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Merge pull request #8296 from poettering/resolvconf 

resolvconf(8) compat interface
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2018-03-12 17:27:39 +01:00 committed by GitHub
parent dace710c4a 2eee2088d2
commit 99eae076eb
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
10 changed files with 481 additions and 30 deletions
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2
man/rules/meson.build
View File

@ -614,7 +614,7 @@ manpages = [
'ENABLE_RANDOMSEED'],
['systemd-rc-local-generator', '8', [], ''],
['systemd-remount-fs.service', '8', ['systemd-remount-fs'], ''],
['systemd-resolve', '1', [], 'ENABLE_RESOLVE'],
['systemd-resolve', '1', ['resolvconf'], 'ENABLE_RESOLVE'],
['systemd-resolved.service', '8', ['systemd-resolved'], 'ENABLE_RESOLVE'],
['systemd-rfkill.service',
'8',

94
man/systemd-resolve.xml
View File

@ -47,7 +47,8 @@
<refnamediv>
<refname>systemd-resolve</refname>
<refpurpose>Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services</refpurpose>
<refname>resolvconf</refname>
<refpurpose>Resolve domain names, IPV4 and IPv6 addresses, DNS resource records, and services; introspect and reconfigure the DNS resolver</refpurpose>
</refnamediv>
<refsynopsisdiv>
@ -134,6 +135,18 @@
<command> --revert</command>
</cmdsynopsis>
<cmdsynopsis>
<command>resolvconf</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<command> -a <replaceable>INTERFACE</replaceable> &lt; <replaceable>FILE</replaceable></command>
</cmdsynopsis>
<cmdsynopsis>
<command>resolvconf</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<command> -d <replaceable>INTERFACE</replaceable></command>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1>
@ -399,6 +412,82 @@
</variablelist>
</refsect1>
<refsect1>
<title>Compatibility with <citerefentry><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry></title>
<para><command>systemd-resolve</command> is a multi-call binary. When invoked as <literal>resolvconf</literal>
(generally achieved by means of a symbolic link of this name to the <command>systemd-resolve</command> binary) it
is run in a limited <citerefentry><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry>
compatibility mode. It accepts mostly the same arguments and pushes all data into
<citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
similar to how <option>--set-dns=</option> and <option>--set-domain=</option> operate. Note that
<command>systemd-resolved.service</command> is the only supported backend, which is different from other
implementations of this command. Note that not all operations supported by other implementations are supported
natively. Specifically:</para>
<variablelist>
<varlistentry>
<term><option>-a</option></term>
<listitem><para>Registers per-interface DNS configuration data with
<command>systemd-resolved</command>. Expects a network interface name as only command line argument. Reads
<citerefentry><refentrytitle>resolv.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> compatible DNS
configuration data from its standard input. Relevant fields are <literal>nameserver</literal> and
<literal>domain</literal>/<literal>search</literal>. This command is mostly identical to invoking
<command>systemd-resolve</command> with a combination of <option>--set-dns=</option> and
<option>--set-domain=</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-d</option></term>
<listitem><para>Unregisters per-interface DNS configuration data with <command>systemd-resolved</command>. This
command is mostly identical to invoking <command>systemd-resolve</command> with
<option>--revert</option>.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-f</option></term>
<listitem><para>When specified <option>-a</option> and <option>-d</option> will not complain about missing
network interfaces and will silently execute no operation in that case.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-x</option></term>
<listitem><para>This switch for "exclusive" operation is supported only partially. It is mapped to an
additional configured search domain of <literal>~.</literal> — i.e. ensures that DNS traffic is preferably
routed to the DNS servers on this interface, unless there are other, more specific domains configured on other
interfaces.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-m</option></term>
<term><option>-p</option></term>
<listitem><para>These switches are not supported and are silently ignored.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>-u</option></term>
<term><option>-I</option></term>
<term><option>-i</option></term>
<term><option>-l</option></term>
<term><option>-R</option></term>
<term><option>-r</option></term>
<term><option>-v</option></term>
<term><option>-V</option></term>
<term><option>--enable-updates</option></term>
<term><option>--disable-updates</option></term>
<term><option>--are-updates-enabled</option></term>
<listitem><para>These switches are not supported and the command will fail if used.</para></listitem>
</varlistentry>
</variablelist>
<para>See <citerefentry><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry> for details on this command line options.</para>
</refsect1>
<refsect1>
<title>Examples</title>
@ -477,7 +566,8 @@ _443._tcp.fedoraproject.org IN TLSA 0 0 1 19400be5b7a31fb733917700789d2f0a2471c0
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-resolved.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.dnssd</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
<citerefentry><refentrytitle>systemd-networkd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>resolvconf</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>

