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sysctl(2): unlock divert{,6}_sysctl()
Introduce PR_MPSYSCTL flag to mark mp-safe (*pr_sysctl)() handlers and
unlock both divert_sysctl() and divert6_sysctl(). Unlock them together,
because they are identical and pretty simple:
- DIVERTCTL_RECVSPACE and DIVERTCTL_SENDSPACE - atomically accessed
integers;
- DIVERTCTL_STATS - per-CPU counters;
Index: sys/kern/uipc_domain.c
===================================================================
RCS file: /cvs/src/sys/kern/uipc_domain.c,v
diff -u -p -r1.67 uipc_domain.c
--- sys/kern/uipc_domain.c 14 Aug 2024 17:52:47 -0000 1.67
+++ sys/kern/uipc_domain.c 15 Aug 2024 13:21:11 -0000
@@ -237,14 +237,18 @@ net_sysctl(int *name, u_int namelen, voi
protocol = name[1];
for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
if (pr->pr_protocol == protocol && pr->pr_sysctl) {
- size_t savelen = *oldlenp;
+ size_t savelen;
int error;
- if ((error = sysctl_vslock(oldp, savelen)))
- return (error);
+ if ((pr->pr_flags & PR_MPSYSCTL) == 0) {
+ savelen = *oldlenp;
+ if ((error = sysctl_vslock(oldp, savelen)))
+ return (error);
+ }
error = (*pr->pr_sysctl)(name + 2, namelen - 2,
oldp, oldlenp, newp, newlen);
- sysctl_vsunlock(oldp, savelen);
+ if ((pr->pr_flags & PR_MPSYSCTL) == 0)
+ sysctl_vsunlock(oldp, savelen);
return (error);
}
Index: sys/netinet/in_proto.c
===================================================================
RCS file: /cvs/src/sys/netinet/in_proto.c,v
diff -u -p -r1.107 in_proto.c
--- sys/netinet/in_proto.c 26 Jul 2024 14:38:20 -0000 1.107
+++ sys/netinet/in_proto.c 15 Aug 2024 13:21:12 -0000
@@ -354,7 +354,7 @@ const struct protosw inetsw[] = {
.pr_type = SOCK_RAW,
.pr_domain = &inetdomain,
.pr_protocol = IPPROTO_DIVERT,
- .pr_flags = PR_ATOMIC|PR_ADDR|PR_MPSOCKET,
+ .pr_flags = PR_ATOMIC|PR_ADDR|PR_MPSOCKET|PR_MPSYSCTL,
.pr_ctloutput = rip_ctloutput,
.pr_usrreqs = &divert_usrreqs,
.pr_init = divert_init,
Index: sys/netinet/ip_divert.c
===================================================================
RCS file: /cvs/src/sys/netinet/ip_divert.c,v
diff -u -p -r1.96 ip_divert.c
--- sys/netinet/ip_divert.c 12 Jul 2024 19:50:35 -0000 1.96
+++ sys/netinet/ip_divert.c 15 Aug 2024 13:21:12 -0000
@@ -41,17 +41,22 @@
#include <net/pfvar.h>
+/*
+ * Locks used to protect data:
+ * a atomic
+ */
+
struct inpcbtable divbtable;
struct cpumem *divcounters;
#ifndef DIVERT_SENDSPACE
#define DIVERT_SENDSPACE (65536 + 100)
#endif
-u_int divert_sendspace = DIVERT_SENDSPACE;
+u_int divert_sendspace = DIVERT_SENDSPACE; /* [a] */
#ifndef DIVERT_RECVSPACE
#define DIVERT_RECVSPACE (65536 + 100)
#endif
-u_int divert_recvspace = DIVERT_RECVSPACE;
+u_int divert_recvspace = DIVERT_RECVSPACE; /* [a] */
#ifndef DIVERTHASHSIZE
#define DIVERTHASHSIZE 128
@@ -271,7 +276,8 @@ divert_attach(struct socket *so, int pro
if (error)
return error;
- error = soreserve(so, divert_sendspace, divert_recvspace);
+ error = soreserve(so, atomic_load_int(&divert_sendspace),
+ atomic_load_int(&divert_recvspace));
if (error)
return error;
@@ -346,8 +352,6 @@ int
divert_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
size_t newlen)
{
- int error;
-
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
@@ -356,12 +360,9 @@ divert_sysctl(int *name, u_int namelen,
case DIVERTCTL_STATS:
