Add ip option support to allow LSM security modules to utilise CIPSO/IPv4 and CALIPSO/IPv6 services.
Signed-off-by: Richard Haines <richard_c_hai...@btinternet.com> --- All SCTP lksctp-tools/src/func_tests run correctly in enforcing mode. All "./sctp-tests run" obtained from: https://github.com/sctp/sctp-tests pass. V7 Changes: 1) Log when copy ip options fail for IPv4 and IPv6 2) Correct sctp_setsockopt_maxseg() function. Note that the lksctp-tools func_tests do not test with struct sctp_assoc_value. Just used simple test and okay. 3) Move calculation of overheads to sctp_packet_config(). NOTE: Initially in sctp_packet_reset() I set packet->size and packet->overhead to zero (as it is a reset). This was okay for all the lksctp-tools function tests, however when running "sctp-tests" ndatshched tests it causes these to fail with an st_s.log entry of: sid: 3, expected: 3 sid: 3, expected: 3 unexpected sid packet !!! sid: 1, expected: 3 I then found sctp_packet_transmit() relies on setting "packet->size = packet->overhead;" to reset size to the current overhead after sending packets, hence the comment in sctp_packet_reset() V8 Change: Fix sparse warning: net/sctp/protocol.c:269:28: sparse: dereference of noderef expression highlighted in [1] for sctp_v4_ip_options_len() function. [1] https://lists.01.org/pipermail/kbuild-all/2018-February/043695.html include/net/sctp/sctp.h | 4 +++- include/net/sctp/structs.h | 2 ++ net/sctp/chunk.c | 10 +++++++--- net/sctp/ipv6.c | 45 ++++++++++++++++++++++++++++++++++++++------- net/sctp/output.c | 34 +++++++++++++++++++++------------- net/sctp/protocol.c | 43 +++++++++++++++++++++++++++++++++++++++++++ net/sctp/socket.c | 11 ++++++++--- 7 files changed, 122 insertions(+), 27 deletions(-) diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index f7ae6b0..25c5c87 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -441,9 +441,11 @@ static inline int sctp_list_single_entry(struct list_head *head) static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu) { struct sctp_sock *sp = sctp_sk(asoc->base.sk); + struct sctp_af *af = sp->pf->af; int frag = pmtu; - frag -= sp->pf->af->net_header_len; + frag -= af->ip_options_len(asoc->base.sk); + frag -= af->net_header_len; frag -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream); if (asoc->user_frag) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 03e92dd..ead5fce 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -491,6 +491,7 @@ struct sctp_af { void (*ecn_capable)(struct sock *sk); __u16 net_header_len; int sockaddr_len; + int (*ip_options_len)(struct sock *sk); sa_family_t sa_family; struct list_head list; }; @@ -515,6 +516,7 @@ struct sctp_pf { int (*addr_to_user)(struct sctp_sock *sk, union sctp_addr *addr); void (*to_sk_saddr)(union sctp_addr *, struct sock *sk); void (*to_sk_daddr)(union sctp_addr *, struct sock *sk); + void (*copy_ip_options)(struct sock *sk, struct sock *newsk); struct sctp_af *af; }; diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c index 991a530..d726d21 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -171,6 +171,8 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, struct list_head *pos, *temp; struct sctp_chunk *chunk; struct sctp_datamsg *msg; + struct sctp_sock *sp; + struct sctp_af *af; int err; msg = sctp_datamsg_new(GFP_KERNEL); @@ -189,9 +191,11 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, /* This is the biggest possible DATA chunk that can fit into * the packet */ - max_data = asoc->pathmtu - - sctp_sk(asoc->base.sk)->pf->af->net_header_len - - sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream); + sp = sctp_sk(asoc->base.sk); + af = sp->pf->af; + max_data = asoc->pathmtu - af->net_header_len - + sizeof(struct sctphdr) - sctp_datachk_len(&asoc->stream) - + af->ip_options_len(asoc->base.sk); max_data = SCTP_TRUNC4(max_data); /* If the the peer requested that we authenticate DATA chunks diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index e35d4f7..30a05a8 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -427,6 +427,41 @@ static void sctp_v6_copy_addrlist(struct list_head *addrlist, rcu_read_unlock(); } +/* Copy over any ip options */ +static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) +{ + struct ipv6_pinfo *newnp, *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + + newnp = inet6_sk(newsk); + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) { + opt = ipv6_dup_options(newsk, opt); + if (!opt) + pr_err("%s: Failed to copy ip options\n", __func__); + } + RCU_INIT_POINTER(newnp->opt, opt); + rcu_read_unlock(); +} + +/* Account for the IP options */ +static int sctp_v6_ip_options_len(struct sock *sk) +{ + struct ipv6_pinfo *np = inet6_sk(sk); + struct ipv6_txoptions *opt; + int len = 0; + + rcu_read_lock(); + opt = rcu_dereference(np->opt); + if (opt) + len = opt->opt_flen + opt->opt_nflen; + + rcu_read_unlock(); + return len; +} + /* Initialize a sockaddr_storage from in incoming skb. */ static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, int is_saddr) @@ -666,7 +701,6 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, struct sock *newsk; struct ipv6_pinfo *newnp, *np = inet6_sk(sk); struct sctp6_sock *newsctp6sk; - struct ipv6_txoptions *opt; newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); if (!newsk) @@ -689,12 +723,7 @@ static struct sock *sctp_v6_create_accept_sk(struct sock *sk, newnp->ipv6_ac_list = NULL; newnp->ipv6_fl_list = NULL; - rcu_read_lock(); - opt = rcu_dereference(np->opt); - if (opt) - opt = ipv6_dup_options(newsk, opt); - RCU_INIT_POINTER(newnp->opt, opt); - rcu_read_unlock(); + sctp_v6_copy_ip_options(sk, newsk); /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() * and getpeername(). @@ -1041,6 +1070,7 @@ static struct sctp_af sctp_af_inet6 = { .ecn_capable = sctp_v6_ecn_capable, .net_header_len = sizeof(struct ipv6hdr), .sockaddr_len = sizeof(struct sockaddr_in6), + .ip_options_len = sctp_v6_ip_options_len, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_ipv6_setsockopt, .compat_getsockopt = compat_ipv6_getsockopt, @@ -1059,6 +1089,7 @@ static struct sctp_pf sctp_pf_inet6 = { .addr_to_user = sctp_v6_addr_to_user, .to_sk_saddr = sctp_v6_to_sk_saddr, .to_sk_daddr = sctp_v6_to_sk_daddr, + .copy_ip_options = sctp_v6_copy_ip_options, .af = &sctp_af_inet6, }; diff --git a/net/sctp/output.c b/net/sctp/output.c index 01a26ee..a58d13c 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -69,7 +69,11 @@ static enum sctp_xmit sctp_packet_will_fit(struct sctp_packet *packet, static void sctp_packet_reset(struct sctp_packet *packet) { + /* sctp_packet_transmit() relies on this to reset size to the + * current overhead after sending packets. + */ packet->size = packet->overhead; + packet->has_cookie_echo = 0; packet->has_sack = 0; packet->has_data = 0; @@ -87,6 +91,7 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, struct sctp_transport *tp = packet->transport; struct sctp_association *asoc = tp->asoc; struct sock *sk; + size_t overhead = sizeof(struct ipv6hdr) + sizeof(struct sctphdr); pr_debug("%s: packet:%p vtag:0x%x\n", __func__, packet, vtag); packet->vtag = vtag; @@ -95,10 +100,22 @@ void sctp_packet_config(struct sctp_packet *packet, __u32 vtag, if (!sctp_packet_empty(packet)) return; - /* set packet max_size with pathmtu */ + /* set packet max_size with pathmtu, then calculate overhead */ packet->max_size = tp->pathmtu; - if (!asoc) + if (asoc) { + struct sctp_sock *sp = sctp_sk(asoc->base.sk); + struct sctp_af *af = sp->pf->af; + + overhead = af->net_header_len + + af->ip_options_len(asoc->base.sk); + overhead += sizeof(struct sctphdr); + packet->overhead = overhead; + packet->size = overhead; + } else { + packet->overhead = overhead; + packet->size = overhead; return; + } /* update dst or transport pathmtu if in need */ sk = asoc->base.sk; @@ -140,23 +157,14 @@ void sctp_packet_init(struct sctp_packet *packet, struct sctp_transport *transport, __u16 sport, __u16 dport) { - struct sctp_association *asoc = transport->asoc; - size_t overhead; - pr_debug("%s: packet:%p transport:%p\n", __func__, packet, transport); packet->transport = transport; packet->source_port = sport; packet->destination_port = dport; INIT_LIST_HEAD(&packet->chunk_list); - if (asoc) { - struct