4
meson.build
View File

@ -1632,6 +1632,10 @@ if conf.get('ENABLE_RESOLVE') == 1
install_rpath : rootlibexecdir,
install : true)
public_programs += [exe]
meson.add_install_script(meson_make_symlink,
join_paths(bindir, 'systemd-resolve'),
join_paths(rootsbindir, 'resolvconf'))
endif
if conf.get('ENABLE_LOGIND') == 1

7
src/resolve/meson.build
View File

@ -80,7 +80,12 @@ systemd_resolved_sources = files('''
resolved-etc-hosts.c
'''.split())
systemd_resolve_sources = files('resolve-tool.c')
systemd_resolve_sources = files('''
resolvconf-compat.c
resolvconf-compat.h
resolve-tool.c
resolve-tool.h
'''.split())
############################################################

312
src/resolve/resolvconf-compat.c Normal file
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@ -0,0 +1,312 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <getopt.h>
#include <net/if.h>
#include "alloc-util.h"
#include "def.h"
#include "dns-domain.h"
#include "extract-word.h"
#include "fileio.h"
#include "parse-util.h"
#include "resolvconf-compat.h"
#include "resolve-tool.h"
#include "resolved-def.h"
#include "string-util.h"
#include "strv.h"
static void resolvconf_help(void) {
printf("%1$s -a INTERFACE < FILE\n"
"%1$s -d INTERFACE\n"
"\n"
"Register DNS server and domain configuration with systemd-resolved.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
" -a Register per-interface DNS server and domain data\n"
" -d Unregister per-interface DNS server and domain data\n"
" -f Ignore if specified interface does not exist\n"
" -x Send DNS traffic preferably over this interface\n"
"\n"
"This is a compatibility alias for the systemd-resolve(1) tool, providing native\n"
"command line compatibility with the resolvconf(8) tool of various Linux\n"
"distributions and BSD systems. Some options supported by other implementations\n"
"are not supported and are ignored: -m, -p. Various options supported by other\n"
"implementations are not supported and will cause the invocation to fail: -u,\n"
"-I, -i, -l, -R, -r, -v, -V, --enable-updates, --disable-updates,\n"
"--updates-are-enabled.\n"
, program_invocation_short_name);
}
static int parse_nameserver(const char *string) {
int r;
assert(string);
for (;;) {
_cleanup_free_ char *word = NULL;
struct in_addr_data data, *n;
int ifindex = 0;
r = extract_first_word(&string, &word, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
r = in_addr_ifindex_from_string_auto(word, &data.family, &data.address, &ifindex);
if (r < 0)
return log_error_errno(r, "Failed to parse name server '%s': %m", word);
if (ifindex > 0 && ifindex != arg_ifindex) {
log_error("Name server interface '%s' does not match selected interface: %m", word);
return -EINVAL;
}
/* Some superficial filtering */
if (in_addr_is_null(data.family, &data.address))
continue;
if (data.family == AF_INET && data.address.in.s_addr == htobe32(INADDR_DNS_STUB)) /* resolved's own stub? */
continue;
n = reallocarray(arg_set_dns, arg_n_set_dns + 1, sizeof(struct in_addr_data));
if (!n)
return log_oom();
arg_set_dns = n;
arg_set_dns[arg_n_set_dns++] = data;
}
return 0;
}
static int parse_search_domain(const char *string) {
int r;
assert(string);
for (;;) {
_cleanup_free_ char *word = NULL;
r = extract_first_word(&string, &word, NULL, EXTRACT_QUOTES);
if (r < 0)
return r;
if (r == 0)
break;
r = dns_name_is_valid(word);
if (r < 0)
return log_error_errno(r, "Failed to validate specified domain '%s': %m", word);
if (r == 0) {
log_error("Domain not valid: %s", word);
return -EINVAL;
}
if (strv_push(&arg_set_domain, word) < 0)
return log_oom();
word = NULL;
}
return 0;
}
int resolvconf_parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_ENABLE_UPDATES,
ARG_DISABLE_UPDATES,
ARG_UPDATES_ARE_ENABLED,
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
/* The following are specific to Debian's original resolvconf */
