libvirt/src/util/dnsmasq.c

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/*
* Copyright (C) 2007-2011 Red Hat, Inc.
* Copyright (C) 2010 Satoru SATOH <satoru.satoh@gmail.com>
*
* This library 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.
*
* This library 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 this library. If not, see
* <http://www.gnu.org/licenses/>.
*
* Based on iptables.c
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <limits.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <signal.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
#include "internal.h"
#include "datatypes.h"
#include "dnsmasq.h"
#include "util.h"
#include "memory.h"
#include "virterror_internal.h"
#include "logging.h"
#include "virfile.h"
#define VIR_FROM_THIS VIR_FROM_NETWORK
#define DNSMASQ_HOSTSFILE_SUFFIX "hostsfile"
#define DNSMASQ_ADDNHOSTSFILE_SUFFIX "addnhosts"
static void
dhcphostFree(dnsmasqDhcpHost *host)
{
VIR_FREE(host->host);
}
static void
addnhostFree(dnsmasqAddnHost *host)
{
int i;
for (i = 0; i < host->nhostnames; i++)
VIR_FREE(host->hostnames[i]);
VIR_FREE(host->hostnames);
VIR_FREE(host->ip);
}
static void
addnhostsFree(dnsmasqAddnHostsfile *addnhostsfile)
{
unsigned int i;
if (addnhostsfile->hosts) {
for (i = 0; i < addnhostsfile->nhosts; i++)
addnhostFree(&addnhostsfile->hosts[i]);
VIR_FREE(addnhostsfile->hosts);
addnhostsfile->nhosts = 0;
}
VIR_FREE(addnhostsfile->path);
VIR_FREE(addnhostsfile);
}
static int
addnhostsAdd(dnsmasqAddnHostsfile *addnhostsfile,
virSocketAddr *ip,
const char *name)
{
char *ipstr = NULL;
int idx = -1;
int i;
if (!(ipstr = virSocketAddrFormat(ip)))
return -1;
for (i = 0; i < addnhostsfile->nhosts; i++) {
if (STREQ((const char *)addnhostsfile->hosts[i].ip, (const char *)ipstr)) {
idx = i;
break;
}
}
if (idx < 0) {
if (VIR_REALLOC_N(addnhostsfile->hosts, addnhostsfile->nhosts + 1) < 0)
goto alloc_error;
idx = addnhostsfile->nhosts;
if (VIR_ALLOC(addnhostsfile->hosts[idx].hostnames) < 0)
goto alloc_error;
if (virAsprintf(&addnhostsfile->hosts[idx].ip, "%s", ipstr) < 0)
goto alloc_error;
addnhostsfile->hosts[idx].nhostnames = 0;
addnhostsfile->nhosts++;
}
if (VIR_REALLOC_N(addnhostsfile->hosts[idx].hostnames, addnhostsfile->hosts[idx].nhostnames + 1) < 0)
goto alloc_error;
if (virAsprintf(&addnhostsfile->hosts[idx].hostnames[addnhostsfile->hosts[idx].nhostnames], "%s", name) < 0)
goto alloc_error;
VIR_FREE(ipstr);
addnhostsfile->hosts[idx].nhostnames++;
return 0;
alloc_error:
virReportOOMError();
VIR_FREE(ipstr);
return -1;
}
static dnsmasqAddnHostsfile *
addnhostsNew(const char *name,
const char *config_dir)
{
dnsmasqAddnHostsfile *addnhostsfile;
if (VIR_ALLOC(addnhostsfile) < 0) {
virReportOOMError();
return NULL;
}
addnhostsfile->hosts = NULL;
addnhostsfile->nhosts = 0;
if (virAsprintf(&addnhostsfile->path, "%s/%s.%s", config_dir, name,
DNSMASQ_ADDNHOSTSFILE_SUFFIX) < 0) {
virReportOOMError();
goto error;
}
return addnhostsfile;
error:
addnhostsFree(addnhostsfile);
return NULL;
}
static int
addnhostsWrite(const char *path,
dnsmasqAddnHost *hosts,
unsigned int nhosts)
{
char *tmp;
FILE *f;
bool istmp = true;
unsigned int i, ii;
int rc = 0;
if (nhosts == 0)
return rc;
if (virAsprintf(&tmp, "%s.new", path) < 0)
return -ENOMEM;
if (!(f = fopen(tmp, "w"))) {
istmp = false;
if (!(f = fopen(path, "w"))) {
rc = -errno;
goto cleanup;
}
}
for (i = 0; i < nhosts; i++) {
