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authorDenys Vlasenko <vda.linux@googlemail.com>2009-06-26 21:23:16 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2009-06-26 21:23:16 (GMT)
commit4248c33a8528564213d0787770e64b224d134c26 (patch)
treee1e6cc372f5f69917b00a0503f69559c793ee3f4
parentd30b89c7eee19f395af0335b66822989c770437e (diff)
downloadbusybox-4248c33a8528564213d0787770e64b224d134c26.tar.gz
busybox-4248c33a8528564213d0787770e64b224d134c26.tar.bz2
udhcpc: fix a read error loop (e.g.: device is down) blocking TERM
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--networking/udhcp/dhcpc.c299
1 files changed, 151 insertions, 148 deletions
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index fca5c2a..077098f 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -307,7 +307,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
/* Goes to stdout (unless NOMMU) and possibly syslog */
bb_info_msg("%s (v"BB_VER") started", applet_name);
- /* if not set, and not suppressed, setup the default client ID */
+ /* If not set, and not suppressed, set up the default client ID */
if (!client_config.clientid && !(opt & OPT_C)) {
client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
client_config.clientid[OPT_DATA] = 1;
@@ -317,7 +317,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
if (!client_config.vendorclass)
client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, "udhcp "BB_VER, 0);
- /* setup the signal pipe */
+ /* Set up the signal pipe */
udhcp_sp_setup();
state = INIT_SELECTING;
@@ -467,19 +467,45 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
/* yah, I know, *you* say it would never happen */
timeout = INT_MAX;
continue; /* back to main loop */
+ } /* if select timed out */
+
+ /* select() didn't timeout, something happened */
+
+ /* Is it a signal? */
+ /* note: udhcp_sp_read checks FD_ISSET before reading */
+ switch (udhcp_sp_read(&rfds)) {
+ case SIGUSR1:
+ perform_renew();
+ /* Start things over */
+ packet_num = 0;
+ /* Kill any timeouts because the user wants this to hurry along */
+ timeout = 0;
+ continue;
+ case SIGUSR2:
+ perform_release(requested_ip, server_addr);
+ timeout = INT_MAX;
+ continue;
+ case SIGTERM:
+ bb_info_msg("Received SIGTERM");
+ if (opt & OPT_R) /* release on quit */
+ perform_release(requested_ip, server_addr);
+ goto ret0;
}
- /* select() didn't timeout, something did happen. */
/* Is it a packet? */
- if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
+ if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
+ continue; /* no */
+
+ {
int len;
- /* A packet is ready, read it */
+ /* A packet is ready, read it */
if (listen_mode == LISTEN_KERNEL)
len = udhcp_recv_kernel_packet(&packet, sockfd);
else
len = udhcp_recv_raw_packet(&packet, sockfd);
- if (len == -1) { /* error is severe, reopen socket */
+ if (len == -1) {
+ /* Error is severe, reopen socket */
bb_info_msg("Read error: %s, reopening socket", strerror(errno));
sleep(discover_timeout); /* 3 seconds by default */
change_listen_mode(listen_mode); /* just close and reopen */
@@ -490,70 +516,71 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
if (len < 0)
continue;
+ }
- if (packet.xid != xid) {
- log1("xid %x (our is %x), ignoring packet",
- (unsigned)packet.xid, (unsigned)xid);
- continue;
- }
+ if (packet.xid != xid) {
+ log1("xid %x (our is %x), ignoring packet",
+ (unsigned)packet.xid, (unsigned)xid);
+ continue;
+ }
- /* Ignore packets that aren't for us */
- if (packet.hlen != 6
- || memcmp(packet.chaddr, client_config.client_mac, 6)
- ) {
+ /* Ignore packets that aren't for us */
+ if (packet.hlen != 6
+ || memcmp(packet.chaddr, client_config.client_mac, 6)
+ ) {
//FIXME: need to also check that last 10 bytes are zero
- log1("chaddr does not match, ignoring packet"); // log2?
- continue;
- }
+ log1("chaddr does not match, ignoring packet"); // log2?
