xref: /freebsd/sys/netpfil/ipfw/ip_fw_bpf.c (revision 1631382cf2820245cc72965498ff174bb548dd63)
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/param.h>
28 #include <sys/systm.h>
29 #include <sys/mbuf.h>
30 #include <sys/kernel.h>
31 #include <sys/lock.h>
32 #include <sys/socket.h>
33 #include <net/ethernet.h>
34 #include <net/if.h>
35 #include <net/if_pflog.h>
36 #include <net/if_var.h>
37 #include <net/if_clone.h>
38 #include <net/if_private.h>
39 #include <net/if_types.h>
40 #include <net/vnet.h>
41 #include <net/bpf.h>
42 
43 #include <netinet/in.h>
44 #include <netinet/ip_fw.h>
45 #include <netinet/ip_var.h>
46 #include <netpfil/ipfw/ip_fw_private.h>
47 
48 VNET_DEFINE_STATIC(struct ifnet *, log_if);
49 VNET_DEFINE_STATIC(struct ifnet *, pflog_if);
50 VNET_DEFINE_STATIC(struct if_clone *, ipfw_cloner);
51 VNET_DEFINE_STATIC(struct if_clone *, ipfwlog_cloner);
52 #define	V_ipfw_cloner		VNET(ipfw_cloner)
53 #define	V_ipfwlog_cloner	VNET(ipfwlog_cloner)
54 #define	V_log_if		VNET(log_if)
55 #define	V_pflog_if		VNET(pflog_if)
56 
57 static const char ipfwname[] = "ipfw";
58 static const char ipfwlogname[] = "ipfwlog";
59 
60 static int
61 ipfw_bpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
62 {
63 
64 	return (EINVAL);
65 }
66 
67 static int
68 ipfw_bpf_output(struct ifnet *ifp, struct mbuf *m,
69 	const struct sockaddr *dst, struct route *ro)
70 {
71 
72 	if (m != NULL)
73 		FREE_PKT(m);
74 	return (0);
75 }
76 
77 static void
78 ipfw_clone_destroy(struct ifnet *ifp)
79 {
80 
81 	if (ifp->if_hdrlen == ETHER_HDR_LEN)
82 		V_log_if = NULL;
83 	else
84 		V_pflog_if = NULL;
85 
86 	NET_EPOCH_WAIT();
87 	bpfdetach(ifp);
88 	if_detach(ifp);
89 	if_free(ifp);
90 }
91 
92 static int
93 ipfw_clone_create(struct if_clone *ifc, int unit, caddr_t params)
94 {
95 	struct ifnet *ifp;
96 
97 	ifp = if_alloc(IFT_PFLOG);
98 	if (ifp == NULL)
99 		return (ENOSPC);
100 	if_initname(ifp, ipfwname, unit);
101 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
102 	ifp->if_mtu = 65536;
103 	ifp->if_ioctl = ipfw_bpf_ioctl;
104 	ifp->if_output = ipfw_bpf_output;
105 	ifp->if_hdrlen = ETHER_HDR_LEN;
106 	if_attach(ifp);
107 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
108 	if (V_log_if != NULL) {
109 		bpfdetach(ifp);
110 		if_detach(ifp);
111 		if_free(ifp);
112 		return (EEXIST);
113 	}
114 	V_log_if = ifp;
115 	return (0);
116 }
117 
118 static int
119 ipfwlog_clone_create(struct if_clone *ifc, int unit, caddr_t params)
120 {
121 	struct ifnet *ifp;
122 
123 	ifp = if_alloc(IFT_PFLOG);
124 	if (ifp == NULL)
125 		return (ENOSPC);
126 	if_initname(ifp, ipfwlogname, unit);
127 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
128 	ifp->if_mtu = 65536;
129 	ifp->if_ioctl = ipfw_bpf_ioctl;
130 	ifp->if_output = ipfw_bpf_output;
131 	ifp->if_hdrlen = PFLOG_HDRLEN;
132 	if_attach(ifp);
133 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
134 	if (V_pflog_if != NULL) {
135 		bpfdetach(ifp);
136 		if_detach(ifp);
137 		if_free(ifp);
138 		return (EEXIST);
139 	}
140 	V_pflog_if = ifp;
141 	return (0);
142 }
143 
144 void
145 ipfw_bpf_tap(u_char *pkt, u_int pktlen)
146 {
147 	struct ifnet *ifp = V_log_if;
148 
149 	NET_EPOCH_ASSERT();
150 	if (ifp != NULL)
151 		BPF_TAP(ifp, pkt, pktlen);
152 }
153 
154 void
155 ipfw_bpf_mtap(struct mbuf *m)
156 {
157 	struct ifnet *ifp = V_log_if;
158 
159 	NET_EPOCH_ASSERT();
160 	if (ifp != NULL)
161 		BPF_MTAP(ifp, m);
162 }
163 
164 void
165 ipfw_bpf_mtap2(void *data, u_int dlen, struct mbuf *m)
166 {
167 	struct ifnet *logif;
168 
169 	NET_EPOCH_ASSERT();
170 	switch (dlen) {
171 	case (ETHER_HDR_LEN):
172 		logif = V_log_if;
173 		break;
174 	case (PFLOG_HDRLEN):
175 		logif = V_pflog_if;
176 		break;
177 	default:
178 #ifdef INVARIANTS
179 		panic("%s: unsupported len %d", __func__, dlen);
180 #endif
181 		logif = NULL;
182 	}
183 
184 	if (logif != NULL)
185 		BPF_MTAP2(logif, data, dlen, m);
186 }
187 
188 void
189 ipfw_bpf_init(int first __unused)
190 {
191 
192 	V_log_if = NULL;
193 	V_pflog_if = NULL;
194 	V_ipfw_cloner = if_clone_simple(ipfwname, ipfw_clone_create,
195 	    ipfw_clone_destroy, 0);
196 	V_ipfwlog_cloner = if_clone_simple(ipfwlogname, ipfwlog_clone_create,
197 	    ipfw_clone_destroy, 0);
198 }
199 
200 void
201 ipfw_bpf_uninit(int last __unused)
202 {
203 
204 	if_clone_detach(V_ipfw_cloner);
205 	if_clone_detach(V_ipfwlog_cloner);
206 }
207