sctp: add SCTP_PEER_ADDR_THLDS_V2 sockopt

Section 7.2 of rfc7829: "Peer Address Thresholds (SCTP_PEER_ADDR_THLDS)
Socket Option" extends 'struct sctp_paddrthlds' with 'spt_pathcpthld'
added to allow a user to change ps_retrans per sock/asoc/transport, as
other 2 paddrthlds: pf_retrans, pathmaxrxt.

Note: to not break the user's program, here to support pf_retrans dump
and setting by adding a new sockopt SCTP_PEER_ADDR_THLDS_V2, and a new
structure sctp_paddrthlds_v2 instead of extending sctp_paddrthlds.

Also, when setting ps_retrans, the value is not allowed to be greater
than pf_retrans.

v1->v2:
  - use SCTP_PEER_ADDR_THLDS_V2 to set/get pf_retrans instead,
    as Marcelo and David Laight suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index a190e4a..28ad40d 100644 (file)
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -105,6 +105,7 @@ typedef __s32 sctp_assoc_t;
 #define SCTP_DEFAULT_SNDINFO   34
 #define SCTP_AUTH_DEACTIVATE_KEY       35
 #define SCTP_REUSE_PORT                36
+#define SCTP_PEER_ADDR_THLDS_V2        37
 
 /* Internal Socket Options. Some of the sctp library functions are
  * implemented using these socket options.
@@ -1087,6 +1088,15 @@ struct sctp_paddrthlds {
        __u16 spt_pathpfthld;
 };
 
+/* Use a new structure with spt_pathcpthld for back compatibility */
+struct sctp_paddrthlds_v2 {
+       sctp_assoc_t spt_assoc_id;
+       struct sockaddr_storage spt_address;
+       __u16 spt_pathmaxrxt;
+       __u16 spt_pathpfthld;
+       __u16 spt_pathcpthld;
+};
+
 /*
  * Socket Option for Getting the Association/Stream-Specific PR-SCTP Status
  */

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 64452ee..83e4ca1 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3943,18 +3943,22 @@ static int sctp_setsockopt_auto_asconf(struct sock *sk, char __user *optval,
  */
 static int sctp_setsockopt_paddr_thresholds(struct sock *sk,
                                            char __user *optval,
-                                           unsigned int optlen)
+                                           unsigned int optlen, bool v2)
 {
-       struct sctp_paddrthlds val;
+       struct sctp_paddrthlds_v2 val;
        struct sctp_transport *trans;
        struct sctp_association *asoc;
+       int len;
 
-       if (optlen < sizeof(struct sctp_paddrthlds))
+       len = v2 ? sizeof(val) : sizeof(struct sctp_paddrthlds);
+       if (optlen < len)
                return -EINVAL;
-       if (copy_from_user(&val, (struct sctp_paddrthlds __user *)optval,
-                          sizeof(struct sctp_paddrthlds)))
+       if (copy_from_user(&val, optval, len))
                return -EFAULT;
 
+       if (v2 && val.spt_pathpfthld > val.spt_pathcpthld)
+               return -EINVAL;
+
        if (!sctp_is_any(sk, (const union sctp_addr *)&val.spt_address)) {
                trans = sctp_addr_id2transport(sk, &val.spt_address,
                                               val.spt_assoc_id);
@@ -3963,6 +3967,8 @@ static int sctp_setsockopt_paddr_thresholds(struct sock *sk,
 
                if (val.spt_pathmaxrxt)
                        trans->pathmaxrxt = val.spt_pathmaxrxt;
+               if (v2)
+                       trans->ps_retrans = val.spt_pathcpthld;
                trans->pf_retrans = val.spt_pathpfthld;
 
                return 0;
@@ -3978,17 +3984,23 @@ static int sctp_setsockopt_paddr_thresholds(struct sock *sk,
                                    transports) {
                        if (val.spt_pathmaxrxt)
                                trans->pathmaxrxt = val.spt_pathmaxrxt;
+                       if (v2)
+                               trans->ps_retrans = val.spt_pathcpthld;
                        trans->pf_retrans = val.spt_pathpfthld;
                }
 
                if (val.spt_pathmaxrxt)
                        asoc->pathmaxrxt = val.spt_pathmaxrxt;
+               if (v2)
+                       asoc->ps_retrans = val.spt_pathcpthld;
                asoc->pf_retrans = val.spt_pathpfthld;
        } else {
                struct sctp_sock *sp = sctp_sk(sk);
 
                if (val.spt_pathmaxrxt)
                        sp->pathmaxrxt = val.spt_pathmaxrxt;
+               if (v2)
+                       sp->ps_retrans = val.spt_pathcpthld;
                sp->pf_retrans = val.spt_pathpfthld;
        }
 
