1 /*- 2 * Copyright (c) 2007 Seccuris Inc. 3 * All rights reserved. 4 * 5 * This software was developed by Robert N. M. Watson under contract to 6 * Seccuris Inc. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * Copyright (c) 1990, 1991, 1993 30 * The Regents of the University of California. All rights reserved. 31 * 32 * This code is derived from the Stanford/CMU enet packet filter, 33 * (net/enet.c) distributed as part of 4.3BSD, and code contributed 34 * to Berkeley by Steven McCanne and Van Jacobson both of Lawrence 35 * Berkeley Laboratory. 36 * 37 * Redistribution and use in source and binary forms, with or without 38 * modification, are permitted provided that the following conditions 39 * are met: 40 * 1. Redistributions of source code must retain the above copyright 41 * notice, this list of conditions and the following disclaimer. 42 * 2. Redistributions in binary form must reproduce the above copyright 43 * notice, this list of conditions and the following disclaimer in the 44 * documentation and/or other materials provided with the distribution. 45 * 4. Neither the name of the University nor the names of its contributors 46 * may be used to endorse or promote products derived from this software 47 * without specific prior written permission. 48 * 49 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 50 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 51 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 52 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 53 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 54 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 55 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 56 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 57 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 58 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 59 * SUCH DAMAGE. 60 * 61 * @(#)bpf.c 8.4 (Berkeley) 1/9/95 62 */ 63 64 #include <sys/cdefs.h> 65 __FBSDID("$FreeBSD$"); 66 67 #include "opt_bpf.h" 68 69 #include <sys/param.h> 70 #include <sys/malloc.h> 71 #include <sys/mbuf.h> 72 #include <sys/socket.h> 73 #include <sys/uio.h> 74 #include <sys/kernel.h> 75 #include <sys/sysctl.h> 76 77 #include <net/if.h> 78 #include <net/bpf.h> 79 #include <net/bpf_buffer.h> 80 #include <net/bpfdesc.h> 81 82 #define PRINET 26 /* interruptible */ 83 84 /* 85 * Implement historical kernel memory buffering model for BPF: two malloc(9) 86 * kernel buffers are hung off of the descriptor. The size is fixed prior to 87 * attaching to an ifnet, ad cannot be changed after that. read(2) simply 88 * copies the data to user space using uiomove(9). 89 */ 90 91 static int bpf_bufsize = 4096; 92 SYSCTL_INT(_net_bpf, OID_AUTO, bufsize, CTLFLAG_RW, 93 &bpf_bufsize, 0, "Default capture buffer size in bytes"); 94 static int bpf_maxbufsize = BPF_MAXBUFSIZE; 95 SYSCTL_INT(_net_bpf, OID_AUTO, maxbufsize, CTLFLAG_RW, 96 &bpf_maxbufsize, 0, "Maximum capture buffer in bytes"); 97 98 /* 99 * Simple data copy to the current kernel buffer. 100 */ 101 void 102 bpf_buffer_append_bytes(struct bpf_d *d, caddr_t buf, u_int offset, 103 void *src, u_int len) 104 { 105 u_char *src_bytes; 106 107 src_bytes = (u_char *)src; 108 bcopy(src_bytes, buf + offset, len); 109 } 110 111 /* 112 * Scatter-gather data copy from an mbuf chain to the current kernel buffer. 113 */ 114 void 115 bpf_buffer_append_mbuf(struct bpf_d *d, caddr_t buf, u_int offset, void *src, 116 u_int len) 117 { 118 const struct mbuf *m; 119 u_char *dst; 120 u_int count; 121 122 m = (struct mbuf *)src; 123 dst = (u_char *)buf + offset; 124 while (len > 0) { 125 if (m == NULL) 126 panic("bpf_mcopy"); 127 count = min(m->m_len, len); 128 bcopy(mtod(m, void *), dst, count); 129 m = m->m_next; 130 dst += count; 131 len -= count; 132 } 133 } 134 135 /* 136 * Free BPF kernel buffers on device close. 137 */ 138 void 139 bpf_buffer_free(struct bpf_d *d) 140 { 141 142 if (d->bd_sbuf != NULL) 143 free(d->bd_sbuf, M_BPF); 144 if (d->bd_hbuf != NULL) 145 free(d->bd_hbuf, M_BPF); 146 if (d->bd_fbuf != NULL) 147 free(d->bd_fbuf, M_BPF); 148 149 #ifdef INVARIANTS 150 d->bd_sbuf = d->bd_hbuf = d->bd_fbuf = (caddr_t)~0; 151 #endif 152 } 153 154 /* 155 * This is a historical initialization that occurs when the BPF descriptor is 156 * first opened. It does not imply selection of a buffer mode, so we don't 157 * allocate buffers here. 158 */ 159 void 160 bpf_buffer_init(struct bpf_d *d) 161 { 162 163 d->bd_bufsize = bpf_bufsize; 164 } 165 166 /* 167 * Allocate or resize buffers. 168 */ 169 int 170 bpf_buffer_ioctl_sblen(struct bpf_d *d, u_int *i) 171 { 172 u_int size; 173 caddr_t fbuf, sbuf; 174 175 size = *i; 176 if (size > bpf_maxbufsize) 177 *i = size = bpf_maxbufsize; 178 else if (size < BPF_MINBUFSIZE) 179 *i = size = BPF_MINBUFSIZE; 180 181 /* Allocate buffers immediately */ 182 fbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK); 183 sbuf = (caddr_t)malloc(size, M_BPF, M_WAITOK); 184 185 BPFD_LOCK(d); 186 if (d->bd_bif != NULL) { 187 /* Interface already attached, unable to change buffers */ 188 BPFD_UNLOCK(d); 189 free(fbuf, M_BPF); 190 free(sbuf, M_BPF); 191 return (EINVAL); 192 } 193 194 while (d->bd_hbuf_in_use) 195 mtx_sleep(&d->bd_hbuf_in_use, &d->bd_lock, 196 PRINET, "bd_hbuf", 0); 197 /* Free old buffers if set */ 198 if (d->bd_fbuf != NULL) 199 free(d->bd_fbuf, M_BPF); 200 if (d->bd_sbuf != NULL) 201 free(d->bd_sbuf, M_BPF); 202 203 /* Fill in new data */ 204 d->bd_bufsize = size; 205 d->bd_fbuf = fbuf; 206 d->bd_sbuf = sbuf; 207 208 d->bd_hbuf = NULL; 209 d->bd_slen = 0; 210 d->bd_hlen = 0; 211 212 BPFD_UNLOCK(d); 213 return (0); 214 } 215 216 /* 217 * Copy buffer storage to user space in read(). 218 */ 219 int 220 bpf_buffer_uiomove(struct bpf_d *d, caddr_t buf, u_int len, struct uio *uio) 221 { 222 223 return (uiomove(buf, len, uio)); 224 } 225