Commit 204f817f authored by Xin Long's avatar Xin Long Committed by David S. Miller
Browse files

sctp: factor out sctp_sendmsg_parse from sctp_sendmsg 



This patch is to move the codes for parsing msghdr and checking
sk into sctp_sendmsg_parse.

Note that different from before, 'sinfo' in sctp_sendmsg won't
be NULL any more. It gets the value either from cmsgs->srinfo,
cmsgs->sinfo or asoc. With it, the 'sinfo' and 'fill_sinfo_ttl'
check can be removed from sctp_sendmsg.

Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent becef9b1

net/sctp/socket.c

+69 −103
Original line number Diff line number Diff line
@@ -1606,6 +1606,61 @@ static int sctp_error(struct sock *sk, int flags, int err) 
static int sctp_msghdr_parse(const struct msghdr *msg,

			     struct sctp_cmsgs *cmsgs);



static int sctp_sendmsg_parse(struct sock *sk, struct sctp_cmsgs *cmsgs,

			      struct sctp_sndrcvinfo *srinfo,

			      const struct msghdr *msg, size_t msg_len)

{

	__u16 sflags;

	int err;



	if (sctp_sstate(sk, LISTENING) && sctp_style(sk, TCP))

		return -EPIPE;



	if (msg_len > sk->sk_sndbuf)

		return -EMSGSIZE;



	memset(cmsgs, 0, sizeof(*cmsgs));

	err = sctp_msghdr_parse(msg, cmsgs);

	if (err) {

		pr_debug("%s: msghdr parse err:%x\n", __func__, err);

		return err;

	}



	memset(srinfo, 0, sizeof(*srinfo));

	if (cmsgs->srinfo) {

		srinfo->sinfo_stream = cmsgs->srinfo->sinfo_stream;

		srinfo->sinfo_flags = cmsgs->srinfo->sinfo_flags;

		srinfo->sinfo_ppid = cmsgs->srinfo->sinfo_ppid;

		srinfo->sinfo_context = cmsgs->srinfo->sinfo_context;

		srinfo->sinfo_assoc_id = cmsgs->srinfo->sinfo_assoc_id;

		srinfo->sinfo_timetolive = cmsgs->srinfo->sinfo_timetolive;

	}



	if (cmsgs->sinfo) {

		srinfo->sinfo_stream = cmsgs->sinfo->snd_sid;

		srinfo->sinfo_flags = cmsgs->sinfo->snd_flags;

		srinfo->sinfo_ppid = cmsgs->sinfo->snd_ppid;

		srinfo->sinfo_context = cmsgs->sinfo->snd_context;

		srinfo->sinfo_assoc_id = cmsgs->sinfo->snd_assoc_id;

	}



	sflags = srinfo->sinfo_flags;

	if (!sflags && msg_len)

		return 0;



	if (sctp_style(sk, TCP) && (sflags & (SCTP_EOF | SCTP_ABORT)))

		return -EINVAL;



	if (((sflags & SCTP_EOF) && msg_len > 0) ||

	    (!(sflags & (SCTP_EOF | SCTP_ABORT)) && msg_len == 0))

		return -EINVAL;



	if ((sflags & SCTP_ADDR_OVER) && !msg->msg_name)

		return -EINVAL;



	return 0;

}



static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,

				 struct sctp_cmsgs *cmsgs,

				 union sctp_addr *daddr,
@@ -1839,39 +1894,23 @@ static union sctp_addr *sctp_sendmsg_get_daddr(struct sock *sk, 


static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)

{

	struct sctp_sock *sp;

	struct sctp_endpoint *ep;

	struct sctp_endpoint *ep = sctp_sk(sk)->ep;

	struct sctp_association *new_asoc = NULL, *asoc = NULL;

	struct sctp_transport *transport, *chunk_tp;

	struct sctp_sndrcvinfo default_sinfo;

	struct sctp_sndrcvinfo *sinfo;

	struct sctp_initmsg *sinit;

	struct sctp_sndrcvinfo _sinfo, *sinfo;

	sctp_assoc_t associd = 0;

	struct sctp_cmsgs cmsgs = { NULL };

	bool fill_sinfo_ttl = false;

	__u16 sinfo_flags = 0;

	union sctp_addr *daddr;

	int err;



	err = 0;

	sp = sctp_sk(sk);

	ep = sp->ep;



	pr_debug("%s: sk:%p, msg:%p, msg_len:%zu ep:%p\n", __func__, sk,

		 msg, msg_len, ep);



	/* We cannot send a message over a TCP-style listening socket. */

	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) {

		err = -EPIPE;

	/* Parse and get snd_info */

	err = sctp_sendmsg_parse(sk, &cmsgs, &_sinfo, msg, msg_len);

	if (err)

		goto out_nounlock;

