From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Subject: Re: [RFC PATCH 2/5] sctp: Add ip option support Date: Tue, 31 Oct 2017 15:06:06 -0200 Message-ID: <20171031170606.GD3675@localhost.localdomain> References: <20171017135806.4244-1-richard_c_haines@btinternet.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: selinux@tycho.nsa.gov, netdev@vger.kernel.org, linux-sctp@vger.kernel.org, linux-security-module@vger.kernel.org, paul@paul-moore.com, vyasevich@gmail.com, nhorman@tuxdriver.com, sds@tycho.nsa.gov, eparis@parisplace.org To: Richard Haines Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52036 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753474AbdJaRGK (ORCPT ); Tue, 31 Oct 2017 13:06:10 -0400 Content-Disposition: inline In-Reply-To: <20171017135806.4244-1-richard_c_haines@btinternet.com> Sender: netdev-owner@vger.kernel.org List-ID: Hello, On Tue, Oct 17, 2017 at 02:58:06PM +0100, Richard Haines wrote: > 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); Please add a var for sctp_sk(asoc->base.sk)->pf->af. That should also help to not break the dereferencing into multiple lines. > + > 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; Seems we need RCU protection here. And please add a var for inet6->opt. > + 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); Here you may also add a var for sp->pf->af. > } 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; Also here. May even be inside the if() block. Thanks > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >