From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Haines Subject: [RFC PATCH 2/5] sctp: Add ip option support Date: Tue, 17 Oct 2017 14:58:06 +0100 Message-ID: <20171017135806.4244-1-richard_c_haines@btinternet.com> Cc: paul@paul-moore.com, vyasevich@gmail.com, nhorman@tuxdriver.com, sds@tycho.nsa.gov, eparis@parisplace.org, marcelo.leitner@gmail.com, Richard Haines To: selinux@tycho.nsa.gov, netdev@vger.kernel.org, linux-sctp@vger.kernel.org, linux-security-module@vger.kernel.org Return-path: Received: from rgout0604.bt.lon5.cpcloud.co.uk ([65.20.0.131]:17514 "EHLO rgout06.bt.lon5.cpcloud.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750853AbdJQOBJ (ORCPT ); Tue, 17 Oct 2017 10:01:09 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Add ip option support to allow LSM security modules to utilise CIPSO/IPv4 and CALIPSO/IPv6 services. Signed-off-by: Richard Haines --- include/net/sctp/structs.h | 2 ++ net/sctp/chunk.c | 7 ++++--- net/sctp/ipv6.c | 37 ++++++++++++++++++++++++++++++------- net/sctp/output.c | 3 ++- net/sctp/protocol.c | 36 ++++++++++++++++++++++++++++++++++++ net/sctp/socket.c | 5 ++++- 6 files changed, 78 insertions(+), 12 deletions(-) diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h index 5ab29af..7767577 100644 --- a/include/net/sctp/structs.h +++ b/include/net/sctp/structs.h @@ -461,6 +461,7 @@ 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; }; @@ -485,6 +486,7 @@ 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 1323d41..e49e240 100644 --- a/net/sctp/chunk.c +++ b/net/sctp/chunk.c @@ -153,7 +153,6 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu chunk->msg = msg; } - /* A data chunk can have a maximum payload of (2^16 - 20). Break * down any such message into smaller chunks. Opportunistically, fragment * the chunks down to the current MTU constraints. We may get refragmented @@ -190,7 +189,10 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, */ max_data = asoc->pathmtu - sctp_sk(asoc->base.sk)->pf->af->net_header_len - - sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk); + sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk) - + sctp_sk(asoc->base.sk)->pf->af-> + ip_options_len(asoc->base.sk); + max_data = SCTP_TRUNC4(max_data); /* If the the peer requested that we authenticate DATA chunks @@ -210,7 +212,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, /* Set first_len and then account for possible bundles on first frag */ first_len = max_data; - /* Check to see if we have a pending SACK and try to let it be bundled * with this message. Do this if we don't have any data queued already. * To check that, look at out_qlen and retransmit list. diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c index a4b6ffb..49c9011 100644 --- a/net/sctp/ipv6.c +++ b/net/sctp/ipv6.c @@ -423,6 +423,33 @@ 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); + 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 *inet6 = inet6_sk(sk); + + if (inet6->opt) + return inet6->opt->opt_flen + inet6->opt->opt_nflen; + else + return 0; +} + /* 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) @@ -662,7 +689,6 @@ 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) @@ -685,12 +711,7 @@ 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(). @@ -1033,6 +1054,7 @@ 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, @@ -1051,6 +1073,7 @@ 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 9d85049..85bcd5b 100644 --- a/net/sctp/output.c +++ b/net/sctp/output.c @@ -151,7 +151,8 @@ void sctp_packet_init(struct sctp_packet *packet, INIT_LIST_HEAD(&packet->chunk_list); if (asoc) { struct sctp_sock *sp = sctp_sk(asoc->base.sk); - overhead = sp->pf->af->net_header_len; + overhead = sp->pf->af->net_header_len + + sp->pf->af->ip_options_len(asoc->base.sk); } else { overhead = sizeof(struct ipv6hdr); } diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c index 989a900..a9e54ac 100644 --- a/net/sctp/protocol.c +++ b/net/sctp/protocol.c @@ -237,6 +237,38 @@ 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); + } + 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); + + if (inet->inet_opt) + return inet->inet_opt->opt.optlen; + else + return 0; +} + /* 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) @@ -590,6 +622,8 @@ 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; @@ -1008,6 +1042,7 @@ 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 }; @@ -1092,6 +1127,7 @@ 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 8d76086..70355a0 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3124,6 +3124,7 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned if (asoc) { if (val == 0) { val = asoc->pathmtu; + val -= sp->pf->af->ip_options_len(asoc->base.sk); val -= sp->pf->af->net_header_len; val -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk); @@ -4917,9 +4918,11 @@ 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. -- 2.13.6