{ "enable-updates", no_argument, NULL, ARG_ENABLE_UPDATES },
{ "disable-updates", no_argument, NULL, ARG_DISABLE_UPDATES },
{ "updates-are-enabled", no_argument, NULL, ARG_UPDATES_ARE_ENABLED },
{}
};
enum {
TYPE_REGULAR,
TYPE_PRIVATE, /* -p: Not supported, treated identically to TYPE_REGULAR */
TYPE_EXCLUSIVE, /* -x */
} type = TYPE_REGULAR;
const char *dot, *iface;
int c, r;
assert(argc >= 0);
assert(argv);
/* openresolv checks these environment variables */
if (getenv("IF_EXCLUSIVE"))
type = TYPE_EXCLUSIVE;
if (getenv("IF_PRIVATE"))
type = TYPE_PRIVATE; /* not actually supported */
arg_mode = _MODE_INVALID;
while ((c = getopt_long(argc, argv, "hadxpfm:uIi:l:Rr:vV", options, NULL)) >= 0)
switch(c) {
case 'h':
resolvconf_help();
return 0; /* done */;
case ARG_VERSION:
return version();
/* -a and -d is what everybody can agree on */
case 'a':
arg_mode = MODE_SET_LINK;
break;
case 'd':
arg_mode = MODE_REVERT_LINK;
break;
/* The exclusive/private/force stuff is an openresolv invention, we support in some skewed way */
case 'x':
type = TYPE_EXCLUSIVE;
break;
case 'p':
type = TYPE_PRIVATE; /* not actually supported */
break;
case 'f':
arg_ifindex_permissive = true;
break;
/* The metrics stuff is an openresolv invention we ignore (and don't really need) */
case 'm':
log_debug("Switch -%c ignored.", c);
break;
/* Everybody else can agree on the existance of -u but we don't support it. */
case 'u':
/* The following options are openresolv inventions we don't support. */
case 'I':
case 'i':
case 'l':
case 'R':
case 'r':
case 'v':
case 'V':
log_error("Switch -%c not supported.", c);
return -EINVAL;
/* The Debian resolvconf commands we don't support. */
case ARG_ENABLE_UPDATES:
log_error("Switch --enable-updates not supported.");
return -EINVAL;
case ARG_DISABLE_UPDATES:
log_error("Switch --disable-updates not supported.");
return -EINVAL;
case ARG_UPDATES_ARE_ENABLED:
log_error("Switch --updates-are-enabled not supported.");
return -EINVAL;
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
if (arg_mode == _MODE_INVALID) {
log_error("Expected either -a or -d on the command line.");
return -EINVAL;
}
if (optind+1 != argc) {
log_error("Expected interface name as argument.");
return -EINVAL;
}
dot = strchr(argv[optind], '.');
if (dot) {
iface = strndupa(argv[optind], dot - argv[optind]);
log_debug("Ignoring protocol specifier '%s'.", dot + 1);
} else
iface = argv[optind];
optind++;
if (parse_ifindex(iface, &arg_ifindex) < 0) {
int ifi;
ifi = if_nametoindex(iface);
if (ifi <= 0) {
if (errno == ENODEV && arg_ifindex_permissive) {
log_debug("Interface '%s' not found, but -f specified, ignoring.", iface);
return 0; /* done */
}
return log_error_errno(errno, "Unknown interface '%s': %m", iface);
}
arg_ifindex = ifi;
}
if (arg_mode == MODE_SET_LINK) {
unsigned n = 0;
for (;;) {
_cleanup_free_ char *line = NULL;
const char *a, *l;
r = read_line(stdin, LONG_LINE_MAX, &line);
if (r < 0)
return log_error_errno(r, "Failed to read from stdin: %m");
if (r == 0)
break;
n++;
l = strstrip(line);
if (IN_SET(*l, '#', ';', 0))
continue;
a = first_word(l, "nameserver");
if (a) {
(void) parse_nameserver(a);
continue;
}
a = first_word(l, "domain");
if (!a)
a = first_word(l, "search");
if (a) {
(void) parse_search_domain(a);
continue;
}
log_syntax(NULL, LOG_DEBUG, "stdin", n, 0, "Ignoring resolv.conf line: %s", l);
}
if (type == TYPE_EXCLUSIVE) {
/* If -x mode is selected, let's preferably route non-suffixed lookups to this interface. This
* somewhat matches the original -x behaviour */
r = strv_extend(&arg_set_domain, "~.");
if (r < 0)
return log_oom();
} else if (type == TYPE_PRIVATE)
log_debug("Private DNS server data not supported, ignoring.");
if (arg_n_set_dns == 0) {
log_error("No DNS servers specified, refusing operation.");
return -EINVAL;
}
}
return 1; /* work to do */
}