return (divert_sysctl_divstat(oldp, oldlenp, newp));
default:
- NET_LOCK();
- error = sysctl_bounded_arr(divertctl_vars,
- nitems(divertctl_vars), name, namelen, oldp, oldlenp, newp,
- newlen);
- NET_UNLOCK();
- return (error);
+ return (sysctl_bounded_arr(divertctl_vars,
+ nitems(divertctl_vars), name, namelen, oldp, oldlenp,
+ newp, newlen));
}
/* NOTREACHED */
}
Index: sys/netinet6/in6_proto.c
===================================================================
RCS file: /cvs/src/sys/netinet6/in6_proto.c,v
diff -u -p -r1.117 in6_proto.c
--- sys/netinet6/in6_proto.c 26 Jul 2024 14:38:20 -0000 1.117
+++ sys/netinet6/in6_proto.c 15 Aug 2024 13:21:12 -0000
@@ -289,7 +289,7 @@ const struct protosw inet6sw[] = {
.pr_type = SOCK_RAW,
.pr_domain = &inet6domain,
.pr_protocol = IPPROTO_DIVERT,
- .pr_flags = PR_ATOMIC|PR_ADDR|PR_MPSOCKET,
+ .pr_flags = PR_ATOMIC|PR_ADDR|PR_MPSOCKET|PR_MPSYSCTL,
.pr_ctloutput = rip6_ctloutput,
.pr_usrreqs = &divert6_usrreqs,
.pr_init = divert6_init,
Index: sys/netinet6/ip6_divert.c
===================================================================
RCS file: /cvs/src/sys/netinet6/ip6_divert.c,v
diff -u -p -r1.96 ip6_divert.c
--- sys/netinet6/ip6_divert.c 12 Jul 2024 19:50:35 -0000 1.96
+++ sys/netinet6/ip6_divert.c 15 Aug 2024 13:21:12 -0000
@@ -44,17 +44,22 @@
#include <net/pfvar.h>
+/*
+ * Locks used to protect data:
+ * a atomic
+ */
+
struct inpcbtable divb6table;
struct cpumem *div6counters;
#ifndef DIVERT_SENDSPACE
#define DIVERT_SENDSPACE (65536 + 100)
#endif
-u_int divert6_sendspace = DIVERT_SENDSPACE;
+u_int divert6_sendspace = DIVERT_SENDSPACE; /* [a] */
#ifndef DIVERT_RECVSPACE
#define DIVERT_RECVSPACE (65536 + 100)
#endif
-u_int divert6_recvspace = DIVERT_RECVSPACE;
+u_int divert6_recvspace = DIVERT_RECVSPACE; /* [a] */
#ifndef DIVERTHASHSIZE
#define DIVERTHASHSIZE 128
@@ -279,7 +284,8 @@ divert6_attach(struct socket *so, int pr
if (error)
return (error);
- error = soreserve(so, divert6_sendspace, divert6_recvspace);
+ error = soreserve(so, atomic_load_int(&divert6_sendspace),
+ atomic_load_int(&divert6_recvspace));
if (error)
return (error);
@@ -322,8 +328,6 @@ int
divert6_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp,
void *newp, size_t newlen)
{
- int error;
-
/* All sysctl names at this level are terminal. */
if (namelen != 1)
return (ENOTDIR);
@@ -332,12 +336,9 @@ divert6_sysctl(int *name, u_int namelen,
case DIVERT6CTL_STATS:
return (divert6_sysctl_div6stat(oldp, oldlenp, newp));
default:
- NET_LOCK();
- error = sysctl_bounded_arr(divert6ctl_vars,
+ return (sysctl_bounded_arr(divert6ctl_vars,
nitems(divert6ctl_vars), name, namelen, oldp, oldlenp,
- newp, newlen);
- NET_UNLOCK();
- return (error);
+ newp, newlen));
}
/* NOTREACHED */
}
Index: sys/sys/protosw.h
===================================================================
RCS file: /cvs/src/sys/sys/protosw.h,v
diff -u -p -r1.67 protosw.h
--- sys/sys/protosw.h 12 Jul 2024 19:50:35 -0000 1.67
+++ sys/sys/protosw.h 15 Aug 2024 13:21:12 -0000
@@ -131,6 +131,7 @@ struct protosw {
#define PR_SPLICE 0x0040 /* socket splicing is possible */
#define PR_MPINPUT 0x0080 /* input runs with shared netlock */
#define PR_MPSOCKET 0x0100 /* socket uses shared netlock */
+#define PR_MPSYSCTL 0x0200 /* mp-safe sysctl(2) handler */
/*
* The arguments to usrreq are:
sysctl(2): unlock divert{,6}_sysctl()