Provide sbsetopt() that handles socket buffer related socket options.

It distinguishes between data flow sockets and listening sockets, and
in case of the latter doesn't change resource limits, since listening
sockets don't hold any buffers, they only carry values to be inherited
by their children.

2 files changed, 76 insertions, 43 deletions

diff --git a/sys/kern/uipc_sockbuf.c b/sys/kern/uipc_sockbuf.c
index 45c69c4b14d4..51874fbbb25b 100644
--- a/sys/kern/uipc_sockbuf.c
+++ b/sys/kern/uipc_sockbuf.c
@@ -451,14 +451,78 @@ sbreserve_locked(struct sockbuf *sb, u_long cc, struct socket *so,
 }
 
 int
-sbreserve(struct sockbuf *sb, u_long cc, struct socket *so, 
-    struct thread *td)
+sbsetopt(struct socket *so, int cmd, u_long cc)
 {
+	struct sockbuf *sb;
+	short *flags;
+	u_int *hiwat, *lowat;
 	int error;
 
-	SOCKBUF_LOCK(sb);
-	error = sbreserve_locked(sb, cc, so, td);
-	SOCKBUF_UNLOCK(sb);
+	SOCK_LOCK(so);
+	if (SOLISTENING(so)) {
+		switch (cmd) {
+			case SO_SNDLOWAT:
+			case SO_SNDBUF:
+				lowat = &so->sol_sbsnd_lowat;
+				hiwat = &so->sol_sbsnd_hiwat;
+				flags = &so->sol_sbsnd_flags;
+				break;
+			case SO_RCVLOWAT:
+			case SO_RCVBUF:
+				lowat = &so->sol_sbrcv_lowat;
+				hiwat = &so->sol_sbrcv_hiwat;
+				flags = &so->sol_sbrcv_flags;
+				break;
+		}
+	} else {
+		switch (cmd) {
+			case SO_SNDLOWAT:
+			case SO_SNDBUF:
+				sb = &so->so_snd;
+				break;
+			case SO_RCVLOWAT:
+			case SO_RCVBUF:
+				sb = &so->so_rcv;
+				break;
+		}
+		flags = &sb->sb_flags;
+		hiwat = &sb->sb_hiwat;
+		lowat = &sb->sb_lowat;
+		SOCKBUF_LOCK(sb);
+	}
+
+	error = 0;
+	switch (cmd) {
+	case SO_SNDBUF:
+	case SO_RCVBUF:
+		if (SOLISTENING(so)) {
+			if (cc > sb_max_adj) {
+				error = ENOBUFS;
+				break;
+			}
+			*hiwat = cc;
+			if (*lowat > *hiwat)
+				*lowat = *hiwat;
+		} else {
+			if (!sbreserve_locked(sb, cc, so, curthread))
+				error = ENOBUFS;
+		}
+		if (error == 0)
+			*flags &= ~SB_AUTOSIZE;
+		break;
+	case SO_SNDLOWAT:
+	case SO_RCVLOWAT:
+		/*
+		 * Make sure the low-water is never greater than the
+		 * high-water.
+		 */
+		*lowat = (cc > *hiwat) ? *hiwat : cc;
+		break;
+	}
+
+	if (!SOLISTENING(so))
+		SOCKBUF_UNLOCK(sb);
+	SOCK_UNLOCK(so);
 	return (error);
 }
 
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 55f5cdcd6801..129a0a2842b2 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -461,12 +461,6 @@ sodealloc(struct socket *so)
 	so->so_vnet->vnet_sockcnt--;
 #endif
 	mtx_unlock(&so_global_mtx);
-	if (so->so_rcv.sb_hiwat)
-		(void)chgsbsize(so->so_cred->cr_uidinfo,
-		    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
-	if (so->so_snd.sb_hiwat)
-		(void)chgsbsize(so->so_cred->cr_uidinfo,
-		    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
 #ifdef MAC
 	mac_socket_destroy(so);
 #endif
@@ -478,6 +472,12 @@ sodealloc(struct socket *so)
 		if (so->sol_accept_filter != NULL)
 			accept_filt_setopt(so, NULL);
 	} else {
+		if (so->so_rcv.sb_hiwat)
+			(void)chgsbsize(so->so_cred->cr_uidinfo,
+			    &so->so_rcv.sb_hiwat, 0, RLIM_INFINITY);
+		if (so->so_snd.sb_hiwat)
+			(void)chgsbsize(so->so_cred->cr_uidinfo,
+			    &so->so_snd.sb_hiwat, 0, RLIM_INFINITY);
 		sx_destroy(&so->so_snd.sb_sx);
 		sx_destroy(&so->so_rcv.sb_sx);
 		SOCKBUF_LOCK_DESTROY(&so->so_snd);
@@ -2834,38 +2834,7 @@ sosetopt(struct socket *so, struct sockopt *sopt)
 				goto bad;
 			}
 
-			switch (sopt->sopt_name) {
-			case SO_SNDBUF:
-			case SO_RCVBUF:
-				if (sbreserve(sopt->sopt_name == SO_SNDBUF ?
-				    &so->so_snd : &so->so_rcv, (u_long)optval,
-				    so, curthread) == 0) {
-					error = ENOBUFS;
-					goto bad;
-				}
-				(sopt->sopt_name == SO_SNDBUF ? &so->so_snd :
-				    &so->so_rcv)->sb_flags &= ~SB_AUTOSIZE;
-				break;
-
-			/*
-			 * Make sure the low-water is never greater than the
-			 * high-water.
-			 */
-			case SO_SNDLOWAT:
-				SOCKBUF_LOCK(&so->so_snd);
-				so->so_snd.sb_lowat =
-				    (optval > so->so_snd.sb_hiwat) ?
-				    so->so_snd.sb_hiwat : optval;
-				SOCKBUF_UNLOCK(&so->so_snd);
-				break;
-			case SO_RCVLOWAT:
-				SOCKBUF_LOCK(&so->so_rcv);
-				so->so_rcv.sb_lowat =
-				    (optval > so->so_rcv.sb_hiwat) ?
-				    so->so_rcv.sb_hiwat : optval;
-				SOCKBUF_UNLOCK(&so->so_rcv);
-				break;
-			}
+			error = sbsetopt(so, sopt->sopt_name, optval);
 			break;
 
 		case SO_SNDTIMEO: