Merge from projects/sendfile:

o Introduce a notion of "not ready" mbufs in socket buffers.  These
mbufs are now being populated by some I/O in background and are
referenced outside.  This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
  freed.

o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
  The sb_ccc stands for ""claimed character count", or "committed
  character count".  And the sb_acc is "available character count".
  Consumers of socket buffer API shouldn't already access them directly,
  but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
  with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
  search.
o New function sbready() is provided to activate certain amount of mbufs
  in a socket buffer.

A special note on SCTP:
  SCTP has its own sockbufs.  Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs.  Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them.  The new
notion of "not ready" data isn't supported by SCTP.  Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
  A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does.  This was discussed with rrs@.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.

3 files changed, 6 insertions, 4 deletions

diff --git a/usr.bin/netstat/inet.c b/usr.bin/netstat/inet.c
index 10d0698..c22e49f 100644
--- a/usr.bin/netstat/inet.c
+++ b/usr.bin/netstat/inet.c
@@ -137,7 +137,7 @@ pcblist_sysctl(int proto, const char *name, char **bufp, int istcp __unused)
 static void
 sbtoxsockbuf(struct sockbuf *sb, struct xsockbuf *xsb)
 {
-	xsb->sb_cc = sb->sb_cc;
+	xsb->sb_cc = sb->sb_ccc;
 	xsb->sb_hiwat = sb->sb_hiwat;
 	xsb->sb_mbcnt = sb->sb_mbcnt;
 	xsb->sb_mcnt = sb->sb_mcnt;
@@ -479,7 +479,8 @@ protopr(u_long off, const char *name, int af1, int proto)
 				printf("%6u %6u %6u ", tp->t_sndrexmitpack,
 				       tp->t_rcvoopack, tp->t_sndzerowin);
 		} else {
-			printf("%6u %6u ", so->so_rcv.sb_cc, so->so_snd.sb_cc);
+			printf("%6u %6u ",
+			    so->so_rcv.sb_cc, so->so_snd.sb_cc);
 		}
 		if (numeric_port) {
 			if (inp->inp_vflag & INP_IPV4) {
diff --git a/usr.bin/netstat/netgraph.c b/usr.bin/netstat/netgraph.c
index 95578af..9a08b6d 100644
--- a/usr.bin/netstat/netgraph.c
+++ b/usr.bin/netstat/netgraph.c
@@ -119,7 +119,7 @@ netgraphprotopr(u_long off, const char *name, int af1 __unused,
 		if (Aflag)
 			printf("%8lx ", (u_long) this);
 		printf("%-5.5s %6u %6u ",
-		    name, sockb.so_rcv.sb_cc, sockb.so_snd.sb_cc);
+		    name, sockb.so_rcv.sb_ccc, sockb.so_snd.sb_ccc);
 
 		/* Get info on associated node */
 		if (ngpcb.node_id == 0 || csock == -1)
diff --git a/usr.bin/netstat/unix.c b/usr.bin/netstat/unix.c
index 027e812..a5cc037 100644
--- a/usr.bin/netstat/unix.c
+++ b/usr.bin/netstat/unix.c
@@ -287,7 +287,8 @@ unixdomainpr(struct xunpcb *xunp, struct xsocket *so)
 	} else {
 		printf("%8lx %-6.6s %6u %6u %8lx %8lx %8lx %8lx",
 		    (long)so->so_pcb, socktype[so->so_type], so->so_rcv.sb_cc,
-		    so->so_snd.sb_cc, (long)unp->unp_vnode, (long)unp->unp_conn,
+		    so->so_snd.sb_cc, (long)unp->unp_vnode,
+		    (long)unp->unp_conn,
 		    (long)LIST_FIRST(&unp->unp_refs),
 		    (long)LIST_NEXT(unp, unp_reflink));
 	}