From 636e813dc98ea40c58c6c85bc5e7e3c9f0904ea2 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Tue, 24 Nov 2015 16:48:13 +0100 Subject: [PATCH] resolved: unify code for parsing dns server information Let's use the same parser when parsing dns server information from /etc/resolv.conf and our native configuration file. Also, move all code that manages lists of dns servers to a single place. resolved-dns-server.c --- src/resolve/resolved-conf.c | 66 ++++++++++++++++++++-------------- src/resolve/resolved-conf.h | 5 ++- src/resolve/resolved-dns-server.c | 42 ++++++++++++++++++++++ src/resolve/resolved-dns-server.h | 4 +++ src/resolve/resolved-gperf.gperf | 6 ++-- src/resolve/resolved-manager.c | 75 ++++++++++----------------------------- src/resolve/resolved-manager.h | 2 -- 7 files changed, 110 insertions(+), 90 deletions(-) diff --git a/src/resolve/resolved-conf.c b/src/resolve/resolved-conf.c index 9207719..8b49d46 100644 --- a/src/resolve/resolved-conf.c +++ b/src/resolve/resolved-conf.c @@ -27,53 +27,65 @@ #include "resolved-conf.h" #include "string-util.h" -int manager_parse_dns_server(Manager *m, DnsServerType type, const char *string) { - DnsServer *first; - int r; +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word) { + union in_addr_union address; + DnsServer *first, *s; + int family, r; assert(m); - assert(string); + assert(word); + + r = in_addr_from_string_auto(word, &family, &address); + if (r < 0) + return r; first = type == DNS_SERVER_FALLBACK ? m->fallback_dns_servers : m->dns_servers; + /* Filter out duplicates */ + LIST_FOREACH(servers, s, first) + if (s->family == family && in_addr_equal(family, &s->address, &address)) + break; + + if (s) { + /* + * Drop the marker. This is used to find the servers + * that ceased to exist, see + * manager_mark_dns_servers() and + * manager_flush_marked_dns_servers(). + */ + s->marked = false; + return 0; + } + + return dns_server_new(m, NULL, type, NULL, family, &address); +} + +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string) { + int r; + + assert(m); + assert(string); + for(;;) { _cleanup_free_ char *word = NULL; - union in_addr_union addr; - bool found = false; - DnsServer *s; - int family; r = extract_first_word(&string, &word, NULL, 0); if (r < 0) - return log_error_errno(r, "Failed to parse resolved dns server syntax \"%s\": %m", string); + return r; if (r == 0) break; - r = in_addr_from_string_auto(word, &family, &addr); + r = manager_add_dns_server_by_string(m, type, word); if (r < 0) { - log_warning("Ignoring invalid DNS address '%s'", word); + log_warning_errno(r, "Failed to add DNS server address '%s', ignoring.", word); continue; } - - /* Filter out duplicates */ - LIST_FOREACH(servers, s, first) - if (s->family == family && in_addr_equal(family, &s->address, &addr)) { - found = true; - break; - } - - if (found) - continue; - - r = dns_server_new(m, NULL, type, NULL, family, &addr); - if (r < 0) - return r; } return 0; } -int config_parse_dnsv( +int config_parse_dns_servers( const char *unit, const char *filename, unsigned line, @@ -98,7 +110,7 @@ int config_parse_dnsv( manager_flush_dns_servers(m, ltype); else { /* Otherwise, add to the list */ - r = manager_parse_dns_server(m, ltype, rvalue); + r = manager_parse_dns_server_string_and_warn(m, ltype, rvalue); if (r < 0) { log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse DNS server string '%s'. Ignoring.", rvalue); return 0; diff --git a/src/resolve/resolved-conf.h b/src/resolve/resolved-conf.h index b3dbea7..170f3e9 100644 --- a/src/resolve/resolved-conf.h +++ b/src/resolve/resolved-conf.h @@ -26,7 +26,10 @@ int manager_parse_dns_server(Manager *m, DnsServerType type, const char *string); int manager_parse_config_file(Manager *m); +int manager_parse_dns_server_string_and_warn(Manager *m, DnsServerType type, const char *string); +int manager_add_dns_server_by_string(Manager *m, DnsServerType type, const char *word); + const struct ConfigPerfItem* resolved_gperf_lookup(const char *key, unsigned length); -int config_parse_dnsv(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_dns_servers(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_support(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); diff --git a/src/resolve/resolved-dns-server.c b/src/resolve/resolved-dns-server.c index e803f63..3d6a6c9 100644 --- a/src/resolve/resolved-dns-server.c +++ b/src/resolve/resolved-dns-server.c @@ -161,3 +161,45 @@ const struct hash_ops dns_server_hash_ops = { .hash = dns_server_hash_func, .compare = dns_server_compare_func }; + +void manager_flush_dns_servers(Manager *m, DnsServerType type) { + DnsServer **first, *s; + + assert(m); + + first = type == DNS_SERVER_FALLBACK ? &m->fallback_dns_servers : &m->dns_servers; + + while (*first) { + s = *first; + + LIST_REMOVE(servers, *first, s); + dns_server_unref(s); + } +} + +void manager_flush_marked_dns_servers(Manager *m, DnsServerType type) { + DnsServer **first, *s, *next; + + assert(m); + + first = type == DNS_SERVER_FALLBACK ? &m->fallback_dns_servers : &m->dns_servers; + + LIST_FOREACH_SAFE(servers, s, next, *first) { + if (!s->marked) + continue; + + LIST_REMOVE(servers, *first, s); + dns_server_unref(s); + } +} + +void manager_mark_dns_servers(Manager *m, DnsServerType type) { + DnsServer *first, *s; + + assert(m); + + first = type == DNS_SERVER_FALLBACK ? m->fallback_dns_servers : m->dns_servers; + + LIST_FOREACH(servers, s, first) + s->marked = true; +} diff --git a/src/resolve/resolved-dns-server.h b/src/resolve/resolved-dns-server.h index 10111fd..51cae62 100644 --- a/src/resolve/resolved-dns-server.h +++ b/src/resolve/resolved-dns-server.h @@ -68,6 +68,10 @@ DnsServer* dns_server_unref(DnsServer *s); void dns_server_packet_received(DnsServer *s, usec_t rtt); void dns_server_packet_lost(DnsServer *s, usec_t usec); +void manager_flush_dns_servers(Manager *m, DnsServerType t); +void manager_flush_marked_dns_servers(Manager *m, DnsServerType type); +void manager_mark_dns_servers(Manager *m, DnsServerType type); + DEFINE_TRIVIAL_CLEANUP_FUNC(DnsServer*, dns_server_unref); extern const struct hash_ops dns_server_hash_ops; diff --git a/src/resolve/resolved-gperf.gperf b/src/resolve/resolved-gperf.gperf index 8e78fbf..dc4ef74 100644 --- a/src/resolve/resolved-gperf.gperf +++ b/src/resolve/resolved-gperf.gperf @@ -14,6 +14,6 @@ struct ConfigPerfItem; %struct-type %includes %% -Resolve.DNS, config_parse_dnsv, DNS_SERVER_SYSTEM, 0 -Resolve.FallbackDNS, config_parse_dnsv, DNS_SERVER_FALLBACK, 0 -Resolve.LLMNR, config_parse_support, 0, offsetof(Manager, llmnr_support) +Resolve.DNS, config_parse_dns_servers, DNS_SERVER_SYSTEM, 0 +Resolve.FallbackDNS, config_parse_dns_servers, DNS_SERVER_FALLBACK, 0 +Resolve.LLMNR, config_parse_support, 0, offsetof(Manager, llmnr_support) diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index 7c6500e..c35379a 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -477,7 +477,7 @@ int manager_new(Manager **ret) { m->llmnr_support = SUPPORT_YES; m->read_resolv_conf = true; - r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS); + r = manager_parse_dns_server_string_and_warn(m, DNS_SERVER_FALLBACK, DNS_SERVERS); if (r < 0) return r; @@ -583,7 +583,7 @@ int manager_read_resolv_conf(Manager *m) { _cleanup_fclose_ FILE *f = NULL; struct stat st, own; char line[LINE_MAX]; - DnsServer *s, *nx; + DnsServer *s; usec_t t; int r; @@ -633,14 +633,12 @@ int manager_read_resolv_conf(Manager *m) { goto clear; } - LIST_FOREACH(servers, s, m->dns_servers) - s->marked = true; + manager_mark_dns_servers(m, DNS_SERVER_SYSTEM); FOREACH_LINE(line, f, r = -errno; goto clear) { - union in_addr_union address; - int family; - char *l; + _cleanup_strv_free_ char **d = NULL; const char *a; + char *l; truncate_nl(line); @@ -649,33 +647,16 @@ int manager_read_resolv_conf(Manager *m) { continue; a = first_word(l, "nameserver"); - if (!a) - continue; + if (a) { + r = manager_add_dns_server_by_string(m, DNS_SERVER_SYSTEM, a); + if (r < 0) + log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a); - r = in_addr_from_string_auto(a, &family, &address); - if (r < 0) { - log_warning("Failed to parse name server %s.", a); continue; } - - LIST_FOREACH(servers, s, m->dns_servers) - if (s->family == family && in_addr_equal(family, &s->address, &address) > 0) - break; - - if (s) - s->marked = false; - else { - r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address); - if (r < 0) - goto clear; - } } - LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers) - if (s->marked) { - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } + manager_flush_marked_dns_servers(m, DNS_SERVER_SYSTEM); /* Whenever /etc/resolv.conf changes, start using the first * DNS server of it. This is useful to deal with broken @@ -716,13 +697,14 @@ static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { if (*count == MAXNS) fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); + (*count) ++; fprintf(f, "nameserver %s\n", t); - (*count) ++; } static void write_resolv_conf_search( - const char *domain, FILE *f, + const char *domain, + FILE *f, unsigned *count, unsigned *length) { @@ -740,10 +722,11 @@ static void write_resolv_conf_search( return; } - fprintf(f, " %s", domain); - (*length) += strlen(domain); (*count) ++; + + fputc(' ', f); + fputs(domain, f); } static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { @@ -758,8 +741,8 @@ static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *doma if (ordered_set_isempty(dns)) fputs("# No DNS servers known.\n", f); else { - DnsServer *s; unsigned count = 0; + DnsServer *s; ORDERED_SET_FOREACH(s, dns, i) write_resolv_conf_server(s, f, &count); @@ -802,7 +785,7 @@ int manager_write_resolv_conf(Manager *m) { if (!domains) return -ENOMEM; - /* First add the system-wide servers */ + /* First add the system-wide servers and domains */ LIST_FOREACH(servers, s, m->dns_servers) { r = ordered_set_put(dns, s); if (r == -EEXIST) @@ -1420,28 +1403,6 @@ void manager_verify_all(Manager *m) { dns_zone_verify_all(&s->zone); } -void manager_flush_dns_servers(Manager *m, DnsServerType t) { - DnsServer *s; - - assert(m); - - if (t == DNS_SERVER_SYSTEM) - while (m->dns_servers) { - s = m->dns_servers; - - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } - - if (t == DNS_SERVER_FALLBACK) - while (m->fallback_dns_servers) { - s = m->fallback_dns_servers; - - LIST_REMOVE(servers, m->fallback_dns_servers, s); - dns_server_unref(s); - } -} - int manager_is_own_hostname(Manager *m, const char *name) { int r; diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index 074ce6c..29b08cf 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -138,8 +138,6 @@ DnsScope* manager_find_scope(Manager *m, DnsPacket *p); void manager_verify_all(Manager *m); -void manager_flush_dns_servers(Manager *m, DnsServerType t); - DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); #define EXTRA_CMSG_SPACE 1024 -- 2.7.4