* derivatives without specific, written prior permission.
*/
+#include <config.h>
#include "dhcp-client.h"
#include <arpa/inet.h>
#include <assert.h>
#include <limits.h>
#include <stdlib.h>
#include <string.h>
+#include <sys/types.h>
#include <time.h>
+#include <unistd.h>
#include "buffer.h"
#include "csum.h"
#include "dhcp.h"
bool (*validate_offer)(const struct dhcp_msg *, void *aux),
void *aux, struct dhclient **cli_)
{
- struct in_addr any = { INADDR_ANY };
struct dhclient *cli;
struct netdev *netdev;
int error;
return error;
}
- error = netdev_set_in4(netdev, any, any);
+ error = netdev_turn_flags_on(netdev, NETDEV_UP, false);
if (error) {
- VLOG_ERR("could not remove IPv4 address from %s network device: %s",
+ VLOG_ERR("could not bring %s device up: %s",
netdev_name, strerror(error));
netdev_close(netdev);
return error;
{
state_transition(cli, requested_ip ? S_INIT_REBOOT : S_INIT);
cli->ipaddr = requested_ip;
- cli->changed = true;
cli->min_timeout = 0;
cli->init_delay = 0;
}
return dhclient_is_bound(cli) ? cli->netmask : 0;
}
+/* If 'cli' is bound to an IP address and 'cli' has a default gateway, returns
+ * that default gateway; otherwise, returns 0. */
+uint32_t
+dhclient_get_router(const struct dhclient *cli)
+{
+ return dhclient_is_bound(cli) ? cli->router : 0;
+}
+
/* If 'cli' is bound to an IP address, returns the DHCP message that was
* received to obtain that IP address (so that the caller can obtain additional
* options from it). Otherwise, returns a null pointer. */
{
return dhclient_is_bound(cli) ? cli->binding : NULL;
}
+
+/* Configures the network device backing 'cli' to the network address and other
+ * parameters obtained via DHCP. If no address is bound on 'cli', removes any
+ * configured address from 'cli'.
+ *
+ * To use a dhclient as a regular DHCP client that binds and unbinds from IP
+ * addresses in the usual fashion, call this function after dhclient_run() if
+ * anything has changed, like so:
+ *
+ * dhclient_run(cli);
+ * if (dhclient_changed(cli)) {
+ * dhclient_configure_netdev(cli);
+ * }
+ *
+ */
+int
+dhclient_configure_netdev(struct dhclient *cli)
+{
+ struct in_addr addr = { dhclient_get_ip(cli) };
+ struct in_addr mask = { dhclient_get_netmask(cli) };
+ struct in_addr router = { dhclient_get_router(cli) };
+ int error;
+
+ error = netdev_set_in4(cli->netdev, addr, mask);
+ if (error) {
+ VLOG_ERR("could not set %s address "IP_FMT"/"IP_FMT": %s",
+ netdev_get_name(cli->netdev),
+ IP_ARGS(&addr.s_addr), IP_ARGS(&mask.s_addr),
+ strerror(error));
+ }
+
+ if (!error && router.s_addr) {
+ error = netdev_add_router(cli->netdev, router);
+ if (error) {
+ VLOG_ERR("failed to add default route to "IP_FMT" on %s: %s",
+ IP_ARGS(&router), netdev_get_name(cli->netdev),
+ strerror(error));
+ }
+ }
+
+ return error;
+}
+
+/* If 'cli' is bound and the binding includes DNS domain parameters, updates
+ * /etc/resolv.conf will be updated to match the received parameters. Returns
+ * 0 if successful, otherwise a positive errno value. */
+int
+dhclient_update_resolv_conf(struct dhclient *cli)
+{
+ uint32_t dns_server;
+ char *domain_name;
+ bool has_domain_name;
+ char new_name[128];
+ FILE *old, *new;
+ int i;
+
+ if (!dhclient_is_bound(cli)) {
+ return 0;
+ }
+ if (!dhcp_msg_get_ip(cli->binding, DHCP_CODE_DNS_SERVER, 0, &dns_server)) {
+ VLOG_DBG("binding does not include any DNS servers");