3
src/resolve/resolvconf-compat.h Normal file
View File

@ -0,0 +1,3 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
int resolvconf_parse_argv(int argc, char *argv[]);

53
src/resolve/resolve-tool.c
View File

@ -36,18 +36,21 @@
#include "netlink-util.h"
#include "pager.h"
#include "parse-util.h"
#include "resolvconf-compat.h"
#include "resolve-tool.h"
#include "resolved-def.h"
#include "resolved-dns-packet.h"
#include "strv.h"
#include "terminal-util.h"
static int arg_family = AF_UNSPEC;
static int arg_ifindex = 0;
int arg_ifindex = 0;
static uint16_t arg_type = 0;
static uint16_t arg_class = 0;
static bool arg_legend = true;
static uint64_t arg_flags = 0;
static bool arg_no_pager = false;
bool arg_ifindex_permissive = false; /* If true, don't generate an error if the specified interface index doesn't exist */
typedef enum ServiceFamily {
SERVICE_FAMILY_TCP,
@ -64,24 +67,11 @@ typedef enum RawType {
} RawType;
static RawType arg_raw = RAW_NONE;
static enum {
MODE_RESOLVE_HOST,
MODE_RESOLVE_RECORD,
MODE_RESOLVE_SERVICE,
MODE_RESOLVE_OPENPGP,
MODE_RESOLVE_TLSA,
MODE_STATISTICS,
MODE_RESET_STATISTICS,
MODE_FLUSH_CACHES,
MODE_RESET_SERVER_FEATURES,
MODE_STATUS,
MODE_SET_LINK,
MODE_REVERT_LINK,
} arg_mode = MODE_RESOLVE_HOST;
ExecutionMode arg_mode = MODE_RESOLVE_HOST;
static struct in_addr_data *arg_set_dns = NULL;
static size_t arg_n_set_dns = 0;
static char **arg_set_domain = NULL;
struct in_addr_data *arg_set_dns = NULL;
size_t arg_n_set_dns = 0;
char **arg_set_domain = NULL;
static char *arg_set_llmnr = NULL;
static char *arg_set_mdns = NULL;
static char *arg_set_dnssec = NULL;
@ -1609,6 +1599,9 @@ static int set_link(sd_bus *bus) {
if (q < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_LINK_BUSY))
goto is_managed;
if (arg_ifindex_permissive &&
sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_LINK))
return 0;
log_error_errno(q, "Failed to set DNS configuration: %s", bus_error_message(&error, q));
if (r == 0)
@ -1655,6 +1648,9 @@ static int set_link(sd_bus *bus) {
if (q < 0) {
if (sd_bus_error_has_name(&error, BUS_ERROR_LINK_BUSY))
goto is_managed;
if (arg_ifindex_permissive &&
sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_LINK))
return 0;
log_error_errno(q, "Failed to set domain configuration: %s", bus_error_message(&error, q));
if (r == 0)
@ -1777,8 +1773,13 @@ static int revert_link(sd_bus *bus) {
&error,
NULL,
"i", arg_ifindex);
if (r < 0)
if (r < 0) {
if (arg_ifindex_permissive &&
sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_LINK))
return 0;
return log_error_errno(r, "Failed to revert interface configuration: %s", bus_error_message(&error, r));
}
return 0;
}
@ -1815,7 +1816,7 @@ static void help_dns_classes(void) {
}
}
static void help(void) {
static void native_help(void) {
printf("%1$s [OPTIONS...] HOSTNAME|ADDRESS...\n"
"%1$s [OPTIONS...] --service [[NAME] TYPE] DOMAIN\n"
"%1$s [OPTIONS...] --openpgp EMAIL@DOMAIN...\n"
@ -1858,7 +1859,7 @@ static void help(void) {
, program_invocation_short_name);
}
static int parse_argv(int argc, char *argv[]) {
static int native_parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_LEGEND,
@ -1926,7 +1927,7 @@ static int parse_argv(int argc, char *argv[]) {
switch(c) {
case 'h':
help();
native_help();
return 0; /* done */;
case ARG_VERSION:
@ -2234,7 +2235,10 @@ int main(int argc, char **argv) {
log_parse_environment();
log_open();
r = parse_argv(argc, argv);
if (streq(program_invocation_short_name, "resolvconf"))
r = resolvconf_parse_argv(argc, argv);
else
r = native_parse_argv(argc, argv);
if (r <= 0)
goto finish;
@ -2435,6 +2439,9 @@ int main(int argc, char **argv) {
r = revert_link(bus);
break;
case _MODE_INVALID:
assert_not_reached("invalid mode");
}
finish:

