From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: Re: [PATCH net] sctp: do not check port in sctp_inet6_cmp_addr Date: Wed, 11 Apr 2018 15:59:26 -0400 Message-ID: <20180411195926.GB4141@hmswarspite.think-freely.org> References: <340aad3be762046ca9d02e54edba5bfefa2f4e71.1523451485.git.lucien.xin@gmail.com> <20180411143607.GA4141@hmswarspite.think-freely.org> <20180411145910.GC3711@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Marcelo Ricardo Leitner , network dev , linux-sctp@vger.kernel.org, davem To: Xin Long Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:40441 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756754AbeDKUAD (ORCPT ); Wed, 11 Apr 2018 16:00:03 -0400 Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Apr 12, 2018 at 12:16:58AM +0800, Xin Long wrote: > On Wed, Apr 11, 2018 at 10:59 PM, Marcelo Ricardo Leitner > wrote: > > On Wed, Apr 11, 2018 at 10:36:07AM -0400, Neil Horman wrote: > >> On Wed, Apr 11, 2018 at 08:58:05PM +0800, Xin Long wrote: > >> > pf->cmp_addr() is called before binding a v6 address to the sock. It > >> > should not check ports, like in sctp_inet_cmp_addr. > >> > > >> > But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr, > >> > sctp_v6_cmp_addr where it also compares the ports. > >> > > >> > This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind > >> > multiple duplicated IPv6 addresses after Commit 40b4f0fd74e4 ("sctp: > >> > lack the check for ports in sctp_v6_cmp_addr"). > >> > > >> > This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr, > >> > but do the proper check for both v6 addrs and v4mapped addrs. > >> > > >> > Fixes: 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr") > >> > Reported-by: Jianwen Ji > >> > Signed-off-by: Xin Long > >> > --- > >> > net/sctp/ipv6.c | 27 ++++++++++++++++++++++++--- > >> > 1 file changed, 24 insertions(+), 3 deletions(-) > >> > > >> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > >> > index f1fc48e..be4b72c 100644 > >> > --- a/net/sctp/ipv6.c > >> > +++ b/net/sctp/ipv6.c > >> > @@ -846,8 +846,8 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, > >> > const union sctp_addr *addr2, > >> > struct sctp_sock *opt) > >> > { > >> > - struct sctp_af *af1, *af2; > >> > struct sock *sk = sctp_opt2sk(opt); > >> > + struct sctp_af *af1, *af2; > >> > > >> > af1 = sctp_get_af_specific(addr1->sa.sa_family); > >> > af2 = sctp_get_af_specific(addr2->sa.sa_family); > >> > @@ -863,10 +863,31 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, > >> > if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) > >> > return 1; > >> > > >> > - if (addr1->sa.sa_family != addr2->sa.sa_family) > >> > + if (addr1->sa.sa_family != addr2->sa.sa_family) { > >> > + if (addr1->sa.sa_family == AF_INET && > >> > + addr2->sa.sa_family == AF_INET6 && > >> > + ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) > >> > + if (addr2->v6.sin6_addr.s6_addr32[3] == > >> > + addr1->v4.sin_addr.s_addr) > >> > + return 1; > >> > + if (addr2->sa.sa_family == AF_INET && > >> > + addr1->sa.sa_family == AF_INET6 && > >> > + ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) > >> > + if (addr1->v6.sin6_addr.s6_addr32[3] == > >> > + addr2->v4.sin_addr.s_addr) > >> > + return 1; > >> > + return 0; > >> > + } > >> > + > >> > + if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) > >> > + return 0; > >> > + > >> > + if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && > >> > + addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && > >> > + addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) > >> > return 0; > >> > > >> > - return af1->cmp_addr(addr1, addr2); > >> > + return 1; > >> > } > >> > > >> > /* Verify that the provided sockaddr looks bindable. Common verification, > >> > -- > >> > 2.1.0 > >> > > >> This looks correct to me, but is it worth duplicating the comparison code like > >> this from the cmp_addr function? It might be more worthwhile to add a flag to > >> the cmp_addr method to direct weather it needs to check port values or not. > >> That way you could continue to use the cmp_addr function here. > > > > Adding a flag into sctp_v6_cmp_addr will get us a terrible code to > > read. It's already not one of the best looking part of it. Maybe > > still duplicate part of it it, but at 'af' level? As in: > > - af->cmp_addr > > - af->cmp_addr_port > > > What do you think of: > > static int sctp_v6_cmp_addr(const union sctp_addr *addr1, > const union sctp_addr *addr2) > { > return __sctp_v6_cmp_addr(addr1, addr2) && > addr1->v6.sin_port == addr2->v6.sin_port; > } > > (v6.sin_port and v4.sin_port have the same offset in union sctp_addr, > we've exploited this in many places in SCTP) Yes, I'd