From 133935d26f20c0b9c433da9a2b32bcbe562bc2c5 Mon Sep 17 00:00:00 2001 From: Kristof Provost Date: Fri, 7 Oct 2022 19:17:06 +0200 Subject: [PATCH] pf: atomically increment state ids Rather than using a per-cpu state counter, and adding in the CPU id we can atomically increment the number. This has the advantage of removing the assumption that the CPU ID fits in 8 bits. Event: Aberdeen Hackathon 2022 Reviewed by: mjg Differential Revision: https://reviews.freebsd.org/D36915 --- sys/net/pfvar.h | 2 +- sys/netpfil/pf/pf.c | 12 ++---------- sys/netpfil/pf/pf_ioctl.c | 6 +----- 3 files changed, 4 insertions(+), 16 deletions(-) diff --git a/sys/net/pfvar.h b/sys/net/pfvar.h index 16ee0b55e2e8..3773a797776d 100644 --- a/sys/net/pfvar.h +++ b/sys/net/pfvar.h @@ -1987,7 +1987,7 @@ VNET_DECLARE(void *, pf_swi_cookie); VNET_DECLARE(struct intr_event *, pf_swi_ie); #define V_pf_swi_ie VNET(pf_swi_ie) -VNET_DECLARE(uint64_t, pf_stateid[MAXCPU]); +VNET_DECLARE(struct unrhdr64, pf_stateid); #define V_pf_stateid VNET(pf_stateid) TAILQ_HEAD(pf_altqqueue, pf_altq); diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c index 33ef5119ee3c..2a6efbfe6e7d 100644 --- a/sys/netpfil/pf/pf.c +++ b/sys/netpfil/pf/pf.c @@ -249,12 +249,7 @@ uma_zone_t pf_mtag_z; VNET_DEFINE(uma_zone_t, pf_state_z); VNET_DEFINE(uma_zone_t, pf_state_key_z); -VNET_DEFINE(uint64_t, pf_stateid[MAXCPU]); -#define PFID_CPUBITS 8 -#define PFID_CPUSHIFT (sizeof(uint64_t) * NBBY - PFID_CPUBITS) -#define PFID_CPUMASK ((uint64_t)((1 << PFID_CPUBITS) - 1) << PFID_CPUSHIFT) -#define PFID_MAXID (~PFID_CPUMASK) -CTASSERT((1 << PFID_CPUBITS) >= MAXCPU); +VNET_DEFINE(struct unrhdr64, pf_stateid); static void pf_src_tree_remove_state(struct pf_kstate *); static void pf_init_threshold(struct pf_threshold *, u_int32_t, @@ -1416,10 +1411,7 @@ pf_state_insert(struct pfi_kkif *kif, struct pfi_kkif *orig_kif, s->orig_kif = orig_kif; if (s->id == 0 && s->creatorid == 0) { - /* XXX: should be atomic, but probability of collision low */ - if ((s->id = V_pf_stateid[curcpu]++) == PFID_MAXID) - V_pf_stateid[curcpu] = 1; - s->id |= (uint64_t )curcpu << PFID_CPUSHIFT; + s->id = alloc_unr64(&V_pf_stateid); s->id = htobe64(s->id); s->creatorid = V_pf_status.hostid; } diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c index 67422cc43997..e7a5bb084ee5 100644 --- a/sys/netpfil/pf/pf_ioctl.c +++ b/sys/netpfil/pf/pf_ioctl.c @@ -2595,16 +2595,12 @@ pfioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td if (V_pf_status.running) error = EEXIST; else { - int cpu; - hook_pf(); if (! TAILQ_EMPTY(V_pf_keth->active.rules)) hook_pf_eth(); V_pf_status.running = 1; V_pf_status.since = time_second; - - CPU_FOREACH(cpu) - V_pf_stateid[cpu] = time_second; + new_unrhdr64(&V_pf_stateid, time_second); DPFPRINTF(PF_DEBUG_MISC, ("pf: started\n")); }