diff options
author | ups <ups@FreeBSD.org> | 2006-07-18 22:34:27 +0000 |
---|---|---|
committer | ups <ups@FreeBSD.org> | 2006-07-18 22:34:27 +0000 |
commit | ee0a5eb928ae5ccdf1a0e619b4ba6e93d19db5fb (patch) | |
tree | 2e39fd9d815a6efa63bdabd6bfed00c38e05310a /sys/netinet/tcp_subr.c | |
parent | 9adb8df4815a901cfc690d567d4ba0b6c63b1d5d (diff) | |
download | FreeBSD-src-ee0a5eb928ae5ccdf1a0e619b4ba6e93d19db5fb.zip FreeBSD-src-ee0a5eb928ae5ccdf1a0e619b4ba6e93d19db5fb.tar.gz |
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
Diffstat (limited to 'sys/netinet/tcp_subr.c')
-rw-r--r-- | sys/netinet/tcp_subr.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c index 89bd41c..676b22e 100644 --- a/sys/netinet/tcp_subr.c +++ b/sys/netinet/tcp_subr.c @@ -262,6 +262,14 @@ tcp_zone_change(void *tag) uma_zone_set_max(tcptw_zone, maxsockets / 5); } +static int +tcp_inpcb_init(void *mem, int size, int flags) +{ + struct inpcb *inp = (struct inpcb *) mem; + INP_LOCK_INIT(inp, "inp", "tcpinp"); + return (0); +} + void tcp_init(void) { @@ -290,7 +298,7 @@ tcp_init(void) tcbinfo.porthashbase = hashinit(hashsize, M_PCB, &tcbinfo.porthashmask); tcbinfo.ipi_zone = uma_zcreate("inpcb", sizeof(struct inpcb), - NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); + NULL, NULL, tcp_inpcb_init, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); uma_zone_set_max(tcbinfo.ipi_zone, maxsockets); #ifdef INET6 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) @@ -989,6 +997,7 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS) error = 0; for (i = 0; i < n; i++) { inp = inp_list[i]; + INP_LOCK(inp); if (inp->inp_gencnt <= gencnt) { struct xtcpcb xt; void *inp_ppcb; @@ -1012,8 +1021,11 @@ tcp_pcblist(SYSCTL_HANDLER_ARGS) xt.xt_socket.xso_protocol = IPPROTO_TCP; } xt.xt_inp.inp_gencnt = inp->inp_gencnt; + INP_UNLOCK(inp); error = SYSCTL_OUT(req, &xt, sizeof xt); - } + } else + INP_UNLOCK(inp); + } if (!error) { /* |