Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 1 | /* |
| 2 | * common LSM auditing functions |
| 3 | * |
| 4 | * Based on code written for SELinux by : |
| 5 | * Stephen Smalley, <sds@epoch.ncsc.mil> |
| 6 | * James Morris <jmorris@redhat.com> |
| 7 | * Author : Etienne Basset, <etienne.basset@ensta.org> |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License version 2, |
| 11 | * as published by the Free Software Foundation. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/types.h> |
| 15 | #include <linux/stddef.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/fs.h> |
| 18 | #include <linux/init.h> |
| 19 | #include <net/sock.h> |
| 20 | #include <linux/un.h> |
| 21 | #include <net/af_unix.h> |
| 22 | #include <linux/audit.h> |
| 23 | #include <linux/ipv6.h> |
| 24 | #include <linux/ip.h> |
| 25 | #include <net/ip.h> |
| 26 | #include <net/ipv6.h> |
| 27 | #include <linux/tcp.h> |
| 28 | #include <linux/udp.h> |
| 29 | #include <linux/dccp.h> |
| 30 | #include <linux/sctp.h> |
| 31 | #include <linux/lsm_audit.h> |
| 32 | |
| 33 | /** |
| 34 | * ipv4_skb_to_auditdata : fill auditdata from skb |
| 35 | * @skb : the skb |
| 36 | * @ad : the audit data to fill |
| 37 | * @proto : the layer 4 protocol |
| 38 | * |
| 39 | * return 0 on success |
| 40 | */ |
| 41 | int ipv4_skb_to_auditdata(struct sk_buff *skb, |
| 42 | struct common_audit_data *ad, u8 *proto) |
| 43 | { |
| 44 | int ret = 0; |
| 45 | struct iphdr *ih; |
| 46 | |
| 47 | ih = ip_hdr(skb); |
| 48 | if (ih == NULL) |
| 49 | return -EINVAL; |
| 50 | |
| 51 | ad->u.net.v4info.saddr = ih->saddr; |
| 52 | ad->u.net.v4info.daddr = ih->daddr; |
| 53 | |
| 54 | if (proto) |
| 55 | *proto = ih->protocol; |
| 56 | /* non initial fragment */ |
| 57 | if (ntohs(ih->frag_off) & IP_OFFSET) |
| 58 | return 0; |
| 59 | |
| 60 | switch (ih->protocol) { |
| 61 | case IPPROTO_TCP: { |
| 62 | struct tcphdr *th = tcp_hdr(skb); |
| 63 | if (th == NULL) |
| 64 | break; |
| 65 | |
| 66 | ad->u.net.sport = th->source; |
| 67 | ad->u.net.dport = th->dest; |
| 68 | break; |
| 69 | } |
| 70 | case IPPROTO_UDP: { |
| 71 | struct udphdr *uh = udp_hdr(skb); |
| 72 | if (uh == NULL) |
| 73 | break; |
| 74 | |
| 75 | ad->u.net.sport = uh->source; |
| 76 | ad->u.net.dport = uh->dest; |
| 77 | break; |
| 78 | } |
| 79 | case IPPROTO_DCCP: { |
| 80 | struct dccp_hdr *dh = dccp_hdr(skb); |
| 81 | if (dh == NULL) |
| 82 | break; |
| 83 | |
| 84 | ad->u.net.sport = dh->dccph_sport; |
| 85 | ad->u.net.dport = dh->dccph_dport; |
| 86 | break; |
| 87 | } |
| 88 | case IPPROTO_SCTP: { |
| 89 | struct sctphdr *sh = sctp_hdr(skb); |
| 90 | if (sh == NULL) |
| 91 | break; |
| 92 | ad->u.net.sport = sh->source; |
| 93 | ad->u.net.dport = sh->dest; |
| 94 | break; |
| 95 | } |
| 96 | default: |
| 97 | ret = -EINVAL; |
| 98 | } |
| 99 | return ret; |
| 100 | } |
| 101 | #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) |
| 102 | /** |
| 103 | * ipv6_skb_to_auditdata : fill auditdata from skb |
| 104 | * @skb : the skb |
| 105 | * @ad : the audit data to fill |
| 106 | * @proto : the layer 4 protocol |
| 107 | * |
| 108 | * return 0 on success |
| 109 | */ |