	}



	/* Parse out the SCTP CMSGs.  */

	err = sctp_msghdr_parse(msg, &cmsgs);

	if (err) {

		pr_debug("%s: msghdr parse err:%x\n", __func__, err);

		goto out_nounlock;

	}

	sinfo  = &_sinfo;

	sinfo_flags = sinfo->sinfo_flags;



	/* Get daddr from msg */

	daddr = sctp_sendmsg_get_daddr(sk, msg, &cmsgs);
@@ -1880,58 +1919,6 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) 
		goto out_nounlock;

	}



	sinit = cmsgs.init;

	if (cmsgs.sinfo != NULL) {

		memset(&default_sinfo, 0, sizeof(default_sinfo));

		default_sinfo.sinfo_stream = cmsgs.sinfo->snd_sid;

		default_sinfo.sinfo_flags = cmsgs.sinfo->snd_flags;

		default_sinfo.sinfo_ppid = cmsgs.sinfo->snd_ppid;

		default_sinfo.sinfo_context = cmsgs.sinfo->snd_context;

		default_sinfo.sinfo_assoc_id = cmsgs.sinfo->snd_assoc_id;



		sinfo = &default_sinfo;

		fill_sinfo_ttl = true;

	} else {

		sinfo = cmsgs.srinfo;

	}

	/* Did the user specify SNDINFO/SNDRCVINFO? */

	if (sinfo) {

		sinfo_flags = sinfo->sinfo_flags;

		associd = sinfo->sinfo_assoc_id;

	}



	pr_debug("%s: msg_len:%zu, sinfo_flags:0x%x\n", __func__,

		 msg_len, sinfo_flags);



	/* SCTP_EOF or SCTP_ABORT cannot be set on a TCP-style socket. */

	if (sctp_style(sk, TCP) && (sinfo_flags & (SCTP_EOF | SCTP_ABORT))) {

		err = -EINVAL;

		goto out_nounlock;

	}



	/* If SCTP_EOF is set, no data can be sent. Disallow sending zero

	 * length messages when SCTP_EOF|SCTP_ABORT is not set.

	 * If SCTP_ABORT is set, the message length could be non zero with

	 * the msg_iov set to the user abort reason.

	 */

	if (((sinfo_flags & SCTP_EOF) && (msg_len > 0)) ||

	    (!(sinfo_flags & (SCTP_EOF|SCTP_ABORT)) && (msg_len == 0))) {

		err = -EINVAL;

		goto out_nounlock;

	}



	/* If SCTP_ADDR_OVER is set, there must be an address

	 * specified in msg_name.

	 */

	if ((sinfo_flags & SCTP_ADDR_OVER) && (!msg->msg_name)) {

		err = -EINVAL;

		goto out_nounlock;

	}



	transport = NULL;



	pr_debug("%s: about to look up association\n", __func__);



	lock_sock(sk);



	/* If a msg_name has been specified, assume this is to be used.  */
@@ -1964,36 +1951,15 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len) 
		new_asoc = asoc;

	}



	/* ASSERT: we have a valid association at this point.  */

	pr_debug("%s: we have a valid association\n", __func__);



	if (!sinfo) {

		/* If the user didn't specify SNDINFO/SNDRCVINFO, make up

		 * one with some defaults.

		 */

		memset(&default_sinfo, 0, sizeof(default_sinfo));

		default_sinfo.sinfo_stream = asoc->default_stream;

		default_sinfo.sinfo_flags = asoc->default_flags;

		default_sinfo.sinfo_ppid = asoc->default_ppid;

		default_sinfo.sinfo_context = asoc->default_context;

		default_sinfo.sinfo_timetolive = asoc->default_timetolive;

		default_sinfo.sinfo_assoc_id = sctp_assoc2id(asoc);



		sinfo = &default_sinfo;

	} else if (fill_sinfo_ttl) {

		/* In case SNDINFO was specified, we still need to fill

		 * it with a default ttl from the assoc here.

		 */

		sinfo->sinfo_timetolive = asoc->default_timetolive;

	if (!cmsgs.srinfo && !cmsgs.sinfo) {

		sinfo->sinfo_stream = asoc->default_stream;

		sinfo->sinfo_ppid = asoc->default_ppid;

		sinfo->sinfo_context = asoc->default_context;

		sinfo->sinfo_assoc_id = sctp_assoc2id(asoc);

	}



	/* API 7.1.7, the sndbuf size per association bounds the

	 * maximum size of data that can be sent in a single send call.

	 */

	if (msg_len > sk->sk_sndbuf) {

		err = -EMSGSIZE;

		goto out_free;

	}

	if (!cmsgs.srinfo)

		sinfo->sinfo_timetolive = asoc->default_timetolive;



	/* If an address is passed with the sendto/sendmsg call, it is used

	 * to override the primary destination address in the TCP model, or

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