diff options
Diffstat (limited to 'src/resolve')
| -rw-r--r-- | src/resolve/resolved-manager.c | 275 | ||||
| -rw-r--r-- | src/resolve/resolved-manager.h | 2 | ||||
| -rw-r--r-- | src/resolve/resolved-resolv-conf.c | 306 | ||||
| -rw-r--r-- | src/resolve/resolved-resolv-conf.h | 27 | ||||
| -rw-r--r-- | src/resolve/resolved.c | 1 |
5 files changed, 335 insertions, 276 deletions
diff --git a/src/resolve/resolved-manager.c b/src/resolve/resolved-manager.c index c35379aa39..23806aa30b 100644 --- a/src/resolve/resolved-manager.c +++ b/src/resolve/resolved-manager.c @@ -21,7 +21,6 @@ #include <netinet/in.h> #include <poll.h> -#include <resolv.h> #include <sys/ioctl.h> #include "af-list.h" @@ -40,6 +39,7 @@ #include "resolved-conf.h" #include "resolved-llmnr.h" #include "resolved-manager.h" +#include "resolved-resolv-conf.h" #include "socket-util.h" #include "string-table.h" #include "string-util.h" @@ -579,279 +579,6 @@ Manager *manager_free(Manager *m) { return NULL; } -int manager_read_resolv_conf(Manager *m) { - _cleanup_fclose_ FILE *f = NULL; - struct stat st, own; - char line[LINE_MAX]; - DnsServer *s; - usec_t t; - int r; - - assert(m); - - /* Reads the system /etc/resolv.conf, if it exists and is not - * symlinked to our own resolv.conf instance */ - - if (!m->read_resolv_conf) - return 0; - - r = stat("/etc/resolv.conf", &st); - if (r < 0) { - if (errno == ENOENT) - r = 0; - else - r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); - goto clear; - } - - /* Have we already seen the file? */ - t = timespec_load(&st.st_mtim); - if (t == m->resolv_conf_mtime) - return 0; - - m->resolv_conf_mtime = t; - - /* Is it symlinked to our own file? */ - if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && - st.st_dev == own.st_dev && - st.st_ino == own.st_ino) { - r = 0; - goto clear; - } - - f = fopen("/etc/resolv.conf", "re"); - if (!f) { - if (errno == ENOENT) - r = 0; - else - r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); - goto clear; - } - - if (fstat(fileno(f), &st) < 0) { - r = log_error_errno(errno, "Failed to stat open file: %m"); - goto clear; - } - - manager_mark_dns_servers(m, DNS_SERVER_SYSTEM); - - FOREACH_LINE(line, f, r = -errno; goto clear) { - _cleanup_strv_free_ char **d = NULL; - const char *a; - char *l; - - truncate_nl(line); - - l = strstrip(line); - if (*l == '#' || *l == ';') - continue; - - a = first_word(l, "nameserver"); - 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); - - continue; - } - } - - 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 - * network managing implementations (like NetworkManager), - * that when connecting to a VPN place both the VPN DNS - * servers and the local ones in /etc/resolv.conf. Without - * resetting the DNS server to use back to the first entry we - * will continue to use the local one thus being unable to - * resolve VPN domains. */ - manager_set_dns_server(m, m->dns_servers); - - return 0; - -clear: - while (m->dns_servers) { - s = m->dns_servers; - - LIST_REMOVE(servers, m->dns_servers, s); - dns_server_unref(s); - } - - return r; -} - -static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { - _cleanup_free_ char *t = NULL; - int r; - - assert(s); - assert(f); - assert(count); - - r = in_addr_to_string(s->family, &s->address, &t); - if (r < 0) { - log_warning_errno(r, "Invalid DNS address. Ignoring: %m"); - return; - } - - if (*count == MAXNS) - fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); - (*count) ++; - - fprintf(f, "nameserver %s\n", t); -} - -static void write_resolv_conf_search( - const char *domain, - FILE *f, - unsigned *count, - unsigned *length) { - - assert(domain); - assert(f); - assert(length); - - if (*count >= MAXDNSRCH || - *length + strlen(domain) > 256) { - if (*count == MAXDNSRCH) - fputs(" # Too many search domains configured, remaining ones ignored.", f); - if (*length <= 256) - fputs(" # Total length of all search domains is too long, remaining ones ignored.", f); - - return; - } - - (*length) += strlen(domain); - (*count) ++; - - fputc(' ', f); - fputs(domain, f); -} - -static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { - Iterator i; - - fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" - "# Third party programs must not access this file directly, but\n" - "# only through the symlink at /etc/resolv.conf. To manage\n" - "# resolv.conf(5) in a different way, replace the symlink by a\n" - "# static file or a different symlink.\n\n", f); - - if (ordered_set_isempty(dns)) - fputs("# No DNS servers known.