diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/rplan.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/lib/rplan.c b/lib/rplan.c new file mode 100644 index 0000000..0bedd8a --- /dev/null +++ b/lib/rplan.c @@ -0,0 +1,291 @@ +/* Copyright (C) CZ.NIC, z.s.p.o. <knot-resolver@labs.nic.cz> + * SPDX-License-Identifier: GPL-3.0-or-later + */ + +#include <libknot/descriptor.h> +#include <libknot/errcode.h> + +#include "lib/rplan.h" +#include "lib/resolve.h" + +#define VERBOSE_MSG(qry, ...) kr_log_q(qry, PLAN, __VA_ARGS__) + +inline static unsigned char chars_or(const unsigned char a, const unsigned char b) +{ + return a | b; +} + +/** Bits set to 1 in variable b will be set to zero in variable a. */ +inline static unsigned char chars_mask(const unsigned char a, const unsigned char b) +{ + return a & ~b; +} + +/** Apply mod(a, b) to every byte a, b from fl1, fl2 and return result in fl1. */ +inline static void kr_qflags_mod(struct kr_qflags *fl1, struct kr_qflags fl2, + unsigned char mod(const unsigned char a, const unsigned char b)) +{ + kr_require(fl1); + union { + struct kr_qflags flags; + /* C99 section 6.5.3.4: sizeof(char) == 1 */ + unsigned char chars[sizeof(struct kr_qflags)]; + } tmp1, tmp2; + /* The compiler should be able to optimize all this into simple ORs. */ + tmp1.flags = *fl1; + tmp2.flags = fl2; + for (size_t i = 0; i < sizeof(struct kr_qflags); ++i) { + tmp1.chars[i] = mod(tmp1.chars[i], tmp2.chars[i]); + } + *fl1 = tmp1.flags; +} + +/** + * Set bits from variable fl2 in variable fl1. + * Bits which are not set in fl2 are not modified in fl1. + * + * @param[in,out] fl1 + * @param[in] fl2 + */ +void kr_qflags_set(struct kr_qflags *fl1, struct kr_qflags fl2) +{ + kr_qflags_mod(fl1, fl2, chars_or); +} + +/** + * Clear bits from variable fl2 in variable fl1. + * Bits which are not set in fl2 are not modified in fl1. + * + * @param[in,out] fl1 + * @param[in] fl2 + */ +void kr_qflags_clear(struct kr_qflags *fl1, struct kr_qflags fl2) +{ + kr_qflags_mod(fl1, fl2, chars_mask); +} + +static struct kr_query *query_create(knot_mm_t *pool, const knot_dname_t *name, uint32_t uid) +{ + struct kr_query *qry = mm_calloc(pool, 1, sizeof(*qry)); + if (qry == NULL) { + return NULL; + } + + if (name != NULL) { + qry->sname = knot_dname_copy(name, pool); + if (qry->sname == NULL) { + mm_free(pool, qry); + return NULL; + } + } + + knot_dname_to_lower(qry->sname); + qry->uid = uid; + return qry; +} + +static void query_free(knot_mm_t *pool, struct kr_query *qry) +{ + kr_zonecut_deinit(&qry->zone_cut); + mm_free(pool, qry->sname); + mm_free(pool, qry); +} + +int kr_rplan_init(struct kr_rplan *rplan, struct kr_request *request, knot_mm_t *pool) +{ + if (rplan == NULL) { + return KNOT_EINVAL; + } + + memset(rplan, 0, sizeof(struct kr_rplan)); + + rplan->pool = pool; + rplan->request = request; + array_init(rplan->pending); + array_init(rplan->resolved); + rplan->next_uid = 0; + return KNOT_EOK; +} + +void kr_rplan_deinit(struct kr_rplan *rplan) +{ + if (rplan == NULL) { + return; + } + + for (size_t i = 0; i < rplan->pending.len; ++i) { + query_free(rplan->pool, rplan->pending.at[i]); + } + for (size_t i = 0; i < rplan->resolved.len; ++i) { + query_free(rplan->pool, rplan->resolved.at[i]); + } + array_clear_mm(rplan->pending, mm_free, rplan->pool); + array_clear_mm(rplan->resolved, mm_free, rplan->pool); +} + +bool kr_rplan_empty(struct kr_rplan *rplan) +{ + if (rplan == NULL) { + return true; + } + + return rplan->pending.len == 0; +} + +static struct kr_query *kr_rplan_push_query(struct kr_rplan *rplan, + struct kr_query *parent, + const knot_dname_t *name) +{ + if (rplan == NULL) { + return NULL; + } + + /* Make sure there's enough space */ + int ret = array_reserve_mm(rplan->pending, rplan->pending.len + 1, kr_memreserve, rplan->pool); + if (ret != 0) { + return NULL; + } + + struct kr_query *qry = query_create(rplan->pool, name, rplan->next_uid); + if (qry == NULL) { + return NULL; + } + rplan->next_uid += 1; + /* Class and type must be set outside this function. */ + qry->flags = rplan->request->options; + qry->parent = parent; + qry->request = rplan->request; + + gettimeofday(&qry->timestamp, NULL); + qry->timestamp_mono = kr_now(); + qry->creation_time_mono = parent ? parent->creation_time_mono : qry->timestamp_mono; + kr_zonecut_init(&qry->zone_cut, (const uint8_t *)"", rplan->pool); + qry->reorder = qry->flags.REORDER_RR ? kr_rand_bytes(sizeof(qry->reorder)) : 0; + + + kr_assert((rplan->pending.len == 0 && rplan->resolved.len == 0) + == (rplan->initial == NULL)); + if (rplan->initial == NULL) { + rplan->initial = qry; + } + + array_push(rplan->pending, qry); + + return qry; +} + +struct kr_query *kr_rplan_push_empty(struct kr_rplan *rplan, struct kr_query *parent) +{ + if (rplan == NULL) { + return NULL; + } + + struct kr_query *qry = kr_rplan_push_query(rplan, parent, NULL); + if (qry == NULL) { + return NULL; + } + + VERBOSE_MSG(qry, "plan '%s' type '%s' uid [%05u.%02u]\n", "", "", + qry->request ? qry->request->uid : 0, qry->uid); + return qry; +} + +struct kr_query *kr_rplan_push(struct kr_rplan *rplan, struct kr_query *parent, + const knot_dname_t *name, uint16_t cls, uint16_t type) +{ + if (rplan == NULL || name == NULL) { + return NULL; + } + + struct kr_query *qry = kr_rplan_push_query(rplan, parent, name); + if (qry == NULL) { + return NULL; + } + + qry->sclass = cls; + qry->stype = type; + + if (kr_log_is_debug_qry(PLAN, qry)) { + KR_DNAME_GET_STR(name_str, name); + KR_RRTYPE_GET_STR(type_str, type); + VERBOSE_MSG(parent, "plan '%s' type '%s' uid [%05u.%02u]\n", + name_str, type_str, + qry->request ? qry->request->uid : 0, qry->uid); + } + return qry; +} + +int kr_rplan_pop(struct kr_rplan *rplan, struct kr_query *qry) +{ + if (rplan == NULL || qry == NULL) { + return KNOT_EINVAL; + } + + /* Make sure there's enough space */ + int ret = array_reserve_mm(rplan->resolved, rplan->resolved.len + 1, kr_memreserve, rplan->pool); + if (ret != 0) { + return ret; + } + + /* Find the query, it will likely be on top */ + for (size_t i = rplan->pending.len; i > 0; i--) { + if (rplan->pending.at[i - 1] == qry) { + /* Delete i-1 element by *sliding* the rest, + * contrary to array_del() */ + for (size_t j = i; j < rplan->pending.len; ++j) + rplan->pending.at[j - 1] = rplan->pending.at[j]; + array_pop(rplan->pending); + + array_push(rplan->resolved, qry); + break; + } + } + return KNOT_EOK; +} + +bool kr_rplan_satisfies(struct kr_query *closure, const knot_dname_t *name, uint16_t cls, uint16_t type) +{ + while (name && closure) { + if (closure->sclass == cls && closure->stype == type + && knot_dname_is_equal(closure->sname, name)) { + return true; + } + closure = closure->parent; + } + return false; +} + +struct kr_query *kr_rplan_resolved(struct kr_rplan *rplan) +{ + if (rplan->resolved.len == 0) { + return NULL; + } + return array_tail(rplan->resolved); +} + +struct kr_query *kr_rplan_last(struct kr_rplan *rplan) +{ + if (!kr_rplan_empty(rplan)) { + return array_tail(rplan->pending); + } + + return kr_rplan_resolved(rplan); +} + +struct kr_query *kr_rplan_find_resolved(struct kr_rplan *rplan, struct kr_query *parent, + const knot_dname_t *name, uint16_t cls, uint16_t type) +{ + struct kr_query *ret = NULL; + for (int i = 0; i < rplan->resolved.len; ++i) { + struct kr_query *q = rplan->resolved.at[i]; + if (q->stype == type && q->sclass == cls && + (parent == NULL || q->parent == parent) && + knot_dname_is_equal(q->sname, name)) { + ret = q; + break; + } + } + return ret; +} + +#undef VERBOSE_MSG |