		return (EEXIST);
140 	}
141 	V_pflog_if = ifp;
142 	return (0);
143 }
144 
145 void
146 ipfw_bpf_tap(u_char *pkt, u_int pktlen)
147 {
148 	struct ifnet *ifp = V_log_if;
149 
150 	NET_EPOCH_ASSERT();
151 	if (ifp != NULL)
152 		BPF_TAP(ifp, pkt, pktlen);
153 }
154 
155 void
156 ipfw_bpf_mtap(struct mbuf *m)
157 {
158 	struct ifnet *ifp = V_log_if;
159 
160 	NET_EPOCH_ASSERT();
161 	if (ifp != NULL)
162 		BPF_MTAP(ifp, m);
163 }
164 
165 void
166 ipfw_bpf_mtap2(void *data, u_int dlen, struct mbuf *m)
167 {
168 	struct ifnet *logif;
169 
170 	NET_EPOCH_ASSERT();
171 	switch (dlen) {
172 	case (ETHER_HDR_LEN):
173 		logif = V_log_if;
174 		break;
175 	case (PFLOG_HDRLEN):
176 		logif = V_pflog_if;
177 		break;
178 	default:
179 #ifdef INVARIANTS
180 		panic("%s: unsupported len %d", __func__, dlen);
181 #endif
182 		logif = NULL;
183 	}
184 
185 	if (logif != NULL)
186 		BPF_MTAP2(logif, data, dlen, m);
187 }
188 
189 void
190 ipfw_bpf_init(int first __unused)
191 {
192 
193 	V_log_if = NULL;
194 	V_pflog_if = NULL;
195 	V_ipfw_cloner = if_clone_simple(ipfwname, ipfw_clone_create,
196 	    ipfw_clone_destroy, 0);
197 	V_ipfwlog_cloner = if_clone_simple(ipfwlogname, ipfwlog_clone_create,
198 	    ipfw_clone_destroy, 0);
199 }
200 
201 void
202 ipfw_bpf_uninit(int last __unused)
203 {
204 
205 	if_clone_detach(V_ipfw_cloner);
206 	if_clone_detach(V_ipfwlog_cloner);
207 }
208