diff options
Diffstat (limited to 'nest')
| -rw-r--r-- | nest/a-path.c | 63 | ||||
| -rw-r--r-- | nest/attrs.h | 2 |
2 files changed, 65 insertions, 0 deletions
diff --git a/nest/a-path.c b/nest/a-path.c index 712e77a3..b1812981 100644 --- a/nest/a-path.c +++ b/nest/a-path.c @@ -287,6 +287,69 @@ as_path_match_set(struct adata *path, struct f_tree *set) return 0; } +struct adata * +as_path_filter(struct linpool *pool, struct adata *path, struct f_tree *set, u32 key, int pos) +{ + if (!path) + return NULL; + + int len = path->length; + u8 *p = path->data; + u8 *q = path->data + len; + u8 *d, *d2; + int i, bt, sn, dn; + u8 buf[len]; + + d = buf; + while (p<q) + { + /* Read block header (type and length) */ + bt = p[0]; + sn = p[1]; + dn = 0; + p += 2; + d2 = d + 2; + + for (i = 0; i < sn; i++) + { + u32 as = get_as(p); + int match; + + if (set) + match = !!find_tree(set, (struct f_val){T_INT, .val.i = as}); + else + match = (as == key); + + if (match == pos) + { + put_as(d2, as); + d2 += BS; + dn++; + } + + p += BS; + } + + if (dn > 0) + { + /* Nonempty block, set block header and advance */ + d[0] = bt; + d[1] = dn; + d = d2; + } + } + + int nl = d - buf; + if (nl == path->length) + return path; + + struct adata *res = lp_alloc(pool, sizeof(struct adata) + nl); + res->length = nl; + memcpy(res->data, buf, nl); + + return res; +} + struct pm_pos { diff --git a/nest/attrs.h b/nest/attrs.h index 12f2fcf4..44a23e18 100644 --- a/nest/attrs.h +++ b/nest/attrs.h @@ -37,6 +37,8 @@ int as_path_get_first(struct adata *path, u32 *orig_as); int as_path_get_last(struct adata *path, u32 *last_as); int as_path_is_member(struct adata *path, u32 as); int as_path_match_set(struct adata *path, struct f_tree *set); +struct adata *as_path_filter(struct linpool *pool, struct adata *path, struct f_tree *set, u32 key, int pos); + #define PM_ASN 0 #define PM_QUESTION 1 |