| 110 | int ipv6_skb_to_auditdata(struct sk_buff *skb, |
| 111 | struct common_audit_data *ad, u8 *proto) |
| 112 | { |
| 113 | int offset, ret = 0; |
| 114 | struct ipv6hdr *ip6; |
| 115 | u8 nexthdr; |
| 116 | |
| 117 | ip6 = ipv6_hdr(skb); |
| 118 | if (ip6 == NULL) |
| 119 | return -EINVAL; |
| 120 | ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr); |
| 121 | ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr); |
| 122 | ret = 0; |
| 123 | /* IPv6 can have several extension header before the Transport header |
| 124 | * skip them */ |
| 125 | offset = skb_network_offset(skb); |
| 126 | offset += sizeof(*ip6); |
| 127 | nexthdr = ip6->nexthdr; |
| 128 | offset = ipv6_skip_exthdr(skb, offset, &nexthdr); |
| 129 | if (offset < 0) |
| 130 | return 0; |
| 131 | if (proto) |
| 132 | *proto = nexthdr; |
| 133 | switch (nexthdr) { |
| 134 | case IPPROTO_TCP: { |
| 135 | struct tcphdr _tcph, *th; |
| 136 | |
| 137 | th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); |
| 138 | if (th == NULL) |
| 139 | break; |
| 140 | |
| 141 | ad->u.net.sport = th->source; |
| 142 | ad->u.net.dport = th->dest; |
| 143 | break; |
| 144 | } |
| 145 | case IPPROTO_UDP: { |
| 146 | struct udphdr _udph, *uh; |
| 147 | |
| 148 | uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); |
| 149 | if (uh == NULL) |
| 150 | break; |
| 151 | |
| 152 | ad->u.net.sport = uh->source; |
| 153 | ad->u.net.dport = uh->dest; |
| 154 | break; |
| 155 | } |
| 156 | case IPPROTO_DCCP: { |
| 157 | struct dccp_hdr _dccph, *dh; |
| 158 | |
| 159 | dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); |
| 160 | if (dh == NULL) |
| 161 | break; |
| 162 | |
| 163 | ad->u.net.sport = dh->dccph_sport; |
| 164 | ad->u.net.dport = dh->dccph_dport; |
| 165 | break; |
| 166 | } |
| 167 | case IPPROTO_SCTP: { |
| 168 | struct sctphdr _sctph, *sh; |
| 169 | |
| 170 | sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); |
| 171 | if (sh == NULL) |
| 172 | break; |
| 173 | ad->u.net.sport = sh->source; |
| 174 | ad->u.net.dport = sh->dest; |
| 175 | break; |
| 176 | } |
| 177 | default: |
| 178 | ret = -EINVAL; |
| 179 | } |
| 180 | return ret; |
| 181 | } |
| 182 | #endif |
| 183 | |
| 184 | |
| 185 | static inline void print_ipv6_addr(struct audit_buffer *ab, |
| 186 | struct in6_addr *addr, __be16 port, |
| 187 | char *name1, char *name2) |
| 188 | { |
| 189 | if (!ipv6_addr_any(addr)) |
Paul Moore | d811659 | 2009-09-23 13:46:00 -0400 | [diff] [blame] | 190 | audit_log_format(ab, " %s=%pI6c", name1, addr); |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 191 | if (port) |
| 192 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| 193 | } |
| 194 | |
| 195 | static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, |
| 196 | __be16 port, char *name1, char *name2) |
| 197 | { |
| 198 | if (addr) |
| 199 | audit_log_format(ab, " %s=%pI4", name1, &addr); |
| 200 | if (port) |
| 201 | audit_log_format(ab, " %s=%d", name2, ntohs(port)); |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * dump_common_audit_data - helper to dump common audit data |
| 206 | * @a : common audit data |
| 207 | * |
| 208 | */ |
| 209 | static void dump_common_audit_data(struct audit_buffer *ab, |
