Date: Tue, 29 Oct 2013 13:00:02 GMT From: dfilter@FreeBSD.ORG (dfilter service) To: freebsd-net@FreeBSD.org Subject: Re: kern/134531: commit references a PR Message-ID: <201310291300.r9TD022d040342@freefall.freebsd.org>
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The following reply was made to PR kern/134531; it has been noted by GNATS. From: dfilter@FreeBSD.ORG (dfilter service) To: bug-followup@FreeBSD.org Cc: Subject: Re: kern/134531: commit references a PR Date: Tue, 29 Oct 2013 12:53:33 +0000 (UTC) Author: melifaro Date: Tue Oct 29 12:53:23 2013 New Revision: 257330 URL: http://svnweb.freebsd.org/changeset/base/257330 Log: MFC r256624: Fix long-standing issue with incorrect radix mask calculation. Usual symptoms are messages like rn_delete: inconsistent annotation rn_addmask: mask impossibly already in tree routing daemon constantly deleting IPv6 default route or inability to flush/delete particular prefix in ipfw table. Changes: * Assume 32 bytes as maximum radix key length * Remove rn_init() * Statically allocate rn_ones/rn_zeroes * Make separate mask tree for each "normal" tree instead of system global one * Remove "optimization" on masks reusage and key zeroying * Change rn_addmask() arguments to accept tree pointer (no users in base) MFC changes: * keep rn_init() * create global mask tree, protected with mutex, for old rn_addmask users (currently 0 in base) * Add new rn_addmask_r() function (rn_addmask in head) with additional argument to accept tree pointer PR: kern/182851, kern/169206, kern/135476, kern/134531 Found by: Slawa Olhovchenkov <slw@zxy.spb.ru> Reviewed by: glebius (previous versions) Sponsored by: Yandex LLC Approved by: re (glebius) Modified: stable/10/sys/net/radix.c stable/10/sys/net/radix.h Modified: stable/10/sys/net/radix.c ============================================================================== --- stable/10/sys/net/radix.c Tue Oct 29 12:34:11 2013 (r257329) +++ stable/10/sys/net/radix.c Tue Oct 29 12:53:23 2013 (r257330) @@ -66,27 +66,27 @@ static struct radix_node *rn_search(void *, struct radix_node *), *rn_search_m(void *, struct radix_node *, void *); -static int max_keylen; -static struct radix_mask *rn_mkfreelist; -static struct radix_node_head *mask_rnhead; +static void rn_detachhead_internal(void **head); +static int rn_inithead_internal(void **head, int off); + +#define RADIX_MAX_KEY_LEN 32 + +static char rn_zeros[RADIX_MAX_KEY_LEN]; +static char rn_ones[RADIX_MAX_KEY_LEN] = { + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, +}; + /* - * Work area -- the following point to 3 buffers of size max_keylen, - * allocated in this order in a block of memory malloc'ed by rn_init. - * rn_zeros, rn_ones are set in rn_init and used in readonly afterwards. - * addmask_key is used in rn_addmask in rw mode and not thread-safe. + * XXX: Compat stuff for old rn_addmask() users */ -static char *rn_zeros, *rn_ones, *addmask_key; - -#define MKGet(m) { \ - if (rn_mkfreelist) { \ - m = rn_mkfreelist; \ - rn_mkfreelist = (m)->rm_mklist; \ - } else \ - R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); } - -#define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);} +static struct radix_node_head *mask_rnhead_compat; +#ifdef _KERNEL +static struct mtx mask_mtx; +#endif -#define rn_masktop (mask_rnhead->rnh_treetop) static int rn_lexobetter(void *m_arg, void *n_arg); static struct radix_mask * @@ -230,7 +230,8 @@ rn_lookup(v_arg, m_arg, head) caddr_t netmask = 0; if (m_arg) { - x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset); + x = rn_addmask_r(m_arg, head->rnh_masks, 1, + head->rnh_treetop->rn_offset); if (x == 0) return (0); netmask = x->rn_key; @@ -489,53 +490,47 @@ on1: } struct radix_node * -rn_addmask(n_arg, search, skip) - int search, skip; - void *n_arg; +rn_addmask_r(void *arg, struct radix_node_head *maskhead, int search, int skip) { - caddr_t netmask = (caddr_t)n_arg; + caddr_t netmask = (caddr_t)arg; register struct radix_node *x; register caddr_t cp, cplim; register int b = 0, mlen, j; - int maskduplicated, m0, isnormal; + int maskduplicated, isnormal; struct radix_node *saved_x; - static int last_zeroed = 0; + char addmask_key[RADIX_MAX_KEY_LEN]; - if ((mlen = LEN(netmask)) > max_keylen) - mlen = max_keylen; + if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN) + mlen = RADIX_MAX_KEY_LEN; if (skip == 0) skip = 1; if (mlen <= skip) - return (mask_rnhead->rnh_nodes); + return (maskhead->rnh_nodes); + + bzero(addmask_key, RADIX_MAX_KEY_LEN); if (skip > 1) bcopy(rn_ones + 1, addmask_key + 1, skip - 1); - if ((m0 = mlen) > skip) - bcopy(netmask + skip, addmask_key + skip, mlen - skip); + bcopy(netmask + skip, addmask_key + skip, mlen - skip); /* * Trim trailing zeroes. */ for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;) cp--; mlen = cp - addmask_key; - if (mlen <= skip) { - if (m0 >= last_zeroed) - last_zeroed = mlen; - return (mask_rnhead->rnh_nodes); - } - if (m0 < last_zeroed) - bzero(addmask_key + m0, last_zeroed - m0); - *addmask_key = last_zeroed = mlen; - x = rn_search(addmask_key, rn_masktop); + if (mlen <= skip) + return (maskhead->rnh_nodes); + *addmask_key = mlen; + x = rn_search(addmask_key, maskhead->rnh_treetop); if (bcmp(addmask_key, x->rn_key, mlen) != 0) x = 0; if (x || search) return (x); - R_Zalloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); + R_Zalloc(x, struct radix_node *, RADIX_MAX_KEY_LEN + 2 * sizeof (*x)); if ((saved_x = x) == 0) return (0); netmask = cp = (caddr_t)(x + 2); bcopy(addmask_key, cp, mlen); - x = rn_insert(cp, mask_rnhead, &maskduplicated, x); + x = rn_insert(cp, maskhead, &maskduplicated, x); if (maskduplicated) { log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); Free(saved_x); @@ -568,6 +563,23 @@ rn_addmask(n_arg, search, skip) return (x); } +struct radix_node * +rn_addmask(void *n_arg, int search, int skip) +{ + struct radix_node *tt; + +#ifdef _KERNEL + mtx_lock(&mask_mtx); +#endif + tt = rn_addmask_r(&mask_rnhead_compat, n_arg, search, skip); + +#ifdef _KERNEL + mtx_unlock(&mask_mtx); +#endif + + return (tt); +} + static int /* XXX: arbitrary ordering for non-contiguous masks */ rn_lexobetter(m_arg, n_arg) void *m_arg, *n_arg; @@ -590,12 +602,12 @@ rn_new_radix_mask(tt, next) { register struct radix_mask *m; - MKGet(m); + R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); if (m == 0) { - log(LOG_ERR, "Mask for route not entered\n"); + log(LOG_ERR, "Failed to allocate route mask\n"); return (0); } - bzero(m, sizeof *m); + bzero(m, sizeof(*m)); m->rm_bit = tt->rn_bit; m->rm_flags = tt->rn_flags; if (tt->rn_flags & RNF_NORMAL) @@ -629,7 +641,8 @@ rn_addroute(v_arg, n_arg, head, treenode * nodes and possibly save time in calculating indices. */ if (netmask) { - if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0) + x = rn_addmask_r(netmask, head->rnh_masks, 0, top->rn_offset); + if (x == NULL) return (0); b_leaf = x->rn_bit; b = -1 - x->rn_bit; @@ -808,7 +821,8 @@ rn_delete(v_arg, netmask_arg, head) * Delete