diff options
Diffstat (limited to 'src/resolve/resolved-dns-answer.c')
-rw-r--r-- | src/resolve/resolved-dns-answer.c | 331 |
1 files changed, 279 insertions, 52 deletions
diff --git a/src/resolve/resolved-dns-answer.c b/src/resolve/resolved-dns-answer.c index 4db67f7278..de8c4d9dd3 100644 --- a/src/resolve/resolved-dns-answer.c +++ b/src/resolve/resolved-dns-answer.c @@ -46,6 +46,18 @@ DnsAnswer *dns_answer_ref(DnsAnswer *a) { return a; } +static void dns_answer_flush(DnsAnswer *a) { + DnsResourceRecord *rr; + + if (!a) + return; + + DNS_ANSWER_FOREACH(rr, a) + dns_resource_record_unref(rr); + + a->n_rrs = 0; +} + DnsAnswer *dns_answer_unref(DnsAnswer *a) { if (!a) return NULL; @@ -53,11 +65,7 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) { assert(a->n_ref > 0); if (a->n_ref == 1) { - unsigned i; - - for (i = 0; i < a->n_rrs; i++) - dns_resource_record_unref(a->items[i].rr); - + dns_answer_flush(a); free(a); } else a->n_ref--; @@ -65,6 +73,35 @@ DnsAnswer *dns_answer_unref(DnsAnswer *a) { return NULL; } +static int dns_answer_add_raw(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { + assert(rr); + + if (!a) + return -ENOSPC; + + if (a->n_rrs >= a->n_allocated) + return -ENOSPC; + + a->items[a->n_rrs].rr = dns_resource_record_ref(rr); + a->items[a->n_rrs].ifindex = ifindex; + a->n_rrs++; + + return 1; +} + +static int dns_answer_add_raw_all(DnsAnswer *a, DnsAnswer *source) { + DnsResourceRecord *rr; + int ifindex, r; + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, source) { + r = dns_answer_add_raw(a, rr, ifindex); + if (r < 0) + return r; + } + + return 0; +} + int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { unsigned i; int r; @@ -73,6 +110,8 @@ int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { if (!a) return -ENOSPC; + if (a->n_ref > 1) + return -EBUSY; for (i = 0; i < a->n_rrs; i++) { if (a->items[i].ifindex != ifindex) @@ -95,14 +134,33 @@ int dns_answer_add(DnsAnswer *a, DnsResourceRecord *rr, int ifindex) { } } - if (a->n_rrs >= a->n_allocated) - return -ENOSPC; + return dns_answer_add_raw(a, rr, ifindex); +} - a->items[a->n_rrs].rr = dns_resource_record_ref(rr); - a->items[a->n_rrs].ifindex = ifindex; - a->n_rrs++; +static int dns_answer_add_all(DnsAnswer *a, DnsAnswer *b) { + DnsResourceRecord *rr; + int ifindex, r; - return 1; + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, b) { + r = dns_answer_add(a, rr, ifindex); + if (r < 0) + return r; + } + + return 0; +} + +int dns_answer_add_extend(DnsAnswer **a, DnsResourceRecord *rr, int ifindex) { + int r; + + assert(a); + assert(rr); + + r = dns_answer_reserve_or_clone(a, 1); + if (r < 0) + return r; + + return dns_answer_add(*a, rr, ifindex); } int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl) { @@ -131,8 +189,8 @@ int dns_answer_add_soa(DnsAnswer *a, const char *name, uint32_t ttl) { return dns_answer_add(a, soa, 0); } -int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { - unsigned i; +int dns_answer_match_key(DnsAnswer *a, const DnsResourceKey *key) { + DnsResourceRecord *i; int r; assert(key); @@ -140,8 +198,8 @@ int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { if (!a) return 0; - for (i = 0; i < a->n_rrs; i++) { - r = dns_resource_key_match_rr(key, a->items[i].rr, NULL); + DNS_ANSWER_FOREACH(i, a) { + r = dns_resource_key_match_rr(key, i, NULL); if (r < 0) return r; if (r > 0) @@ -151,21 +209,25 @@ int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key) { return 0; } -int dns_answer_match_soa(DnsResourceKey *key, DnsResourceKey *soa) { - if (soa->class != DNS_CLASS_IN) - return 0; +int dns_answer_contains_rr(DnsAnswer *a, DnsResourceRecord *rr) { + DnsResourceRecord *i; + int r; - if (soa->type != DNS_TYPE_SOA) - return 0; + assert(rr); - if (!dns_name_endswith(DNS_RESOURCE_KEY_NAME(key), DNS_RESOURCE_KEY_NAME(soa))) - return 0; + DNS_ANSWER_FOREACH(i, a) { + r = dns_resource_record_equal(i, rr); + if (r < 0) + return r; + if (r > 0) + return 1; + } - return 1; + return 0; } -int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret) { - unsigned i; +int dns_answer_find_soa(DnsAnswer *a, const DnsResourceKey *key, DnsResourceRecord **ret) { + DnsResourceRecord *rr; assert(key); assert(ret); @@ -177,10 +239,9 @@ int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **r if (key->type == DNS_TYPE_SOA) return 0; - for (i = 0; i < a->n_rrs; i++) { - - if (dns_answer_match_soa(key, a->items[i].rr->key)) { - *ret = a->items[i].rr; + DNS_ANSWER_FOREACH(rr, a) { + if (dns_resource_key_match_soa(key, rr->key)) { + *ret = rr; return 1; } } @@ -188,41 +249,169 @@ int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **r return 0; } -DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b) { - _cleanup_(dns_answer_unrefp) DnsAnswer *ret = NULL; - DnsAnswer *k; +int dns_answer_merge(DnsAnswer *a, DnsAnswer *b, DnsAnswer **ret) { + _cleanup_(dns_answer_unrefp) DnsAnswer *k = NULL; + int r; + + assert(ret); + + if (dns_answer_size(a) <= 0) { + *ret = dns_answer_ref(b); + return 0; + } + + if (dns_answer_size(b) <= 0) { + *ret = dns_answer_ref(a); + return 0; + } + + k = dns_answer_new(a->n_rrs + b->n_rrs); + if (!k) + return -ENOMEM; + + r = dns_answer_add_raw_all(k, a); + if (r < 0) + return r; + + r = dns_answer_add_all(k, b); + if (r < 0) + return r; + + *ret = k; + k = NULL; + + return 0; +} + +int dns_answer_extend(DnsAnswer **a, DnsAnswer *b) { + DnsAnswer *merged; + int r; + + assert(a); + + r = dns_answer_merge(*a, b, &merged); + if (r < 0) + return r; + + dns_answer_unref(*a); + *a = merged; + + return 0; +} + +int dns_answer_remove_by_key(DnsAnswer **a, const DnsResourceKey *key) { + bool found = false, other = false; + DnsResourceRecord *rr; unsigned i; int r; - if (a && (!b || b->n_rrs <= 0)) - return dns_answer_ref(a); - if ((!a || a->n_rrs <= 0) && b) - return dns_answer_ref(b); + assert(a); + assert(key); - ret = dns_answer_new((a ? a->n_rrs : 0) + (b ? b->n_rrs : 0)); - if (!ret) - return NULL; + /* Remove all entries matching the specified key from *a */ - if (a) { - for (i = 0; i < a->n_rrs; i++) { - r = dns_answer_add(ret, a->items[i].rr, a->items[i].ifindex); - if (r < 0) - return NULL; - } + DNS_ANSWER_FOREACH(rr, *a) { + r = dns_resource_key_equal(rr->key, key); + if (r < 0) + return r; + if (r > 0) + found = true; + else + other = true; + + if (found && other) + break; + } + + if (!found) + return 