| 210 | struct common_audit_data *a) |
| 211 | { |
| 212 | struct inode *inode = NULL; |
| 213 | struct task_struct *tsk = current; |
| 214 | |
| 215 | if (a->tsk) |
| 216 | tsk = a->tsk; |
| 217 | if (tsk && tsk->pid) { |
| 218 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
| 219 | audit_log_untrustedstring(ab, tsk->comm); |
| 220 | } |
| 221 | |
| 222 | switch (a->type) { |
Thomas Liu | 2bf4969 | 2009-07-14 12:14:09 -0400 | [diff] [blame] | 223 | case LSM_AUDIT_NO_AUDIT: |
| 224 | return; |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 225 | case LSM_AUDIT_DATA_IPC: |
| 226 | audit_log_format(ab, " key=%d ", a->u.ipc_id); |
| 227 | break; |
| 228 | case LSM_AUDIT_DATA_CAP: |
| 229 | audit_log_format(ab, " capability=%d ", a->u.cap); |
| 230 | break; |
| 231 | case LSM_AUDIT_DATA_FS: |
| 232 | if (a->u.fs.path.dentry) { |
| 233 | struct dentry *dentry = a->u.fs.path.dentry; |
| 234 | if (a->u.fs.path.mnt) { |
| 235 | audit_log_d_path(ab, "path=", &a->u.fs.path); |
| 236 | } else { |
| 237 | audit_log_format(ab, " name="); |
| 238 | audit_log_untrustedstring(ab, |
| 239 | dentry->d_name.name); |
| 240 | } |
| 241 | inode = dentry->d_inode; |
| 242 | } else if (a->u.fs.inode) { |
| 243 | struct dentry *dentry; |
| 244 | inode = a->u.fs.inode; |
| 245 | dentry = d_find_alias(inode); |
| 246 | if (dentry) { |
| 247 | audit_log_format(ab, " name="); |
| 248 | audit_log_untrustedstring(ab, |
| 249 | dentry->d_name.name); |
| 250 | dput(dentry); |
| 251 | } |
| 252 | } |
| 253 | if (inode) |
| 254 | audit_log_format(ab, " dev=%s ino=%lu", |
| 255 | inode->i_sb->s_id, |
| 256 | inode->i_ino); |
| 257 | break; |
| 258 | case LSM_AUDIT_DATA_TASK: |
| 259 | tsk = a->u.tsk; |
| 260 | if (tsk && tsk->pid) { |
| 261 | audit_log_format(ab, " pid=%d comm=", tsk->pid); |
| 262 | audit_log_untrustedstring(ab, tsk->comm); |
| 263 | } |
| 264 | break; |
| 265 | case LSM_AUDIT_DATA_NET: |
| 266 | if (a->u.net.sk) { |
| 267 | struct sock *sk = a->u.net.sk; |
| 268 | struct unix_sock *u; |
| 269 | int len = 0; |
| 270 | char *p = NULL; |
| 271 | |
| 272 | switch (sk->sk_family) { |
| 273 | case AF_INET: { |
| 274 | struct inet_sock *inet = inet_sk(sk); |
| 275 | |
Eric Dumazet | c720c7e8 | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 276 | print_ipv4_addr(ab, inet->inet_rcv_saddr, |
| 277 | inet->inet_sport, |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 278 | "laddr", "lport"); |
Eric Dumazet | c720c7e8 | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 279 | print_ipv4_addr(ab, inet->inet_daddr, |
| 280 | inet->inet_dport, |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 281 | "faddr", "fport"); |
| 282 | break; |
| 283 | } |
| 284 | case AF_INET6: { |
| 285 | struct inet_sock *inet = inet_sk(sk); |
| 286 | struct ipv6_pinfo *inet6 = inet6_sk(sk); |
| 287 | |
| 288 | print_ipv6_addr(ab, &inet6->rcv_saddr, |
Eric Dumazet | c720c7e8 | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 289 | inet->inet_sport, |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 290 | "laddr", "lport"); |
| 291 | print_ipv6_addr(ab, &inet6->daddr, |
