sctp: add support for PR-SCTP Information for sendmsg

This patch is to add support for PR-SCTP Information for sendmsg,
as described in section 5.3.7 of RFC6458.

With this option, you can specify pr_policy and pr_value for user
data in sendmsg.

It's also a necessary send info for sctp_sendv.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 03e92dda1813bc262d58c5a0866399d45676b2c9..d40a2a329888e8646bd156c4c69712d0c46f4967 100644 (file)
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -2112,6 +2112,7 @@ struct sctp_cmsgs {
        struct sctp_initmsg *init;
        struct sctp_sndrcvinfo *srinfo;
        struct sctp_sndinfo *sinfo;
+       struct sctp_prinfo *prinfo;
 };
 
 /* Structure for tracking memory objects */

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index 4c4db14786bd04360e1b44a7e23275d7bb9f882d..0dd1f82a4fa8922522f8be0d83ab218f4295eb6c 100644 (file)
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h
@@ -260,6 +260,19 @@ struct sctp_nxtinfo {
        sctp_assoc_t nxt_assoc_id;
 };
 
+/* 5.3.7 SCTP PR-SCTP Information Structure (SCTP_PRINFO)
+ *
+ *   This cmsghdr structure specifies SCTP options for sendmsg().
+ *
+ *   cmsg_level    cmsg_type      cmsg_data[]
+ *   ------------  ------------   -------------------
+ *   IPPROTO_SCTP  SCTP_PRINFO    struct sctp_prinfo
+ */
+struct sctp_prinfo {
+       __u16 pr_policy;
+       __u32 pr_value;
+};
+
 /*
  *  sinfo_flags: 16 bits (unsigned integer)
  *
@@ -293,6 +306,8 @@ typedef enum sctp_cmsg_type {
 #define SCTP_RCVINFO   SCTP_RCVINFO
        SCTP_NXTINFO,           /* 5.3.6 SCTP Next Receive Information Structure */
 #define SCTP_NXTINFO   SCTP_NXTINFO
+       SCTP_PRINFO,            /* 5.3.7 SCTP PR-SCTP Information Structure */
+#define SCTP_PRINFO    SCTP_PRINFO
 } sctp_cmsg_t;
 
 /*

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 7fa76031bb08623155de2c82d1b0ac5de0729ac8..fdde697b37e735d7fa6acb24ed4260f93c86a50d 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1644,6 +1644,12 @@ static int sctp_sendmsg_parse(struct sock *sk, struct sctp_cmsgs *cmsgs,
                srinfo->sinfo_assoc_id = cmsgs->sinfo->snd_assoc_id;
        }
 
+       if (cmsgs->prinfo) {
+               srinfo->sinfo_timetolive = cmsgs->prinfo->pr_value;
+               SCTP_PR_SET_POLICY(srinfo->sinfo_flags,
+                                  cmsgs->prinfo->pr_policy);
+       }
+
        sflags = srinfo->sinfo_flags;
        if (!sflags && msg_len)
                return 0;
@@ -1901,9 +1907,12 @@ static void sctp_sendmsg_update_sinfo(struct sctp_association *asoc,
                sinfo->sinfo_ppid = asoc->default_ppid;
                sinfo->sinfo_context = asoc->default_context;
                sinfo->sinfo_assoc_id = sctp_assoc2id(asoc);
+
+               if (!cmsgs->prinfo)
+                       sinfo->sinfo_flags = asoc->default_flags;
        }
 
-       if (!cmsgs->srinfo)
+       if (!cmsgs->srinfo && !cmsgs->prinfo)
                sinfo->sinfo_timetolive = asoc->default_timetolive;
 }
 
@@ -7749,6 +7758,26 @@ static int sctp_msghdr_parse(const struct msghdr *msg, struct sctp_cmsgs *cmsgs)
                              SCTP_ABORT | SCTP_EOF))
                                return -EINVAL;
                        break;
+               case SCTP_PRINFO:
+                       /* SCTP Socket API Extension
+                        * 5.3.7 SCTP PR-SCTP Information Structure (SCTP_PRINFO)
+                        *
+                        * This cmsghdr structure specifies SCTP options for sendmsg().
+                        *
+                        * cmsg_level    cmsg_type      cmsg_data[]
+                        * ------------  ------------   ---------------------
+                        * IPPROTO_SCTP  SCTP_PRINFO    struct sctp_prinfo
+                        */
+                       if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct sctp_prinfo)))
+                               return -EINVAL;
+
+                       cmsgs->prinfo = CMSG_DATA(cmsg);
+                       if (cmsgs->prinfo->pr_policy & ~SCTP_PR_SCTP_MASK)
+                               return -EINVAL;
+
+                       if (cmsgs->prinfo->pr_policy == SCTP_PR_SCTP_NONE)
+                               cmsgs->prinfo->pr_value = 0;
+                       break;
                default:
                        return -EINVAL;
                }