Commit c18865f39276435abb9286f9a816cb5b66c99a00
Committed by
David S. Miller
David S. Miller
1 parent
ec9dbb1c3e
Exists in
master
and in
7 other branches
[IPV4] fib: fix route replacement, fib_info is shared
fib_info can be shared by many route prefixes but we don't want duplicate alternative routes for a prefix+tos+priority. Last change was not correct to check fib_treeref because it accounts usage from other prefixes. Additionally, avoid replacement without error if new route is same, as Joonwoo Park suggests. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: David S. Miller <davem@davemloft.net>
Showing 1 changed file with 31 additions and 16 deletions Side-by-side Diff
net/ipv4/fib_hash.c
| ... | ... | @@ -424,19 +424,43 @@ |
| 424 | 424 | |
| 425 | 425 | if (fa && fa->fa_tos == tos && |
| 426 | 426 | fa->fa_info->fib_priority == fi->fib_priority) { |
| 427 | - struct fib_alias *fa_orig; | |
| 427 | + struct fib_alias *fa_first, *fa_match; | |
| 428 | 428 | |
| 429 | 429 | err = -EEXIST; |
| 430 | 430 | if (cfg->fc_nlflags & NLM_F_EXCL) |
| 431 | 431 | goto out; |
| 432 | 432 | |
| 433 | + /* We have 2 goals: | |
| 434 | + * 1. Find exact match for type, scope, fib_info to avoid | |
| 435 | + * duplicate routes | |
| 436 | + * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it | |
| 437 | + */ | |
| 438 | + fa_match = NULL; | |
| 439 | + fa_first = fa; | |
| 440 | + fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); | |
| 441 | + list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { | |
| 442 | + if (fa->fa_tos != tos) | |
| 443 | + break; | |
| 444 | + if (fa->fa_info->fib_priority != fi->fib_priority) | |
| 445 | + break; | |
| 446 | + if (fa->fa_type == cfg->fc_type && | |
| 447 | + fa->fa_scope == cfg->fc_scope && | |
| 448 | + fa->fa_info == fi) { | |
| 449 | + fa_match = fa; | |
| 450 | + break; | |
| 451 | + } | |
| 452 | + } | |
| 453 | + | |
| 433 | 454 | if (cfg->fc_nlflags & NLM_F_REPLACE) { |
| 434 | 455 | struct fib_info *fi_drop; |
| 435 | 456 | u8 state; |
| 436 | 457 | |
| 437 | - if (fi->fib_treeref > 1) | |
| 458 | + fa = fa_first; | |
| 459 | + if (fa_match) { | |
| 460 | + if (fa == fa_match) | |
| 461 | + err = 0; | |
| 438 | 462 | goto out; |
| 439 | - | |
| 463 | + } | |
| 440 | 464 | write_lock_bh(&fib_hash_lock); |
| 441 | 465 | fi_drop = fa->fa_info; |
| 442 | 466 | fa->fa_info = fi; |
| 443 | 467 | |
| ... | ... | @@ -459,20 +483,11 @@ |
| 459 | 483 | * uses the same scope, type, and nexthop |
| 460 | 484 | * information. |
| 461 | 485 | */ |
| 462 | - fa_orig = fa; | |
| 463 | - fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); | |
| 464 | - list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { | |
| 465 | - if (fa->fa_tos != tos) | |
| 466 | - break; | |
| 467 | - if (fa->fa_info->fib_priority != fi->fib_priority) | |
| 468 | - break; | |
| 469 | - if (fa->fa_type == cfg->fc_type && | |
| 470 | - fa->fa_scope == cfg->fc_scope && | |
| 471 | - fa->fa_info == fi) | |
| 472 | - goto out; | |
| 473 | - } | |
| 486 | + if (fa_match) | |
| 487 | + goto out; | |
| 488 | + | |
| 474 | 489 | if (!(cfg->fc_nlflags & NLM_F_APPEND)) |
| 475 | - fa = fa_orig; | |
| 490 | + fa = fa_first; | |
| 476 | 491 | } |
| 477 | 492 | |
| 478 | 493 | err = -ENOENT; |