be ok with that Neil > -- > 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 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Date: Wed, 11 Apr 2018 19:59:26 +0000 Subject: Re: [PATCH net] sctp: do not check port in sctp_inet6_cmp_addr Message-Id: <20180411195926.GB4141@hmswarspite.think-freely.org> List-Id: References: <340aad3be762046ca9d02e54edba5bfefa2f4e71.1523451485.git.lucien.xin@gmail.com> <20180411143607.GA4141@hmswarspite.think-freely.org> <20180411145910.GC3711@localhost.localdomain> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Xin Long Cc: Marcelo Ricardo Leitner , network dev , linux-sctp@vger.kernel.org, davem On Thu, Apr 12, 2018 at 12:16:58AM +0800, Xin Long wrote: > On Wed, Apr 11, 2018 at 10:59 PM, Marcelo Ricardo Leitner > wrote: > > On Wed, Apr 11, 2018 at 10:36:07AM -0400, Neil Horman wrote: > >> On Wed, Apr 11, 2018 at 08:58:05PM +0800, Xin Long wrote: > >> > pf->cmp_addr() is called before binding a v6 address to the sock. It > >> > should not check ports, like in sctp_inet_cmp_addr. > >> > > >> > But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr, > >> > sctp_v6_cmp_addr where it also compares the ports. > >> > > >> > This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind > >> > multiple duplicated IPv6 addresses after Commit 40b4f0fd74e4 ("sctp: > >> > lack the check for ports in sctp_v6_cmp_addr"). > >> > > >> > This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr, > >> > but do the proper check for both v6 addrs and v4mapped addrs. > >> > > >> > Fixes: 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr") > >> > Reported-by: Jianwen Ji > >> > Signed-off-by: Xin Long > >> > --- > >> > net/sctp/ipv6.c | 27 ++++++++++++++++++++++++--- > >> > 1 file changed, 24 insertions(+), 3 deletions(-) > >> > > >> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c > >> > index f1fc48e..be4b72c 100644 > >> > --- a/net/sctp/ipv6.c > >> > +++ b/net/sctp/ipv6.c > >> > @@ -846,8 +846,8 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, > >> > const union sctp_addr *addr2, > >> > struct sctp_sock *opt) > >> > { > >> > - struct sctp_af *af1, *af2; > >> > struct sock *sk = sctp_opt2sk(opt); > >> > + struct sctp_af *af1, *af2; > >> > > >> > af1 = sctp_get_af_specific(addr1->sa.sa_family); > >> > af2 = sctp_get_af_specific(addr2->sa.sa_family); > >> > @@ -863,10 +863,31 @@ static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, > >> > if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) > >> > return 1; > >> > > >> > - if (addr1->sa.sa_family != addr2->sa.sa_family) > >> > + if (addr1->sa.sa_family != addr2->sa.sa_family) { > >> > + if (addr1->sa.sa_family = AF_INET && > >> > + addr2->sa.sa_family = AF_INET6 && > >> > + ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) > >> > + if (addr2->v6.sin6_addr.s6_addr32[3] = > >> > + addr1->v4.sin_addr.s_addr) > >> > + return 1; > >> > + if (addr2->sa.sa_family = AF_INET && > >> > + addr1->sa.sa_family = AF_INET6 && > >> > + ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) > >> > + if (addr1->v6.sin6_addr.s6_addr32[3] = > >> > + addr2->v4.sin_addr.s_addr) > >> > + return 1; > >> > + return 0; > >> > + } > >> > + > >> > + if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) > >> > + return 0; > >> > + > >> > + if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && > >> > + addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && > >> > + addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) > >> > return 0; > >> > > >> > - return af1->cmp_addr(addr1, addr2); > >> > + return 1; > >> > } > >> > > >> > /* Verify that the provided sockaddr looks bindable. Common verification, > >> > -- > >> > 2.1.0 > >> > > >> This looks correct to me, but is it worth duplicating the comparison code like > >> this from the cmp_addr function? It might be more worthwhile to add a flag to > >> the cmp_addr method to direct weather it needs to check port values or not. > >> That way you could continue to use the cmp_addr function here. > > > > Adding a flag into sctp_v6_cmp_addr will get us a terrible code to > > read. It's already not one of the best looking part of it. Maybe > > still duplicate part of it it, but at 'af' level? As in: > > - af->cmp_addr > > - af->cmp_addr_port > > > What do you think of: > > static int sctp_v6_cmp_addr(const union sctp_addr *addr1, > const union sctp_addr *addr2) > { > return __sctp_v6_cmp_addr(addr1, addr2) && > addr1->v6.sin_port = addr2->v6.sin_port; > } > > (v6.sin_port and v4.sin_port have the same offset in union sctp_addr, > we've exploited this in many places in SCTP) Yes, I'd be ok with that Neil > -- > 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 >