+ return 0;
+ }
+
+ sprintf(new_name, "/etc/resolv.conf.tmp%ld", (long int) getpid());
+ new = fopen(new_name, "w");
+ if (!new) {
+ VLOG_WARN("%s: create: %s", new_name, strerror(errno));
+ return errno;
+ }
+
+ domain_name = dhcp_msg_get_string(cli->binding, DHCP_CODE_DOMAIN_NAME);
+ has_domain_name = domain_name != NULL;
+ if (domain_name) {
+ if (strspn(domain_name, "-_.0123456789abcdefghijklmnopqrstuvwxyz"
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ") == strlen(domain_name)) {
+ fprintf(new, "domain %s\n", domain_name);
+ } else {
+ VLOG_WARN("ignoring invalid domain name %s", domain_name);
+ has_domain_name = false;
+ }
+ } else {
+ VLOG_DBG("binding does not include domain name");
+ }
+ free(domain_name);
+
+ for (i = 0; dhcp_msg_get_ip(cli->binding, DHCP_CODE_DNS_SERVER,
+ i, &dns_server); i++) {
+ fprintf(new, "nameserver "IP_FMT"\n", IP_ARGS(&dns_server));
+ }
+
+ old = fopen("/etc/resolv.conf", "r");
+ if (old) {
+ char line[128];
+
+ while (fgets(line, sizeof line, old)) {
+ char *kw = xmemdup0(line, strcspn(line, " \t\r\n"));
+ if (strcmp(kw, "nameserver")
+ && (!has_domain_name
+ || (strcmp(kw, "domain") && strcmp(kw, "search")))) {
+ fputs(line, new);
+ }
+ free(kw);
+ }
+ fclose(old);
+ } else {
+ VLOG_DBG("/etc/resolv.conf: open: %s", strerror(errno));
+ }
+
+ if (fclose(new) < 0) {
+ VLOG_WARN("%s: close: %s", new_name, strerror(errno));
+ return errno;
+ }
+
+ if (rename(new_name, "/etc/resolv.conf") < 0) {
+ VLOG_WARN("failed to rename %s to /etc/resolv.conf: %s",
+ new_name, strerror(errno));
+ return errno;
+ }
+
+ return 0;
+}
\f
/* DHCP protocol. */
if (msg->type < 0 || msg->type > 31 || !((1u << msg->type) & msgs)) {
VLOG_DBG("received unexpected %s in %s state: %s",
dhcp_type_name(msg->type), state_name(cli->state),
- dhcp_msg_to_string(msg, &cli->s));
+ dhcp_msg_to_string(msg, false, &cli->s));
} else if (msg->xid != cli->xid) {
VLOG_DBG("ignoring %s with xid != %08"PRIx32" in %s state: %s",
dhcp_type_name(msg->type), msg->xid,
- state_name(cli->state), dhcp_msg_to_string(msg, &cli->s));
+ state_name(cli->state),
+ dhcp_msg_to_string(msg, false, &cli->s));
} else {
return true;
}
{
uint32_t lease, netmask;
if (!dhcp_msg_get_secs(msg, DHCP_CODE_LEASE_TIME, 0, &lease)) {
- VLOG_WARN("%s lacks lease time: %s",
- dhcp_type_name(msg->type), dhcp_msg_to_string(msg, &cli->s));
+ VLOG_WARN("%s lacks lease time: %s", dhcp_type_name(msg->type),
+ dhcp_msg_to_string(msg, false, &cli->s));
} else if (!dhcp_msg_get_ip(msg, DHCP_CODE_SUBNET_MASK, 0, &netmask)) {
- VLOG_WARN("%s lacks netmask: %s",
- dhcp_type_name(msg->type), dhcp_msg_to_string(msg, &cli->s));
+ VLOG_WARN("%s lacks netmask: %s", dhcp_type_name(msg->type),
+ dhcp_msg_to_string(msg, false, &cli->s));
} else if (lease < MIN_ACCEPTABLE_LEASE) {
VLOG_WARN("Ignoring %s with %"PRIu32"-second lease time: %s",
dhcp_type_name(msg->type), lease,
- dhcp_msg_to_string(msg, &cli->s));
+ dhcp_msg_to_string(msg, false, &cli->s));
} else if (cli->validate_offer && !cli->validate_offer(msg, cli->aux)) {
VLOG_DBG("client validation hook refused offer: %s",
- dhcp_msg_to_string(msg, &cli->s));
+ dhcp_msg_to_string(msg, false, &cli->s));
} else {
return true;
}
if (!dhcp_msg_get_ip(&msg, DHCP_CODE_SERVER_IDENTIFIER,
0, &cli->server_ip)) {
VLOG_WARN("DHCPOFFER lacks server identifier: %s",
