git: 220d89212943 - main - inpcb: immediately return matching pcb on lookup

The branch main has been updated by glebius:

URL: https://cgit.FreeBSD.org/src/commit/?id=220d892129439e4596b8ef054f56b6e0ede03538

commit 220d892129439e4596b8ef054f56b6e0ede03538
Author:     Gleb Smirnoff <glebius@FreeBSD.org>
AuthorDate: 2023-02-07 17:21:52 +0000
Commit:     Gleb Smirnoff <glebius@FreeBSD.org>
CommitDate: 2023-02-07 17:21:52 +0000

    inpcb: immediately return matching pcb on lookup
    
    This saves a lot of CPU cycles if you got large connection table.
    
    The code removed originates from 413628a7e3d, a very large changeset.
    Discussed that with Bjoern, Jamie we can't recover why would we ever
    have identical 4-tuples in the hash, even in the presence of jails.
    Bjoern did a test that confirms that it is impossible to allocate an
    identical connection from a jail to a host. Code review also confirms
    that system shouldn't allow for such connections to exist.
    
    With a lack of proper test suite we decided to take a risk and go
    forward with removing that code.
    
    Reviewed by:            gallatin, bz, markj
    Differential Revision:  https://reviews.freebsd.org/D38015
---
 sys/netinet/in_pcb.c   | 18 +++---------------
 sys/netinet6/in6_pcb.c | 18 +++---------------
 2 files changed, 6 insertions(+), 30 deletions(-)

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index 2a775ff5fc31..728178f1011c 100644
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -2225,7 +2225,7 @@ in_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in_addr faddr,
     struct ifnet *ifp, uint8_t numa_domain)
 {
 	struct inpcbhead *head;
-	struct inpcb *inp, *tmpinp;
+	struct inpcb *inp;
 	u_short fport = fport_arg, lport = lport_arg;
 
 	KASSERT((lookupflags & ~(INPLOOKUP_WILDCARD)) == 0,
@@ -2239,7 +2239,6 @@ in_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in_addr faddr,
 	/*
 	 * First look for an exact match.
 	 */
-	tmpinp = NULL;
 	head = &pcbinfo->ipi_hashbase[INP_PCBHASH(&faddr, lport, fport,
 	    pcbinfo->ipi_hashmask)];
 	CK_LIST_FOREACH(inp, head, inp_hash) {
@@ -2251,20 +2250,9 @@ in_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in_addr faddr,
 		if (inp->inp_faddr.s_addr == faddr.s_addr &&
 		    inp->inp_laddr.s_addr == laddr.s_addr &&
 		    inp->inp_fport == fport &&
-		    inp->inp_lport == lport) {
-			/*
-			 * XXX We should be able to directly return
-			 * the inp here, without any checks.
-			 * Well unless both bound with SO_REUSEPORT?
-			 */
-			if (prison_flag(inp->inp_cred, PR_IP4))
-				return (inp);
-			if (tmpinp == NULL)
-				tmpinp = inp;
-		}
+		    inp->inp_lport == lport)
+			return (inp);
 	}
-	if (tmpinp != NULL)
-		return (tmpinp);
 
 	/*
 	 * Then look for a wildcard match, if requested.
diff --git a/sys/netinet6/in6_pcb.c b/sys/netinet6/in6_pcb.c
index 1b57fce7ec47..80540f2695e7 100644
--- a/sys/netinet6/in6_pcb.c
+++ b/sys/netinet6/in6_pcb.c
@@ -966,7 +966,7 @@ in6_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
     int lookupflags, struct ifnet *ifp, uint8_t numa_domain)
 {
 	struct inpcbhead *head;
-	struct inpcb *inp, *tmpinp;
+	struct inpcb *inp;
 	u_short fport = fport_arg, lport = lport_arg;
 
 	KASSERT((lookupflags & ~(INPLOOKUP_WILDCARD)) == 0,
@@ -981,7 +981,6 @@ in6_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
 	/*
 	 * First look for an exact match.
 	 */
-	tmpinp = NULL;
 	head = &pcbinfo->ipi_hashbase[INP6_PCBHASH(faddr, lport, fport,
 	    pcbinfo->ipi_hashmask)];
 	CK_LIST_FOREACH(inp, head, inp_hash) {
@@ -991,20 +990,9 @@ in6_pcblookup_hash_locked(struct inpcbinfo *pcbinfo, struct in6_addr *faddr,
 		if (IN6_ARE_ADDR_EQUAL(&inp->in6p_faddr, faddr) &&
 		    IN6_ARE_ADDR_EQUAL(&inp->in6p_laddr, laddr) &&
 		    inp->inp_fport == fport &&
-		    inp->inp_lport == lport) {
-			/*
-			 * XXX We should be able to directly return
-			 * the inp here, without any checks.
-			 * Well unless both bound with SO_REUSEPORT?
-			 */
-			if (prison_flag(inp->inp_cred, PR_IP6))
-				return (inp);
-			if (tmpinp == NULL)
-				tmpinp = inp;
-		}
+		    inp->inp_lport == lport)
+			return (inp);
 	}
-	if (tmpinp != NULL)
-		return (tmpinp);
 
 	/*
 	 * Then look for a wildcard match, if requested.