Eric Dumazet | c720c7e8 | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 292 | inet->inet_dport, |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 293 | "faddr", "fport"); |
| 294 | break; |
| 295 | } |
| 296 | case AF_UNIX: |
| 297 | u = unix_sk(sk); |
| 298 | if (u->dentry) { |
| 299 | struct path path = { |
| 300 | .dentry = u->dentry, |
| 301 | .mnt = u->mnt |
| 302 | }; |
| 303 | audit_log_d_path(ab, "path=", &path); |
| 304 | break; |
| 305 | } |
| 306 | if (!u->addr) |
| 307 | break; |
| 308 | len = u->addr->len-sizeof(short); |
| 309 | p = &u->addr->name->sun_path[0]; |
| 310 | audit_log_format(ab, " path="); |
| 311 | if (*p) |
| 312 | audit_log_untrustedstring(ab, p); |
| 313 | else |
| 314 | audit_log_n_hex(ab, p, len); |
| 315 | break; |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | switch (a->u.net.family) { |
| 320 | case AF_INET: |
| 321 | print_ipv4_addr(ab, a->u.net.v4info.saddr, |
| 322 | a->u.net.sport, |
| 323 | "saddr", "src"); |
| 324 | print_ipv4_addr(ab, a->u.net.v4info.daddr, |
| 325 | a->u.net.dport, |
| 326 | "daddr", "dest"); |
| 327 | break; |
| 328 | case AF_INET6: |
| 329 | print_ipv6_addr(ab, &a->u.net.v6info.saddr, |
| 330 | a->u.net.sport, |
| 331 | "saddr", "src"); |
| 332 | print_ipv6_addr(ab, &a->u.net.v6info.daddr, |
| 333 | a->u.net.dport, |
| 334 | "daddr", "dest"); |
| 335 | break; |
| 336 | } |
| 337 | if (a->u.net.netif > 0) { |
| 338 | struct net_device *dev; |
| 339 | |
| 340 | /* NOTE: we always use init's namespace */ |
| 341 | dev = dev_get_by_index(&init_net, a->u.net.netif); |
| 342 | if (dev) { |
| 343 | audit_log_format(ab, " netif=%s", dev->name); |
| 344 | dev_put(dev); |
| 345 | } |
| 346 | } |
| 347 | break; |
| 348 | #ifdef CONFIG_KEYS |
| 349 | case LSM_AUDIT_DATA_KEY: |
| 350 | audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); |
| 351 | if (a->u.key_struct.key_desc) { |
| 352 | audit_log_format(ab, " key_desc="); |
| 353 | audit_log_untrustedstring(ab, a->u.key_struct.key_desc); |
| 354 | } |
| 355 | break; |
| 356 | #endif |
Eric Paris | dd8dbf2 | 2009-11-03 16:35:32 +1100 | [diff] [blame] | 357 | case LSM_AUDIT_DATA_KMOD: |
| 358 | audit_log_format(ab, " kmod="); |
| 359 | audit_log_untrustedstring(ab, a->u.kmod_name); |
| 360 | break; |
Etienne Basset | 6e837fb | 2009-04-08 20:39:40 +0200 | [diff] [blame] | 361 | } /* switch (a->type) */ |
| 362 | } |
| 363 | |
| 364 | /** |
| 365 | * common_lsm_audit - generic LSM auditing function |
| 366 | * @a: auxiliary audit data |
| 367 | * |
| 368 | * setup the audit buffer for common security information |
| 369 | * uses callback to print LSM specific information |
| 370 | */ |
| 371 | void common_lsm_audit(struct common_audit_data *a) |
| 372 | { |
| 373 | struct audit_buffer *ab; |
| 374 | |
| 375 | if (a == NULL) |
| 376 | return; |
| 377 | /* we use GFP_ATOMIC so we won't sleep */ |
| 378 | ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); |
| 379 | |
| 380 | if (ab == NULL) |
| 381 | return; |
| 382 | |
| 383 | if (a->lsm_pre_audit) |
| 384 | a->lsm_pre_audit(ab, a); |
| 385 | |
| 386 | dump_common_audit_data(ab, a); |
| 387 | |
| 388 | if (a->lsm_post_audit) |
| 389 | a->lsm_post_audit(ab, a); |
| 390 | |
| 391 | audit_log_end(ab); |
| 392 | } |