if (fputs(hosts[i].ip, f) == EOF || fputc('\t', f) == EOF) {
rc = -errno;
VIR_FORCE_FCLOSE(f);
if (istmp)
unlink(tmp);
goto cleanup;
}
for (ii = 0; ii < hosts[i].nhostnames; ii++) {
if (fputs(hosts[i].hostnames[ii], f) == EOF || fputc('\t', f) == EOF) {
rc = -errno;
VIR_FORCE_FCLOSE(f);
if (istmp)
unlink(tmp);
goto cleanup;
}
}
if (fputc('\n', f) == EOF) {
rc = -errno;
VIR_FORCE_FCLOSE(f);
if (istmp)
unlink(tmp);
goto cleanup;
}
}
if (VIR_FCLOSE(f) == EOF) {
rc = -errno;
goto cleanup;
}
if (istmp && rename(tmp, path) < 0) {
rc = -errno;
unlink(tmp);
goto cleanup;
}
cleanup:
VIR_FREE(tmp);
return rc;
}
static int
addnhostsSave(dnsmasqAddnHostsfile *addnhostsfile)
{
int err = addnhostsWrite(addnhostsfile->path, addnhostsfile->hosts,
addnhostsfile->nhosts);
if (err < 0) {
virReportSystemError(-err, _("cannot write config file '%s'"),
addnhostsfile->path);
return -1;
}
return 0;
}
static int
genericFileDelete(char *path)
{
if (!virFileExists(path))
return 0;
if (unlink(path) < 0) {
virReportSystemError(errno, _("cannot remove config file '%s'"),
path);
return -1;
}
return 0;
}
static void
hostsfileFree(dnsmasqHostsfile *hostsfile)
{
unsigned int i;
if (hostsfile->hosts) {
for (i = 0; i < hostsfile->nhosts; i++)
dhcphostFree(&hostsfile->hosts[i]);
VIR_FREE(hostsfile->hosts);
hostsfile->nhosts = 0;
}
VIR_FREE(hostsfile->path);
VIR_FREE(hostsfile);
}
static int
hostsfileAdd(dnsmasqHostsfile *hostsfile,
const char *mac,
virSocketAddr *ip,
const char *name)
{
char *ipstr = NULL;
if (VIR_REALLOC_N(hostsfile->hosts, hostsfile->nhosts + 1) < 0)
goto alloc_error;
if (!(ipstr = virSocketAddrFormat(ip)))
return -1;
if (name) {
if (virAsprintf(&hostsfile->hosts[hostsfile->nhosts].host, "%s,%s,%s",
mac, ipstr, name) < 0) {
goto alloc_error;
}
} else {
if (virAsprintf(&hostsfile->hosts[hostsfile->nhosts].host, "%s,%s",
mac, ipstr) < 0) {
goto alloc_error;
}
}
VIR_FREE(ipstr);
hostsfile->nhosts++;
return 0;
alloc_error:
virReportOOMError();
VIR_FREE(ipstr);
return -1;
}
static dnsmasqHostsfile *
hostsfileNew(const char *name,
const char *config_dir)
{
dnsmasqHostsfile *hostsfile;
if (VIR_ALLOC(hostsfile) < 0) {
virReportOOMError();
return NULL;
}
hostsfile->hosts = NULL;
hostsfile->nhosts = 0;
if (virAsprintf(&hostsfile->path, "%s/%s.%s", config_dir, name,
DNSMASQ_HOSTSFILE_SUFFIX) < 0) {
virReportOOMError();
goto error;
}
return hostsfile;
error:
hostsfileFree(hostsfile);
return NULL;
}
static int
hostsfileWrite(const char *path,
dnsmasqDhcpHost *hosts,
unsigned int nhosts)
{
char *tmp;
FILE *f;
bool istmp = true;
unsigned int i;
int rc = 0;
if (nhosts == 0)
return rc;
if (virAsprintf(&tmp, "%s.new", path) < 0)
return -ENOMEM;
if (!(f = fopen(tmp, "w"))) {
istmp = false;
if (!(f = fopen(path, "w"))) {
rc = -errno;
goto cleanup;
}
}
for (i = 0; i < nhosts; i++) {
if (fputs(hosts[i].host, f) == EOF || fputc('\n', f) == EOF) {
rc = -errno;
VIR_FORCE_FCLOSE(f);
if (istmp)
unlink(tmp);
goto cleanup;
}
}
if (VIR_FCLOSE(f) == EOF) {
rc = -errno;
goto cleanup;
}
if (istmp && rename(tmp, path) < 0) {
rc = -errno;
unlink(tmp);
goto cleanup;
}
cleanup:
VIR_FREE(tmp);
return rc;
}
static int
hostsfileSave(dnsmasqHostsfile *hostsfile)
{
int err = hostsfileWrite(hostsfile->path, hostsfile->hosts,
hostsfile->nhosts);
if (err < 0) {
virReportSystemError(-err, _("cannot write config file '%s'"),
hostsfile->path);
return -1;
}
return 0;
}