our route from mask lists. */ if (netmask) { - if ((x = rn_addmask(netmask, 1, head_off)) == 0) + x = rn_addmask_r(netmask, head->rnh_masks, 1, head_off); + if (x == NULL) return (0); netmask = x->rn_key; while (tt->rn_mask != netmask) @@ -841,7 +855,7 @@ rn_delete(v_arg, netmask_arg, head) for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) if (m == saved_m) { *mp = m->rm_mklist; - MKFree(m); + Free(m); break; } if (m == 0) { @@ -932,7 +946,7 @@ on1: struct radix_mask *mm = m->rm_mklist; x->rn_mklist = 0; if (--(m->rm_refs) < 0) - MKFree(m); + Free(m); m = mm; } if (m) @@ -1128,10 +1142,8 @@ rn_walktree(h, f, w) * bits starting at 'off'. * Return 1 on success, 0 on error. */ -int -rn_inithead(head, off) - void **head; - int off; +static int +rn_inithead_internal(void **head, int off) { register struct radix_node_head *rnh; register struct radix_node *t, *tt, *ttt; @@ -1163,8 +1175,8 @@ rn_inithead(head, off) return (1); } -int -rn_detachhead(void **head) +static void +rn_detachhead_internal(void **head) { struct radix_node_head *rnh; @@ -1176,28 +1188,60 @@ rn_detachhead(void **head) Free(rnh); *head = NULL; +} + +int +rn_inithead(void **head, int off) +{ + struct radix_node_head *rnh; + + if (*head != NULL) + return (1); + + if (rn_inithead_internal(head, off) == 0) + return (0); + + rnh = (struct radix_node_head *)(*head); + + if (rn_inithead_internal((void **)&rnh->rnh_masks, 0) == 0) { + rn_detachhead_internal(head); + return (0); + } + + return (1); +} + +int +rn_detachhead(void **head) +{ + struct radix_node_head *rnh; + + KASSERT((head != NULL && *head != NULL), + ("%s: head already freed", __func__)); + + rnh = *head; + + rn_detachhead_internal((void **)&rnh->rnh_masks); + rn_detachhead_internal(head); return (1); } void rn_init(int maxk) { - char *cp, *cplim; - - max_keylen = maxk; - if (max_keylen == 0) { + if ((maxk <= 0) || (maxk > RADIX_MAX_KEY_LEN)) { log(LOG_ERR, - "rn_init: radix functions require max_keylen be set\n"); + "rn_init: max_keylen must be within 1..%d\n", + RADIX_MAX_KEY_LEN); return; } - R_Malloc(rn_zeros, char *, 3 * max_keylen); - if (rn_zeros == NULL) - panic("rn_init"); - bzero(rn_zeros, 3 * max_keylen); - rn_ones = cp = rn_zeros + max_keylen; - addmask_key = cplim = rn_ones + max_keylen; - while (cp < cplim) - *cp++ = -1; - if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0) + + /* + * XXX: Compat for old rn_addmask() users + */ + if (rn_inithead((void **)(void *)&mask_rnhead_compat, 0) == 0) panic("rn_init 2"); +#ifdef _KERNEL + mtx_init(&mask_mtx, "radix_mask", NULL, MTX_DEF); +#endif } Modified: stable/10/sys/net/radix.h ============================================================================== --- stable/10/sys/net/radix.h Tue Oct 29 12:34:11 2013 (r257329) +++ stable/10/sys/net/radix.h Tue Oct 29 12:53:23 2013 (r257330) @@ -136,6 +136,7 @@ struct radix_node_head { #ifdef _KERNEL struct rwlock rnh_lock; /* locks entire radix tree */ #endif + struct radix_node_head *rnh_masks; /* Storage for our masks */ }; #ifndef _KERNEL @@ -167,6 +168,7 @@ int rn_detachhead(void **); int rn_refines(void *, void *); struct radix_node *rn_addmask(void *, int, int), + *rn_addmask_r(void *, struct radix_node_head *, int, int), *rn_addroute (void *, void *, struct radix_node_head *, struct radix_node [2]), *rn_delete(void *, void *, struct radix_node_head *), _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscribe@freebsd.org"
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