/* * common LSM auditing functions * * Based on code written for SELinux by : * Stephen Smalley, <sds@epoch.ncsc.mil> * James Morris <jmorris@redhat.com> * Author : Etienne Basset, <etienne.basset@ensta.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, * as published by the Free Software Foundation. */ #include <linux/types.h> #include <linux/stddef.h> #include <linux/kernel.h> #include <linux/fs.h> #include <linux/init.h> #include <net/sock.h> #include <linux/un.h> #include <net/af_unix.h> #include <linux/audit.h> #include <linux/ipv6.h> #include <linux/ip.h> #include <net/ip.h> #include <net/ipv6.h> #include <linux/tcp.h> #include <linux/udp.h> #include <linux/dccp.h> #include <linux/sctp.h> #include <linux/lsm_audit.h> /** * ipv4_skb_to_auditdata : fill auditdata from skb * @skb : the skb * @ad : the audit data to fill * @proto : the layer 4 protocol * * return 0 on success */ int ipv4_skb_to_auditdata(struct sk_buff *skb, struct common_audit_data *ad, u8 *proto) { int ret = 0; struct iphdr *ih; ih = ip_hdr(skb); if (ih == NULL) return -EINVAL; ad->u.net.v4info.saddr = ih->saddr; ad->u.net.v4info.daddr = ih->daddr; if (proto) *proto = ih->protocol; /* non initial fragment */ if (ntohs(ih->frag_off) & IP_OFFSET) return 0; switch (ih->protocol) { case IPPROTO_TCP: { struct tcphdr *th = tcp_hdr(skb); if (th == NULL) break; ad->u.net.sport = th->source; ad->u.net.dport = th->dest; break; } case IPPROTO_UDP: { struct udphdr *uh = udp_hdr(skb); if (uh == NULL) break; ad->u.net.sport = uh->source; ad->u.net.dport = uh->dest; break; } case IPPROTO_DCCP: { struct dccp_hdr *dh = dccp_hdr(skb); if (dh == NULL) break; ad->u.net.sport = dh->dccph_sport; ad->u.net.dport = dh->dccph_dport; break; } case IPPROTO_SCTP: { struct sctphdr *sh = sctp_hdr(skb); if (sh == NULL) break; ad->u.net.sport = sh->source; ad->u.net.dport = sh->dest; break; } default: ret = -EINVAL; } return ret; } #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) /** * ipv6_skb_to_auditdata : fill auditdata from skb * @skb : the skb * @ad : the audit data to fill * @proto : the layer 4 protocol * * return 0 on success */ int ipv6_skb_to_auditdata(struct sk_buff *skb, struct common_audit_data *ad, u8 *proto) { int offset, ret = 0; struct ipv6hdr *ip6; u8 nexthdr; ip6 = ipv6_hdr(skb); if (ip6 == NULL) return -EINVAL; ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr); ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr); ret = 0; /* IPv6 can have several extension header before the Transport header * skip them */ offset = skb_network_offset(skb); offset += sizeof(*ip6); nexthdr = ip6->nexthdr; offset = ipv6_skip_exthdr(skb, offset, &nexthdr); if (offset < 0) return 0; if (proto) *proto = nexthdr; switch (nexthdr) { case IPPROTO_TCP: { struct tcphdr _tcph, *th; th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); if (th == NULL) break; ad->u.net.sport = th->source; ad->u.net.dport = th->dest; break; } case IPPROTO_UDP: { struct udphdr _udph, *uh; uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); if (uh == NULL) break; ad->u.net.sport = uh->source; ad->u.net.dport = uh->dest; break; } case IPPROTO_DCCP: { struct dccp_hdr _dccph, *dh; dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); if (dh == NULL) break; ad->u.net.sport = dh->dccph_sport; ad->u.net.dport = dh->dccph_dport; break; } case IPPROTO_SCTP: { struct sctphdr _sctph, *sh; sh = skb_header_pointer(skb, offset, sizeof(_sctph), &_sctph); if (sh == NULL) break; ad->u.net.sport = sh->source; ad->u.net.dport = sh->dest; break; } default: ret = -EINVAL; } return ret; } #endif static inline void print_ipv6_addr(struct audit_buffer *ab, struct in6_addr *addr, __be16 port, char *name1, char *name2) { if (!ipv6_addr_any(addr)) audit_log_format(ab, " %s=%pI6c", name1, addr); if (port) audit_log_format(ab, " %s=%d", name2, ntohs(port)); } static inline void print_ipv4_addr(struct audit_buffer *ab, __be32 