sctp_sock *sp = sctp_sk(asoc->base.sk); - overhead = sp->pf->af->net_header_len; - } else { - overhead = sizeof(struct ipv6hdr); - } - overhead += sizeof(struct sctphdr); - packet->overhead = overhead; + /* The overhead will be calculated by sctp_packet_config() */ + packet->overhead = 0; sctp_packet_reset(packet); packet->vtag = 0; } diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 91813e6..02f23ad 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -237,6 +237,45 @@ int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp, return error; } +/* Copy over any ip options */ +static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk) +{ + struct inet_sock *newinet, *inet = inet_sk(sk); + struct ip_options_rcu *inet_opt, *newopt = NULL; + + newinet = inet_sk(newsk); + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) { + newopt = sock_kmalloc(newsk, sizeof(*inet_opt) + + inet_opt->opt.optlen, GFP_ATOMIC); + if (newopt) + memcpy(newopt, inet_opt, sizeof(*inet_opt) + + inet_opt->opt.optlen); + else + pr_err("%s: Failed to copy ip options\n", __func__); + } + RCU_INIT_POINTER(newinet->inet_opt, newopt); + rcu_read_unlock(); +} + +/* Account for the IP options */ +static int sctp_v4_ip_options_len(struct sock *sk) +{ + struct inet_sock *inet = inet_sk(sk); + struct ip_options_rcu *inet_opt; + int len = 0; + + rcu_read_lock(); + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt) + len = inet_opt->opt.optlen; + + rcu_read_unlock(); + return len; +} + /* Initialize a sctp_addr from in incoming skb. */ static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb, int is_saddr) @@ -588,6 +627,8 @@ static struct sock *sctp_v4_create_accept_sk(struct sock *sk, sctp_copy_sock(newsk, sk, asoc); sock_reset_flag(newsk, SOCK_ZAPPED); + sctp_v4_copy_ip_options(sk, newsk); + newinet = inet_sk(newsk); newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr; @@ -1006,6 +1047,7 @@ static struct sctp_pf sctp_pf_inet = { .addr_to_user = sctp_v4_addr_to_user, .to_sk_saddr = sctp_v4_to_sk_saddr, .to_sk_daddr = sctp_v4_to_sk_daddr, + .copy_ip_options = sctp_v4_copy_ip_options, .af = &sctp_af_inet }; @@ -1090,6 +1132,7 @@ static struct sctp_af sctp_af_inet = { .ecn_capable = sctp_v4_ecn_capable, .net_header_len = sizeof(struct iphdr), .sockaddr_len = sizeof(struct sockaddr_in), + .ip_options_len = sctp_v4_ip_options_len, #ifdef CONFIG_COMPAT .compat_setsockopt = compat_ip_setsockopt, .compat_getsockopt = compat_ip_getsockopt, diff --git a/net/sctp/socket.c b/net/sctp/socket.c index bf271f8..eb55c63 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3138,6 +3138,7 @@ static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, unsign static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned int optlen) { struct sctp_sock *sp = sctp_sk(sk); + struct sctp_af *af = sp->pf->af; struct sctp_assoc_value params; struct sctp_association *asoc; int val; @@ -3162,7 +3163,8 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned if (val) { int min_len, max_len; - min_len = SCTP_DEFAULT_MINSEGMENT - sp->pf->af->net_header_len; + min_len = SCTP_DEFAULT_MINSEGMENT - af->net_header_len; + min_len -= af->ip_options_len(sk); min_len -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); @@ -3175,7 +3177,8 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned asoc = sctp_id2assoc(sk, params.assoc_id); if (asoc) { if (val == 0) { - val = asoc->pathmtu - sp->pf->af->net_header_len; + val = asoc->pathmtu - af->net_header_len; + val -= af->ip_options_len(sk); val -= sizeof(struct sctphdr) + sctp_datachk_len(&asoc->stream); } @@ -5087,9 +5090,11 @@ int sctp_do_peeloff(struct sock *sk, sctp_assoc_t id, struct socket **sockp) sctp_copy_sock(sock->sk, sk, asoc); /* Make peeled-off sockets more like 1-1 accepted sockets. - * Set the daddr and initialize id to something more random + * Set the daddr and initialize id to something more random and also + * copy over any ip options. */ sp->pf->to_sk_daddr(&asoc->peer.primary_addr, sk); + sp->pf->copy_ip_options(sk, sock->sk); /* Populate the fields of the newsk from the oldsk and migrate the * asoc to the newsk. -- 2.14.3