30
src/resolve/resolve-tool.h Normal file
View File

@ -0,0 +1,30 @@
/* SPDX-License-Identifier: LGPL-2.1+ */
#include <in-addr-util.h>
#include <stdbool.h>
#include <sys/types.h>
extern int arg_ifindex;
extern bool arg_ifindex_permissive;
typedef enum ExecutionMode {
MODE_RESOLVE_HOST,
MODE_RESOLVE_RECORD,
MODE_RESOLVE_SERVICE,
MODE_RESOLVE_OPENPGP,
MODE_RESOLVE_TLSA,
MODE_STATISTICS,
MODE_RESET_STATISTICS,
MODE_FLUSH_CACHES,
MODE_RESET_SERVER_FEATURES,
MODE_STATUS,
MODE_SET_LINK,
MODE_REVERT_LINK,
_MODE_INVALID = -1,
} ExecutionMode;
extern ExecutionMode arg_mode;
extern struct in_addr_data *arg_set_dns;
extern size_t arg_n_set_dns;
extern char **arg_set_domain;

3
src/resolve/resolved-def.h
View File

@ -41,3 +41,6 @@
#define SD_RESOLVED_PROTOCOLS_ALL (SD_RESOLVED_MDNS|SD_RESOLVED_LLMNR|SD_RESOLVED_DNS)
#define SD_RESOLVED_QUERY_TIMEOUT_USEC (120 * USEC_PER_SEC)
/* 127.0.0.53 in native endian */
#define INADDR_DNS_STUB ((in_addr_t) 0x7f000035U)

3
src/resolve/resolved-dns-stub.h
View File

@ -22,8 +22,5 @@
#include "resolved-manager.h"
/* 127.0.0.53 in native endian */
#define INADDR_DNS_STUB ((in_addr_t) 0x7f000035U)
void manager_dns_stub_stop(Manager *m);
int manager_dns_stub_start(Manager *m);