/**
* dnsmasqContextNew:
*
* Create a new Dnsmasq context
*
* Returns a pointer to the new structure or NULL in case of error
*/
dnsmasqContext *
dnsmasqContextNew(const char *network_name,
const char *config_dir)
{
dnsmasqContext *ctx;
if (VIR_ALLOC(ctx) < 0) {
virReportOOMError();
return NULL;
}
network: Fix dnsmasq hostsfile creation logic and related tests networkSaveDnsmasqHostsfile was added in 8fa9c2214247 (Apr 2010). It has a force flag. If the dnsmasq hostsfile already exists force needs to be true to overwrite it. networkBuildDnsmasqArgv sets force to false, networkDefine sets it to true. This results in the hostsfile being written only in networkDefine in the common case. If no error occurred networkSaveDnsmasqHostsfile returns true and networkBuildDnsmasqArgv adds the --dhcp-hostsfile to the dnsmasq command line. networkSaveDnsmasqHostsfile was changed in 89ae9849f744 (24 Jun 2011) to return a new dnsmasqContext instead of reusing one. This change broke the logic of the force flag as now networkSaveDnsmasqHostsfile returns NULL on error, but the early return -- if force was not set and the hostsfile exists -- returns 0. This turned the early return in an error case and networkBuildDnsmasqArgv didn't add the --dhcp-hostsfile option anymore if the hostsfile already exists. It did because networkDefine created the hostsfile already. Then 9d4e2845d498 fixed the return 0 case in networkSaveDnsmasqHostsfile but didn't apply the force option correctly to the new addnhosts file. Now force doesn't control an early return anymore, but influences the handling of the hostsfile context creation and dnsmasqSave is always called now. This commit also added test cases that reveal several problems. First, the tests now calls functions that try to write the dnsmasq config files to disk. If someone runs this tests as root this might overwrite actively used dnsmasq config files, this is a no-go. Also the tests depend on configure --localstatedir, this needs to be fixed as well, because it makes the tests fail when localstatedir is different from /var. This patch does several things to fix this: 1) Move dnsmasqContext creation and saving out of networkBuildDnsmasqArgv to the caller to separate the command line generation from the config file writing. This makes the command line generation testable without the risk of interfering with system files, because the tests just don't call dnsmasqSave. 2) This refactoring of networkSaveDnsmasqHostsfile makes the force flag useless as the saving happens somewhere else now. This fixes the wrong usage of the force flag in combination with then newly added addnhosts file by removing the force flag. 3) Adapt the wrong test cases to the correct behavior, by adding the missing --dhcp-hostsfile option. Both affected tests contain DHCP host elements but missed the necessary --dhcp-hostsfile option. 4) Rename networkSaveDnsmasqHostsfile to networkBuildDnsmasqHostsfile, because it doesn't save the dnsmasqContext anymore. 5) Move all directory creations in dnsmasq context handling code from the *New functions to dnsmasqSave to avoid directory creations in system paths in the test cases. 6) Now that networkBuildDnsmasqArgv doesn't create the dnsmasqContext anymore the test case can create one with the localstatedir that is expected by the tests instead of the configure --localstatedir given one.