0; + + if (!other) { + *a = dns_answer_unref(*a); /* Return NULL for the empty answer */ + return 1; } - if (b) { - for (i = 0; i < b->n_rrs; i++) { - r = dns_answer_add(ret, b->items[i].rr, b->items[i].ifindex); + if ((*a)->n_ref > 1) { + _cleanup_(dns_answer_unrefp) DnsAnswer *copy = NULL; + int ifindex; + + copy = dns_answer_new((*a)->n_rrs); + if (!copy) + return -ENOMEM; + + DNS_ANSWER_FOREACH_IFINDEX(rr, ifindex, *a) { + r = dns_resource_key_equal(rr->key, key); if (r < 0) - return NULL; + return r; + if (r > 0) + continue; + + r = dns_answer_add_raw(copy, rr, ifindex); + if (r < 0) + return r; } + + dns_answer_unref(*a); + *a = copy; + copy = NULL; + + return 1; } - k = ret; - ret = NULL; + /* Only a single reference, edit in-place */ + + i = 0; + for (;;) { + if (i >= (*a)->n_rrs) + break; - return k; + r = dns_resource_key_equal((*a)->items[i].rr->key, key); + if (r < 0) + return r; + if (r > 0) { + /* Kill this entry */ + + dns_resource_record_unref((*a)->items[i].rr); + memmove((*a)->items + i, (*a)->items + i + 1, sizeof(DnsAnswerItem) * ((*a)->n_rrs - i - 1)); + (*a)->n_rrs --; + continue; + + } else + /* Keep this entry */ + i++; + } + + return 1; +} + +int dns_answer_copy_by_key(DnsAnswer **a, DnsAnswer *source, const DnsResourceKey *key) { + DnsResourceRecord *rr_source; + int ifindex_source, r; + + assert(a); + assert(key); + + /* Copy all RRs matching the specified key from source into *a */ + + DNS_ANSWER_FOREACH_IFINDEX(rr_source, ifindex_source, source) { + + r = dns_resource_key_equal(rr_source->key, key); + if (r < 0) + return r; + if (r == 0) + continue; + + /* Make space for at least one entry */ + r = dns_answer_reserve_or_clone(a, 1); + if (r < 0) + return r; + + r = dns_answer_add(*a, rr_source, ifindex_source); + if (r < 0) + return r; + } + + return 0; } void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) { @@ -261,6 +450,8 @@ void dns_answer_order_by_scope(DnsAnswer *a, bool prefer_link_local) { int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { DnsAnswer *n; + assert(a); + if (n_free <= 0) return 0; @@ -275,6 +466,9 @@ int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { if ((*a)->n_allocated >= ns) return 0; + /* Allocate more than we need */ + ns *= 2; + n = realloc(*a, offsetof(DnsAnswer, items) + sizeof(DnsAnswerItem) * ns); if (!n) return -ENOMEM; @@ -289,3 +483,36 @@ int dns_answer_reserve(DnsAnswer **a, unsigned n_free) { *a = n; return 0; } + +int dns_answer_reserve_or_clone(DnsAnswer **a, unsigned n_free) { + _cleanup_(dns_answer_unrefp) DnsAnswer *n = NULL; + int r; + + assert(a); + + /* Tries to extend the DnsAnswer object. And if that's not + * possibly, since we are not the sole owner, then allocate a + * new, appropriately sized one. Either way, after this call + * the object will only have a single reference, and has room + * for at least the specified number of RRs. */ + + r = dns_answer_reserve(a, n_free); + if (r != -EBUSY) + return r; + + assert(*a); + + n = dns_answer_new(((*a)->n_rrs + n_free) * 2); + if (!n) + return -ENOMEM; + + r = dns_answer_add_raw_all(n, *a); + if (r < 0) + return r; + + dns_answer_unref(*a); + *a = n; + n = NULL; + + return 0; +} |