xref: /freebsd/sys/netpfil/ipfw/ip_fw_bpf.c (revision 0957b409a90fd597c1e9124cbaf3edd2b488f4ac)
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/rmlock.h>
36 #include <sys/socket.h>
37 #include <net/ethernet.h>
38 #include <net/if.h>
39 #include <net/if_pflog.h>
40 #include <net/if_var.h>
41 #include <net/if_clone.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 struct rmlock log_if_lock;
61 #define	LOGIF_LOCK_INIT(x)	rm_init(&log_if_lock, "ipfw log_if lock")
62 #define	LOGIF_LOCK_DESTROY(x)	rm_destroy(&log_if_lock)
63 #define	LOGIF_RLOCK_TRACKER	struct rm_priotracker _log_tracker
64 #define	LOGIF_RLOCK(x)		rm_rlock(&log_if_lock, &_log_tracker)
65 #define	LOGIF_RUNLOCK(x)	rm_runlock(&log_if_lock, &_log_tracker)
66 #define	LOGIF_WLOCK(x)		rm_wlock(&log_if_lock)
67 #define	LOGIF_WUNLOCK(x)	rm_wunlock(&log_if_lock)
68 
69 static const char ipfwname[] = "ipfw";
70 static const char ipfwlogname[] = "ipfwlog";
71 
72 static int
73 ipfw_bpf_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr)
74 {
75 
76 	return (EINVAL);
77 }
78 
79 static int
80 ipfw_bpf_output(struct ifnet *ifp, struct mbuf *m,
81 	const struct sockaddr *dst, struct route *ro)
82 {
83 
84 	if (m != NULL)
85 		FREE_PKT(m);
86 	return (0);
87 }
88 
89 static void
90 ipfw_clone_destroy(struct ifnet *ifp)
91 {
92 
93 	LOGIF_WLOCK();
94 	if (ifp->if_hdrlen == ETHER_HDR_LEN)
95 		V_log_if = NULL;
96 	else
97 		V_pflog_if = NULL;
98 	LOGIF_WUNLOCK();
99 
100 	bpfdetach(ifp);
101 	if_detach(ifp);
102 	if_free(ifp);
103 }
104 
105 static int
106 ipfw_clone_create(struct if_clone *ifc, int unit, caddr_t params)
107 {
108 	struct ifnet *ifp;
109 
110 	ifp = if_alloc(IFT_PFLOG);
111 	if (ifp == NULL)
112 		return (ENOSPC);
113 	if_initname(ifp, ipfwname, unit);
114 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
115 	ifp->if_mtu = 65536;
116 	ifp->if_ioctl = ipfw_bpf_ioctl;
117 	ifp->if_output = ipfw_bpf_output;
118 	ifp->if_hdrlen = ETHER_HDR_LEN;
119 	if_attach(ifp);
120 	bpfattach(ifp, DLT_EN10MB, ETHER_HDR_LEN);
121 	LOGIF_WLOCK();
122 	if (V_log_if != NULL) {
123 		LOGIF_WUNLOCK();
124 		bpfdetach(ifp);
125 		if_detach(ifp);
126 		if_free(ifp);
127 		return (EEXIST);
128 	}
129 	V_log_if = ifp;
130 	LOGIF_WUNLOCK();
131 	return (0);
132 }
133 
134 static int
135 ipfwlog_clone_create(struct if_clone *ifc, int unit, caddr_t params)
136 {
137 	struct ifnet *ifp;
138 
139 	ifp = if_alloc(IFT_PFLOG);
140 	if (ifp == NULL)
141 		return (ENOSPC);
142 	if_initname(ifp, ipfwlogname, unit);
143 	ifp->if_flags = IFF_UP | IFF_SIMPLEX | IFF_MULTICAST;
144 	ifp->if_mtu = 65536;
145 	ifp->if_ioctl = ipfw_bpf_ioctl;
146 	ifp->if_output = ipfw_bpf_output;
147 	ifp->if_hdrlen = PFLOG_HDRLEN;
148 	if_attach(ifp);
149 	bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN);
150 	LOGIF_WLOCK();
151 	if (V_pflog_if != NULL) {
152 		LOGIF_WUNLOCK();
153 		bpfdetach(ifp);
154 		if_detach(ifp);
155 		if_free(ifp);
156 		return (EEXIST);
157 	}
158 	V_pflog_if = ifp;
159 	LOGIF_WUNLOCK();
160 	return (0);
161 }
162 
163 void
164 ipfw_bpf_mtap2(void *data, u_int dlen, struct mbuf *m)
165 {
166 	LOGIF_RLOCK_TRACKER;
167 
168 	LOGIF_RLOCK();
169 	if (dlen == ETHER_HDR_LEN) {
170 		if (V_log_if == NULL) {
171 			LOGIF_RUNLOCK();
172 			return;
173 		}
174 		BPF_MTAP2(V_log_if, data, dlen, m);
175 	} else if (dlen == PFLOG_HDRLEN) {
176 		if (V_pflog_if == NULL) {
177 			LOGIF_RUNLOCK();
178 			return;
179 		}
180 		BPF_MTAP2(V_pflog_if, data, dlen, m);
181 	}
182 	LOGIF_RUNLOCK();
183 }
184 
185 void
186 ipfw_bpf_init(int first)
187 {
188 
189 	if (first) {
190 		LOGIF_LOCK_INIT();
191 		V_log_if = NULL;
192 		V_pflog_if = NULL;
193 	}
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)
202 {
203 
204 	if_clone_detach(V_ipfw_cloner);
205 	if_clone_detach(V_ipfwlog_cloner);
206 	if (last)
207 		LOGIF_LOCK_DESTROY();
208 }
209 
210