2011-06-28 11:07:59 +00:00
if (!(ctx->config_dir = strdup(config_dir))) {
virReportOOMError();
goto error;
}
if (!(ctx->hostsfile = hostsfileNew(network_name, config_dir)))
goto error;
if (!(ctx->addnhostsfile = addnhostsNew(network_name, config_dir)))
goto error;
return ctx;
error:
dnsmasqContextFree(ctx);
return NULL;
}
/**
* dnsmasqContextFree:
* @ctx: pointer to the dnsmasq context
*
* Free the resources associated with a dnsmasq context
*/
void
dnsmasqContextFree(dnsmasqContext *ctx)
{
if (!ctx)
return;
network: Fix dnsmasq hostsfile creation logic and related tests networkSaveDnsmasqHostsfile was added in 8fa9c2214247 (Apr 2010). It has a force flag. If the dnsmasq hostsfile already exists force needs to be true to overwrite it. networkBuildDnsmasqArgv sets force to false, networkDefine sets it to true. This results in the hostsfile being written only in networkDefine in the common case. If no error occurred networkSaveDnsmasqHostsfile returns true and networkBuildDnsmasqArgv adds the --dhcp-hostsfile to the dnsmasq command line. networkSaveDnsmasqHostsfile was changed in 89ae9849f744 (24 Jun 2011) to return a new dnsmasqContext instead of reusing one. This change broke the logic of the force flag as now networkSaveDnsmasqHostsfile returns NULL on error, but the early return -- if force was not set and the hostsfile exists -- returns 0. This turned the early return in an error case and networkBuildDnsmasqArgv didn't add the --dhcp-hostsfile option anymore if the hostsfile already exists. It did because networkDefine created the hostsfile already. Then 9d4e2845d498 fixed the return 0 case in networkSaveDnsmasqHostsfile but didn't apply the force option correctly to the new addnhosts file. Now force doesn't control an early return anymore, but influences the handling of the hostsfile context creation and dnsmasqSave is always called now. This commit also added test cases that reveal several problems. First, the tests now calls functions that try to write the dnsmasq config files to disk. If someone runs this tests as root this might overwrite actively used dnsmasq config files, this is a no-go. Also the tests depend on configure --localstatedir, this needs to be fixed as well, because it makes the tests fail when localstatedir is different from /var. This patch does several things to fix this: 1) Move dnsmasqContext creation and saving out of networkBuildDnsmasqArgv to the caller to separate the command line generation from the config file writing. This makes the command line generation testable without the risk of interfering with system files, because the tests just don't call dnsmasqSave. 2) This refactoring of networkSaveDnsmasqHostsfile makes the force flag useless as the saving happens somewhere else now. This fixes the wrong usage of the force flag in combination with then newly added addnhosts file by removing the force flag. 3) Adapt the wrong test cases to the correct behavior, by adding the missing --dhcp-hostsfile option. Both affected tests contain DHCP host elements but missed the necessary --dhcp-hostsfile option. 4) Rename networkSaveDnsmasqHostsfile to networkBuildDnsmasqHostsfile, because it doesn't save the dnsmasqContext anymore. 5) Move all directory creations in dnsmasq context handling code from the *New functions to dnsmasqSave to avoid directory creations in system paths in the test cases. 6) Now that networkBuildDnsmasqArgv doesn't create the dnsmasqContext anymore the test case can create one with the localstatedir that is expected by the tests instead of the configure --localstatedir given one.
2011-06-28 11:07:59 +00:00
VIR_FREE(ctx->config_dir);
if (ctx->hostsfile)
hostsfileFree(ctx->hostsfile);
if (ctx->addnhostsfile)
addnhostsFree(ctx->addnhostsfile);
VIR_FREE(ctx);
}
/**
* dnsmasqAddDhcpHost:
* @ctx: pointer to the dnsmasq context for each network
* @mac: pointer to the string contains mac address of the host
* @ip: pointer to the socket address contains ip of the host
* @name: pointer to the string contains hostname of the host or NULL
*
* Add dhcp-host entry.
*/
int
dnsmasqAddDhcpHost(dnsmasqContext *ctx,
const char *mac,
virSocketAddr *ip,
const char *name)
{
return hostsfileAdd(ctx->hostsfile, mac, ip, name);
}
/*
* dnsmasqAddHost:
* @ctx: pointer to the dnsmasq context for each network
* @ip: pointer to the socket address contains ip of the host
* @name: pointer to the string contains hostname of the host
*
* Add additional host entry.
*/
int
dnsmasqAddHost(dnsmasqContext *ctx,
virSocketAddr *ip,
const char *name)
{
return addnhostsAdd(ctx->addnhostsfile, ip, name);
}
/**
* dnsmasqSave:
* @ctx: pointer to the dnsmasq context for each network
*
* Saves all the configurations associated with a context to disk.