@@ -4778,7 +4790,12 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname,
                retval = sctp_setsockopt_auto_asconf(sk, optval, optlen);
                break;
        case SCTP_PEER_ADDR_THLDS:
-               retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen);
+               retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen,
+                                                         false);
+               break;
+       case SCTP_PEER_ADDR_THLDS_V2:
+               retval = sctp_setsockopt_paddr_thresholds(sk, optval, optlen,
+                                                         true);
                break;
        case SCTP_RECVRCVINFO:
                retval = sctp_setsockopt_recvrcvinfo(sk, optval, optlen);
@@ -7217,18 +7234,19 @@ static int sctp_getsockopt_assoc_ids(struct sock *sk, int len,
  * http://www.ietf.org/id/draft-nishida-tsvwg-sctp-failover-05.txt
  */
 static int sctp_getsockopt_paddr_thresholds(struct sock *sk,
-                                           char __user *optval,
-                                           int len,
-                                           int __user *optlen)
+                                           char __user *optval, int len,
+                                           int __user *optlen, bool v2)
 {
-       struct sctp_paddrthlds val;
+       struct sctp_paddrthlds_v2 val;
        struct sctp_transport *trans;
        struct sctp_association *asoc;
+       int min;
 
-       if (len < sizeof(struct sctp_paddrthlds))
+       min = v2 ? sizeof(val) : sizeof(struct sctp_paddrthlds);
+       if (len < min)
                return -EINVAL;
-       len = sizeof(struct sctp_paddrthlds);
-       if (copy_from_user(&val, (struct sctp_paddrthlds __user *)optval, len))
+       len = min;
+       if (copy_from_user(&val, optval, len))
                return -EFAULT;
 
        if (!sctp_is_any(sk, (const union sctp_addr *)&val.spt_address)) {
@@ -7239,6 +7257,7 @@ static int sctp_getsockopt_paddr_thresholds(struct sock *sk,
 
                val.spt_pathmaxrxt = trans->pathmaxrxt;
                val.spt_pathpfthld = trans->pf_retrans;
+               val.spt_pathcpthld = trans->ps_retrans;
 
                goto out;
        }
@@ -7251,11 +7270,13 @@ static int sctp_getsockopt_paddr_thresholds(struct sock *sk,
        if (asoc) {
                val.spt_pathpfthld = asoc->pf_retrans;
                val.spt_pathmaxrxt = asoc->pathmaxrxt;
+               val.spt_pathcpthld = asoc->ps_retrans;
        } else {
                struct sctp_sock *sp = sctp_sk(sk);
 
                val.spt_pathpfthld = sp->pf_retrans;
                val.spt_pathmaxrxt = sp->pathmaxrxt;
+               val.spt_pathcpthld = sp->ps_retrans;
        }
 
 out:
@@ -8135,7 +8156,12 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname,
                retval = sctp_getsockopt_auto_asconf(sk, len, optval, optlen);
                break;
        case SCTP_PEER_ADDR_THLDS:
-               retval = sctp_getsockopt_paddr_thresholds(sk, optval, len, optlen);
+               retval = sctp_getsockopt_paddr_thresholds(sk, optval, len,
+                                                         optlen, false);
+               break;
+       case SCTP_PEER_ADDR_THLDS_V2:
+               retval = sctp_getsockopt_paddr_thresholds(sk, optval, len,
+                                                         optlen, true);
                break;
        case SCTP_GET_ASSOC_STATS:
                retval = sctp_getsockopt_assoc_stats(sk, len, optval, optlen);