addr, __be16 port, char *name1, char *name2) { if (addr) audit_log_format(ab, " %s=%pI4", name1, &addr); if (port) audit_log_format(ab, " %s=%d", name2, ntohs(port)); } /** * dump_common_audit_data - helper to dump common audit data * @a : common audit data * */ static void dump_common_audit_data(struct audit_buffer *ab, struct common_audit_data *a) { struct inode *inode = NULL; struct task_struct *tsk = current; if (a->tsk) tsk = a->tsk; if (tsk && tsk->pid) { audit_log_format(ab, " pid=%d comm=", tsk->pid); audit_log_untrustedstring(ab, tsk->comm); } switch (a->type) { case LSM_AUDIT_NO_AUDIT: return; case LSM_AUDIT_DATA_IPC: audit_log_format(ab, " key=%d ", a->u.ipc_id); break; case LSM_AUDIT_DATA_CAP: audit_log_format(ab, " capability=%d ", a->u.cap); break; case LSM_AUDIT_DATA_FS: if (a->u.fs.path.dentry) { struct dentry *dentry = a->u.fs.path.dentry; if (a->u.fs.path.mnt) { audit_log_d_path(ab, "path=", &a->u.fs.path); } else { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, dentry->d_name.name); } inode = dentry->d_inode; } else if (a->u.fs.inode) { struct dentry *dentry; inode = a->u.fs.inode; dentry = d_find_alias(inode); if (dentry) { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, dentry->d_name.name); dput(dentry); } } if (inode) audit_log_format(ab, " dev=%s ino=%lu", inode->i_sb->s_id, inode->i_ino); break; case LSM_AUDIT_DATA_TASK: tsk = a->u.tsk; if (tsk && tsk->pid) { audit_log_format(ab, " pid=%d comm=", tsk->pid); audit_log_untrustedstring(ab, tsk->comm); } break; case LSM_AUDIT_DATA_NET: if (a->u.net.sk) { struct sock *sk = a->u.net.sk; struct unix_sock *u; int len = 0; char *p = NULL; switch (sk->sk_family) { case AF_INET: { struct inet_sock *inet = inet_sk(sk); print_ipv4_addr(ab, inet->rcv_saddr, inet->sport, "laddr", "lport"); print_ipv4_addr(ab, inet->daddr, inet->dport, "faddr", "fport"); break; } case AF_INET6: { struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *inet6 = inet6_sk(sk); print_ipv6_addr(ab, &inet6->rcv_saddr, inet->sport, "laddr", "lport"); print_ipv6_addr(ab, &inet6->daddr, inet->dport, "faddr", "fport"); break; } case AF_UNIX: u = unix_sk(sk); if (u->dentry) { struct path path = { .dentry = u->dentry, .mnt = u->mnt }; audit_log_d_path(ab, "path=", &path); break; } if (!u->addr) break; len = u->addr->len-sizeof(short); p = &u->addr->name->sun_path[0]; audit_log_format(ab, " path="); if (*p) audit_log_untrustedstring(ab, p); else audit_log_n_hex(ab, p, len); break; } } switch (a->u.net.family) { case AF_INET: print_ipv4_addr(ab, a->u.net.v4info.saddr, a->u.net.sport, "saddr", "src"); print_ipv4_addr(ab, a->u.net.v4info.daddr, a->u.net.dport, "daddr", "dest"); break; case AF_INET6: print_ipv6_addr(ab, &a->u.net.v6info.saddr, a->u.net.sport, "saddr", "src"); print_ipv6_addr(ab, &a->u.net.v6info.daddr, a->u.net.dport, "daddr", "dest"); break; } if (a->u.net.netif > 0) { struct net_device *dev; /* NOTE: we always use init's namespace */ dev = dev_get_by_index(&init_net, a->u.net.netif); if (dev) { audit_log_format(ab, " netif=%s", dev->name); dev_put(dev); } } break; #ifdef CONFIG_KEYS case LSM_AUDIT_DATA_KEY: audit_log_format(ab, " key_serial=%u", a->u.key_struct.key); if (a->u.key_struct.key_desc) { audit_log_format(ab, " key_desc="); audit_log_untrustedstring(ab, a->u.key_struct.key_desc); } break; #endif } /* switch (a->type) */ } /** * common_lsm_audit - generic LSM auditing function * @a: auxiliary audit data * * setup the audit buffer for common security information * uses callback to print LSM specific information */ void common_lsm_audit(struct common_audit_data *a) { struct audit_buffer *ab; if (a == NULL) return; /* we use GFP_ATOMIC so we won't sleep */ ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_AVC); if (ab == NULL) return; if (a->lsm_pre_audit) a->lsm_pre_audit(ab, a); dump_common_audit_data(ab, a); if (a->lsm_post_audit) a->lsm_post_audit(ab, a); audit_log_end(ab); }