*/
int
dnsmasqSave(const dnsmasqContext *ctx)
{
int ret = 0;
if (virFileMakePath(ctx->config_dir) < 0) {
virReportSystemError(errno, _("cannot create config directory '%s'"),
network: Fix dnsmasq hostsfile creation logic and related tests networkSaveDnsmasqHostsfile was added in 8fa9c2214247 (Apr 2010). It has a force flag. If the dnsmasq hostsfile already exists force needs to be true to overwrite it. networkBuildDnsmasqArgv sets force to false, networkDefine sets it to true. This results in the hostsfile being written only in networkDefine in the common case. If no error occurred networkSaveDnsmasqHostsfile returns true and networkBuildDnsmasqArgv adds the --dhcp-hostsfile to the dnsmasq command line. networkSaveDnsmasqHostsfile was changed in 89ae9849f744 (24 Jun 2011) to return a new dnsmasqContext instead of reusing one. This change broke the logic of the force flag as now networkSaveDnsmasqHostsfile returns NULL on error, but the early return -- if force was not set and the hostsfile exists -- returns 0. This turned the early return in an error case and networkBuildDnsmasqArgv didn't add the --dhcp-hostsfile option anymore if the hostsfile already exists. It did because networkDefine created the hostsfile already. Then 9d4e2845d498 fixed the return 0 case in networkSaveDnsmasqHostsfile but didn't apply the force option correctly to the new addnhosts file. Now force doesn't control an early return anymore, but influences the handling of the hostsfile context creation and dnsmasqSave is always called now. This commit also added test cases that reveal several problems. First, the tests now calls functions that try to write the dnsmasq config files to disk. If someone runs this tests as root this might overwrite actively used dnsmasq config files, this is a no-go. Also the tests depend on configure --localstatedir, this needs to be fixed as well, because it makes the tests fail when localstatedir is different from /var. This patch does several things to fix this: 1) Move dnsmasqContext creation and saving out of networkBuildDnsmasqArgv to the caller to separate the command line generation from the config file writing. This makes the command line generation testable without the risk of interfering with system files, because the tests just don't call dnsmasqSave. 2) This refactoring of networkSaveDnsmasqHostsfile makes the force flag useless as the saving happens somewhere else now. This fixes the wrong usage of the force flag in combination with then newly added addnhosts file by removing the force flag. 3) Adapt the wrong test cases to the correct behavior, by adding the missing --dhcp-hostsfile option. Both affected tests contain DHCP host elements but missed the necessary --dhcp-hostsfile option. 4) Rename networkSaveDnsmasqHostsfile to networkBuildDnsmasqHostsfile, because it doesn't save the dnsmasqContext anymore. 5) Move all directory creations in dnsmasq context handling code from the *New functions to dnsmasqSave to avoid directory creations in system paths in the test cases. 6) Now that networkBuildDnsmasqArgv doesn't create the dnsmasqContext anymore the test case can create one with the localstatedir that is expected by the tests instead of the configure --localstatedir given one.
2011-06-28 11:07:59 +00:00
ctx->config_dir);
return -1;
}
if (ctx->hostsfile)
ret = hostsfileSave(ctx->hostsfile);
if (ret == 0) {
if (ctx->addnhostsfile)
ret = addnhostsSave(ctx->addnhostsfile);
}
return ret;
}
/**
* dnsmasqDelete:
* @ctx: pointer to the dnsmasq context for each network
*
* Delete all the configuration files associated with a context.
*/
int
dnsmasqDelete(const dnsmasqContext *ctx)
{
int ret = 0;
if (ctx->hostsfile)
ret = genericFileDelete(ctx->hostsfile->path);
if (ctx->addnhostsfile)
ret = genericFileDelete(ctx->addnhostsfile->path);
return ret;
}
/**
* dnsmasqReload:
* @pid: the pid of the target dnsmasq process
*
* Reloads all the configurations associated to a context
*/
int
dnsmasqReload(pid_t pid ATTRIBUTE_UNUSED)
{
#ifndef WIN32
if (kill(pid, SIGHUP) != 0) {
virReportSystemError(errno,
_("Failed to make dnsmasq (PID: %d) reload config files."),
pid);
return -1;
}
#endif /* WIN32 */
return 0;
}