\n", f); - else { - unsigned count = 0; - DnsServer *s; - - ORDERED_SET_FOREACH(s, dns, i) - write_resolv_conf_server(s, f, &count); - } - - if (!ordered_set_isempty(domains)) { - unsigned length = 0, count = 0; - char *domain; - - fputs("search", f); - ORDERED_SET_FOREACH(domain, domains, i) - write_resolv_conf_search(domain, f, &count, &length); - fputs("\n", f); - } - - return fflush_and_check(f); -} - -int manager_write_resolv_conf(Manager *m) { - static const char path[] = "/run/systemd/resolve/resolv.conf"; - _cleanup_free_ char *temp_path = NULL; - _cleanup_fclose_ FILE *f = NULL; - _cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL; - DnsServer *s; - Iterator i; - Link *l; - int r; - - assert(m); - - /* Read the system /etc/resolv.conf first */ - manager_read_resolv_conf(m); - - /* Add the full list to a set, to filter out duplicates */ - dns = ordered_set_new(&dns_server_hash_ops); - if (!dns) - return -ENOMEM; - - domains = ordered_set_new(&dns_name_hash_ops); - if (!domains) - return -ENOMEM; - - /* First add the system-wide servers and domains */ - LIST_FOREACH(servers, s, m->dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - - /* Then, add the per-link servers and domains */ - HASHMAP_FOREACH(l, m->links, i) { - char **domain; - - LIST_FOREACH(servers, s, l->dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - - if (!l->unicast_scope) - continue; - - STRV_FOREACH(domain, l->unicast_scope->domains) { - r = ordered_set_put(domains, *domain); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - } - - /* If we found nothing, add the fallback servers */ - if (ordered_set_isempty(dns)) { - LIST_FOREACH(servers, s, m->fallback_dns_servers) { - r = ordered_set_put(dns, s); - if (r == -EEXIST) - continue; - if (r < 0) - return r; - } - } - - r = fopen_temporary_label(path, path, &f, &temp_path); - if (r < 0) - return r; - - fchmod(fileno(f), 0644); - - r = write_resolv_conf_contents(f, dns, domains); - if (r < 0) - goto fail; - - if (rename(temp_path, path) < 0) { - r = -errno; - goto fail; - } - - return 0; - -fail: - (void) unlink(path); - (void) unlink(temp_path); - return r; -} - int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) { _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL; union { diff --git a/src/resolve/resolved-manager.h b/src/resolve/resolved-manager.h index 29b08cf0e9..23ee1f6bc5 100644 --- a/src/resolve/resolved-manager.h +++ b/src/resolve/resolved-manager.h @@ -113,8 +113,6 @@ int manager_new(Manager **ret); Manager* manager_free(Manager *m); int manager_start(Manager *m); -int manager_read_resolv_conf(Manager *m); -int manager_write_resolv_conf(Manager *m); DnsServer *manager_set_dns_server(Manager *m, DnsServer *s); DnsServer *manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr); diff --git a/src/resolve/resolved-resolv-conf.c b/src/resolve/resolved-resolv-conf.c new file mode 100644 index 0000000000..5a6e3812df --- /dev/null +++ b/src/resolve/resolved-resolv-conf.c @@ -0,0 +1,306 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. + ***/ + +#include <resolv.h> + +#include "alloc-util.h" +#include "dns-domain.h" +#include "fd-util.h" +#include "fileio-label.h" +#include "fileio.h" +#include "ordered-set.h" +#include "resolved-conf.h" +#include "resolved-resolv-conf.h" +#include "string-util.h" +#include "strv.h" + +int manager_read_resolv_conf(Manager *m) { + _cleanup_fclose_ FILE *f = NULL; + struct stat st, own; + char line[LINE_MAX]; + DnsServer *s; + usec_t t; + int r; + + assert(m); + + /* Reads the system /etc/resolv.conf, if it exists and is not + * symlinked to our own resolv.conf instance */ + + if (!m->read_resolv_conf) + return 0; + + r = stat("/etc/resolv.conf", &st); + if (r < 0) { + if (errno == ENOENT) + r = 0; + else + r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + goto clear; + } + + /* Have we already seen the file? */ + t = timespec_load(&st.st_mtim); + if (t == m->resolv_conf_mtime) + return 0; + + m->resolv_conf_mtime = t; + + /* Is it symlinked to our own file? */ + if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 && + st.st_dev == own.st_dev && + st.st_ino == own.st_ino) { + r = 0; + goto clear; + } + + f = fopen("/etc/resolv.conf", "re"); + if (!f) { + if (errno == ENOENT) + r = 0; + else + r = log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m"); + goto clear; + } + + if (fstat(fileno(f), &st) < 0) { + r = log_error_errno(errno, "Failed to stat open file: %m"); + goto clear; + } + + manager_mark_dns_servers(m, DNS_SERVER_SYSTEM); + + FOREACH_LINE(line, f, r = -errno; goto clear) { + _cleanup_strv_free_ char **d = NULL; + const char *a; + char *l; + + truncate_nl(line); + + l = strstrip(line); + if (*l == '#' || *l == ';') + continue; + + a = first_word(l, "nameserver"); + 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); + + continue; + } + } + + 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 + * network managing implementations (like NetworkManager), + * that when connecting to a VPN place both the VPN DNS + * servers and the local ones in /etc/resolv.conf. Without + * resetting the DNS server to use back to the first entry we + * will continue to use the local one thus being unable to + * resolve VPN domains. */ + manager_set_dns_server(m, m->dns_servers); + + return 0; + +clear: + while (m->dns_servers) { + s = m->dns_servers; + + LIST_REMOVE(servers, m->dns_servers, s); + dns_server_unref(s); + } + + return r; +} + +static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) { + _cleanup_free_ char *t = NULL; + int r; + + assert(s); + assert(f); + assert(count); + + r = in_addr_to_string(s->family, &s->address, &t); + if (r < 0) { + log_warning_errno(r, "Invalid DNS address. Ignoring: %m"); + return; + } + + if (*count == MAXNS) + fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f); + (*count) ++; + + fprintf(f, "nameserver %s\n", t); +} + +static void write_resolv_conf_search( + const char *domain, + FILE *f, + unsigned *count, + unsigned *length) { + + assert(domain); + assert(f); + assert(length); + + if (*count >= MAXDNSRCH || + *length + strlen(domain) > 256) { + if (*count == MAXDNSRCH) + fputs(" # Too many search domains configured, remaining ones ignored.", f); + if (*length <= 256) + fputs(" # Total length of all search domains is too long, remaining ones ignored.", f); + + return; + } + + (*length) += strlen(domain); + (*count) ++; + + fputc(' ', f); + fputs(domain, f); +} + +static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) { + Iterator i; + + fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n" + "# Third party programs must not access this file directly, but\n" + "# only through the symlink at /etc/resolv.conf. To manage\n" + "# resolv.conf(5) in a different way, replace the symlink by a\n" + "# static file or a different symlink.\n\n", f); + + if (ordered_set_isempty(dns)) + fputs("# No DNS servers known.\n", f); + else { + unsigned count = 0; + DnsServer *s; + + ORDERED_SET_FOREACH(s, dns, i) + write_resolv_conf_server(s, f, &count); + } + + if (!ordered_set_isempty(domains)) { + unsigned length = 0, count = 0; + char *domain; + + fputs("search", f); + ORDERED_SET_FOREACH(domain, domains, i) + write_resolv_conf_search(domain, f, &count, &length); + fputs("\n", f); + } + + return fflush_and_check(f); +} + +int manager_write_resolv_conf(Manager *m) { + static const char path[] = "/run/systemd/resolve/resolv.conf"; + _cleanup_free_ char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + _cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL; + DnsServer *s; + Iterator i; + Link *l; + int r; + + assert(m); + + /* Read the system /etc/resolv.conf first */ + manager_read_resolv_conf(m); + + /* Add the full list to a set, to filter out duplicates */ + dns = ordered_set_new(&dns_server_hash_ops); + if (!dns) + return -ENOMEM; + + domains = ordered_set_new(&dns_name_hash_ops); + if (!domains) + return -ENOMEM; + + /* First add the system-wide servers and domains */ + LIST_FOREACH(servers, s, m->dns_servers) { + r = ordered_set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + /* Then, add the per-link servers and domains */ + HASHMAP_FOREACH(l, m->links, i) { + char **domain; + + LIST_FOREACH(servers, s, l->dns_servers) { + r = ordered_set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + if (!l->unicast_scope) + continue; + + STRV_FOREACH(domain, l->unicast_scope->domains) { + r = ordered_set_put(domains, *domain); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + /* If we found nothing, add the fallback servers */ + if (ordered_set_isempty(dns)) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = ordered_set_put(dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + r = fopen_temporary_label(path, path, &f, &temp_path); + if (r < 0) + return r; + + fchmod(fileno(f), 0644); + + r = write_resolv_conf_contents(f, dns, domains); + if (r < 0) + goto fail; + + if (rename(temp_path, path) < 0) { + r = -errno; + goto fail; + } + + return 0; + +fail: + (void) unlink(path); + (void) unlink(temp_path); + return r; +} diff --git a/src/resolve/resolved-resolv-conf.h b/src/resolve/resolved-resolv-conf.h new file mode 100644 index 0000000000..a3355e994b --- /dev/null +++ b/src/resolve/resolved-resolv-conf.h @@ -0,0 +1,27 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +#pragma once + +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include "resolved-manager.h" + +int manager_read_resolv_conf(Manager *m); +int manager_write_resolv_conf(Manager *m); diff --git a/src/resolve/resolved.c b/src/resolve/resolved.c index 7ba0546f4a..e07f49ce17 100644 --- a/src/resolve/resolved.c +++ b/src/resolve/resolved.c @@ -26,6 +26,7 @@ #include "mkdir.h" #include "resolved-conf.h" #include "resolved-manager.h" +#include "resolved-resolv-conf.h" #include "selinux-util.h" #include "signal-util.h" #include "user-util.h" |