- dhcp_msg_to_string(&msg, &cli->s));
+ dhcp_msg_to_string(&msg, false, &cli->s));
continue;
}
- VLOG_DBG("accepting DHCPOFFER: %s", dhcp_msg_to_string(&msg, &cli->s));
+ VLOG_DBG("accepting DHCPOFFER: %s",
+ dhcp_msg_to_string(&msg, false, &cli->s));
cli->ipaddr = msg.yiaddr;
state_transition(cli, S_REQUESTING);
break;
cli->router = INADDR_ANY;
}
state_transition(cli, S_BOUND);
- VLOG_DBG("Bound: %s", dhcp_msg_to_string(&msg, &cli->s));
+ VLOG_DBG("Bound: %s", dhcp_msg_to_string(&msg, false, &cli->s));
return true;
}
}
{
bool was_bound = dhclient_is_bound(cli);
bool am_bound;
- VLOG_DBG("entering %s", state_name(state));
- cli->state = state;
+ if (cli->state != state) {
+ VLOG_DBG("entering %s", state_name(state));
+ cli->state = state;
+ }
cli->state_entered = time(0);
cli->retransmit = cli->delay = 0;
am_bound = dhclient_is_bound(cli);
if (was_bound != am_bound) {
- struct in_addr addr, mask;
- int error;
-
cli->changed = true;
if (am_bound) {
- VLOG_WARN("%s: binding to "IP_FMT"/"IP_FMT,
+ assert(cli->binding != NULL);
+ VLOG_WARN("%s: obtained address "IP_FMT", netmask "IP_FMT,
netdev_get_name(cli->netdev),
IP_ARGS(&cli->ipaddr), IP_ARGS(&cli->netmask));
- addr.s_addr = cli->ipaddr;
- mask.s_addr = cli->netmask;
- } else {
- VLOG_WARN("%s: unbinding IPv4 network address",
- netdev_get_name(cli->netdev));
- addr.s_addr = mask.s_addr = INADDR_ANY;
- }
- error = netdev_set_in4(cli->netdev, addr, mask);
- if (error) {
- VLOG_ERR("could not set %s address "IP_FMT"/"IP_FMT": %s",
- netdev_get_name(cli->netdev),
- IP_ARGS(&addr.s_addr), IP_ARGS(&mask.s_addr),
- strerror(error));
- }
- if (am_bound && !error && cli->router) {
- struct in_addr router = { cli->router };
- error = netdev_add_router(cli->netdev, router);
- VLOG_WARN("%s: configuring router "IP_FMT,
- netdev_get_name(cli->netdev), IP_ARGS(cli->router));
- if (error) {
- VLOG_ERR("failed to add default route to "IP_FMT" on %s: %s",
- IP_ARGS(&router), netdev_get_name(cli->netdev),
- strerror(error));
+ if (cli->router) {
+ VLOG_WARN("%s: obtained default gateway "IP_FMT,
+ netdev_get_name(cli->netdev), IP_ARGS(&cli->router));
}
- }
- if (am_bound) {
- assert(cli->binding != NULL);
} else {
dhcp_msg_uninit(cli->binding);
free(cli->binding);
cli->binding = NULL;
+
+ VLOG_WARN("%s: network address unbound",
+ netdev_get_name(cli->netdev));
}
}
if (cli->state & (S_SELECTING | S_REQUESTING | S_REBOOTING)) {
msg->secs = cli->secs;
msg->type = type;
memcpy(msg->chaddr, netdev_get_etheraddr(cli->netdev), ETH_ADDR_LEN);
-
}
static unsigned int
buffer_clear(&b);
error = netdev_recv(cli->netdev, &b);
if (error) {
- break;
+ goto drained;
}
flow_extract(&b, 0, &flow);
buffer_pull(&b, b.l7 - b.data);
error = dhcp_parse(msg, &b);
if (!error) {
- VLOG_DBG("received %s", dhcp_msg_to_string(msg, &cli->s));
+ VLOG_DBG("received %s", dhcp_msg_to_string(msg, false, &cli->s));
buffer_uninit(&b);
return true;
}
}
netdev_drain(cli->netdev);
+drained:
buffer_uninit(&b);
return false;
}
* frame to have to be discarded or fragmented if it travels over a regular
* Ethernet at some point. 1500 bytes should be enough for anyone. */
if (b.size <= ETH_TOTAL_MAX) {
- VLOG_DBG("sending %s", dhcp_msg_to_string(msg, &cli->s));
+ VLOG_DBG("sending %s", dhcp_msg_to_string(msg, false, &cli->s));
error = netdev_send(cli->netdev, &b);
if (error) {
VLOG_ERR("send failed on %s: %s",