Fix race conditions on enumerating pcb lists by moving the initialization

( and where appropriate the destruction) of the pcb mutex to the init/finit
functions of the pcb zones.
This allows locking of the pcb entries and race condition free comparison
of the generation count.
Rearrange locking a bit to avoid extra locking operation to update the generation
count in in_pcballoc(). (in_pcballoc now returns the pcb locked)

I am planning to convert pcb list handling from a type safe to a reference count
model soon. ( As this allows really freeing the PCBs)

Reviewed by:	rwatson@, mohans@
MFC after:	1 week

1 files changed, 2 insertions, 1 deletions

diff --git a/sys/netinet/in_pcb.h b/sys/netinet/in_pcb.h
index 80ae9e9..64de94b 100644
--- a/sys/netinet/in_pcb.h
+++ b/sys/netinet/in_pcb.h
@@ -166,6 +166,7 @@ struct inpcb {
 	} inp_depend6;
 	LIST_ENTRY(inpcb) inp_portlist;
 	struct	inpcbport *inp_phd;	/* head of this list */
+#define inp_zero_size offsetof(struct inpcb, inp_gencnt)
 	inp_gen_t	inp_gencnt;	/* generation count of this instance */
 	struct mtx	inp_mtx;
 
@@ -342,7 +343,7 @@ extern int	ipport_hilastauto;
 extern struct callout ipport_tick_callout;
 
 void	in_pcbpurgeif0(struct inpcbinfo *, struct ifnet *);
-int	in_pcballoc(struct socket *, struct inpcbinfo *, const char *);
+int	in_pcballoc(struct socket *, struct inpcbinfo *);
 int	in_pcbbind(struct inpcb *, struct sockaddr *, struct ucred *);
 int	in_pcbbind_setup(struct inpcb *, struct sockaddr *, in_addr_t *,
 	    u_short *, struct ucred *);