In general it is a bad idea to use one random secret for two things.

The inet PCB uses one hash with local and foreign addresses, and
one with local port numbers.  Give both hashes separate keys.  Also
document the struct fields.
OK visa@

diff --git a/sys/netinet/in_pcb.c b/sys/netinet/in_pcb.c
index 346c935..02a1e88 100644 (file)
--- a/sys/netinet/in_pcb.c
+++ b/sys/netinet/in_pcb.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in_pcb.c,v 1.244 2018/09/13 19:53:58 bluhm Exp $      */
+/*     $OpenBSD: in_pcb.c,v 1.245 2018/09/14 12:55:17 bluhm Exp $      */
 /*     $NetBSD: in_pcb.c,v 1.25 1996/02/13 23:41:53 christos Exp $     */
 
 /*
@@ -148,7 +148,7 @@ in_pcblhash(struct inpcbtable *table, int rdom, u_short lport)
        SIPHASH_CTX ctx;
        u_int32_t nrdom = htonl(rdom);
 
-       SipHash24_Init(&ctx, &table->inpt_key);
+       SipHash24_Init(&ctx, &table->inpt_lkey);
        SipHash24_Update(&ctx, &nrdom, sizeof(nrdom));
        SipHash24_Update(&ctx, &lport, sizeof(lport));
 
@@ -171,6 +171,7 @@ in_pcbinit(struct inpcbtable *table, int hashsize)
        table->inpt_count = 0;
        table->inpt_size = hashsize;
        arc4random_buf(&table->inpt_key, sizeof(table->inpt_key));
+       arc4random_buf(&table->inpt_lkey, sizeof(table->inpt_lkey));
 }
 
 /*
@@ -999,6 +1000,7 @@ in_pcbresize(struct inpcbtable *table, int hashsize)
        table->inpt_lmask = nlmask;
        table->inpt_size = hashsize;
        arc4random_buf(&table->inpt_key, sizeof(table->inpt_key));
+       arc4random_buf(&table->inpt_lkey, sizeof(table->inpt_lkey));
 
        TAILQ_FOREACH(inp, &table->inpt_queue, inp_queue) {
                in_pcbrehash(inp);

diff --git a/sys/netinet/in_pcb.h b/sys/netinet/in_pcb.h
index 984adb4..8b90762 100644 (file)
--- a/sys/netinet/in_pcb.h
+++ b/sys/netinet/in_pcb.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: in_pcb.h,v 1.112 2018/09/14 07:25:02 jsg Exp $        */
+/*     $OpenBSD: in_pcb.h,v 1.113 2018/09/14 12:55:17 bluhm Exp $      */
 /*     $NetBSD: in_pcb.h,v 1.14 1996/02/13 23:42:00 christos Exp $     */
 
 /*
@@ -91,10 +91,10 @@ union inpaddru {
  * control block.
  */
 struct inpcb {
-       LIST_ENTRY(inpcb) inp_hash;
-       LIST_ENTRY(inpcb) inp_lhash;            /* extra hash for lport */
-       TAILQ_ENTRY(inpcb) inp_queue;
-       struct    inpcbtable *inp_table;
+       LIST_ENTRY(inpcb) inp_hash;             /* local and foreign hash */
+       LIST_ENTRY(inpcb) inp_lhash;            /* local port hash */
+       TAILQ_ENTRY(inpcb) inp_queue;           /* inet PCB queue */
+       struct    inpcbtable *inp_table;        /* inet queue/hash table */
        union     inpaddru inp_faddru;          /* Foreign address. */
        union     inpaddru inp_laddru;          /* Local address. */
 #define        inp_faddr       inp_faddru.iau_a4u.inaddr
@@ -150,11 +150,12 @@ struct inpcb {
 LIST_HEAD(inpcbhead, inpcb);
 
 struct inpcbtable {
-       TAILQ_HEAD(inpthead, inpcb) inpt_queue;
-       struct inpcbhead *inpt_hashtbl, *inpt_lhashtbl;
-       SIPHASH_KEY inpt_key;
-       u_long    inpt_mask, inpt_lmask;
-       int       inpt_count, inpt_size;
+       TAILQ_HEAD(inpthead, inpcb) inpt_queue; /* inet PCB queue */
+       struct  inpcbhead *inpt_hashtbl;        /* local and foreign hash */
+       struct  inpcbhead *inpt_lhashtbl;       /* local port hash */
+       SIPHASH_KEY inpt_key, inpt_lkey;        /* secrets for hashes */
+       u_long  inpt_mask, inpt_lmask;          /* hash masks */
+       int     inpt_count, inpt_size;          /* queue count, hash size */
 };
 
 /* flags in inp_flags: */