+ continue;
+ }
- message = get_option(&packet, DHCP_MESSAGE_TYPE);
- if (message == NULL) {
- bb_error_msg("no message type option, ignoring packet");
- continue;
- }
+ message = get_option(&packet, DHCP_MESSAGE_TYPE);
+ if (message == NULL) {
+ bb_error_msg("no message type option, ignoring packet");
+ continue;
+ }
- switch (state) {
- case INIT_SELECTING:
- /* Must be a DHCPOFFER to one of our xid's */
- if (*message == DHCPOFFER) {
- /* TODO: why we don't just fetch server's IP from IP header? */
- temp = get_option(&packet, DHCP_SERVER_ID);
- if (!temp) {
- bb_error_msg("no server ID in message");
- continue;
- /* still selecting - this server looks bad */
- }
+ switch (state) {
+ case INIT_SELECTING:
+ /* Must be a DHCPOFFER to one of our xid's */
+ if (*message == DHCPOFFER) {
+ /* TODO: why we don't just fetch server's IP from IP header? */
+ temp = get_option(&packet, DHCP_SERVER_ID);
+ if (!temp) {
+ bb_error_msg("no server ID in message");
+ continue;
+ /* still selecting - this server looks bad */
+ }
+ /* it IS unaligned sometimes, don't "optimize" */
+ move_from_unaligned32(server_addr, temp);
+ xid = packet.xid;
+ requested_ip = packet.yiaddr;
+
+ /* enter requesting state */
+ state = REQUESTING;
+ timeout = 0;
+ packet_num = 0;
+ already_waited_sec = 0;
+ }
+ continue;
+ case RENEW_REQUESTED:
+ case REQUESTING:
+ case RENEWING:
+ case REBINDING:
+ if (*message == DHCPACK) {
+ temp = get_option(&packet, DHCP_LEASE_TIME);
+ if (!temp) {
+ bb_error_msg("no lease time with ACK, using 1 hour lease");
+ lease_seconds = 60 * 60;
+ } else {
/* it IS unaligned sometimes, don't "optimize" */
- move_from_unaligned32(server_addr, temp);
- xid = packet.xid;
- requested_ip = packet.yiaddr;
-
- /* enter requesting state */
- state = REQUESTING;
- timeout = 0;
- packet_num = 0;
- already_waited_sec = 0;
+ move_from_unaligned32(lease_seconds, temp);
+ lease_seconds = ntohl(lease_seconds);
+ lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
+ if (lease_seconds < 10) /* and not too small */
+ lease_seconds = 10;
}
- continue;
- case RENEW_REQUESTED:
- case REQUESTING:
- case RENEWING:
- case REBINDING:
- if (*message == DHCPACK) {
- temp = get_option(&packet, DHCP_LEASE_TIME);
- if (!temp) {
- bb_error_msg("no lease time with ACK, using 1 hour lease");
- lease_seconds = 60 * 60;
- } else {
- /* it IS unaligned sometimes, don't "optimize" */
- move_from_unaligned32(lease_seconds, temp);
- lease_seconds = ntohl(lease_seconds);
- lease_seconds &= 0x0fffffff; /* paranoia: must not be prone to overflows */
- if (lease_seconds < 10) /* and not too small */
- lease_seconds = 10;
- }
#if ENABLE_FEATURE_UDHCPC_ARPING
- if (opt & OPT_a) {
+ if (opt & OPT_a) {
/* RFC 2131 3.1 paragraph 5:
* "The client receives the DHCPACK message with configuration
* parameters. The client SHOULD perform a final check on the
@@ -563,100 +590,76 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
* address is already in use (e.g., through the use of ARP),
* the client MUST send a DHCPDECLINE message to the server and restarts
* the configuration process..." */
- if (!arpping(packet.yiaddr,
- NULL,
- (uint32_t) 0,
- client_config.client_mac,
- client_config.interface)
- ) {
- bb_info_msg("Offered address is in use "
- "(got ARP reply), declining");
- send_decline(xid, server_addr, packet.yiaddr);
-
- if (state != REQUESTING)
- udhcp_run_script(NULL, "deconfig");
- change_listen_mode(LISTEN_RAW);
- state = INIT_SELECTING;
- requested_ip = 0;
- timeout = tryagain_timeout;
- packet_num = 0;
- already_waited_sec = 0;
- continue; /* back to main loop */
- }
- }
-#endif
- /* enter bound state */
- timeout = lease_seconds / 2;
- {
- struct in_addr temp_addr;
- temp_addr.s_addr = packet.yiaddr;
- bb_info_msg("Lease of %s obtained, lease time %u",
- inet_ntoa(temp_addr), (unsigned)lease_seconds);
- }
- requested_ip = packet.yiaddr;
- udhcp_run_script(&packet,
- ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
-
- state = BOUND;
- change_listen_mode(LISTEN_NONE);
- if (opt & OPT_q) { /* quit after lease */
- if (opt & OPT_R) /* release on quit */
- perform_release(requested_ip, server_addr);
- goto ret0;
- }
-#if BB_MMU /* NOMMU case backgrounded earlier */
- if (!(opt & OPT_f)) {
- client_background();
- /* do not background again! */
- opt = ((opt & ~OPT_b) | OPT_f);
+ if (!arpping(packet.yiaddr,
+ NULL,
+ (uint32_t) 0,
+ client_config.client_mac,
+ client_config.interface)
+ ) {
+ bb_info_msg("Offered address is in use "
+ "(got ARP reply), declining");
+ send_decline(xid, server_addr, packet.yiaddr);
+
+ if (state != REQUESTING)
+ udhcp_run_script(NULL, "deconfig");
+ change_listen_mode(LISTEN_RAW);
+ state = INIT_SELECTING;
+ requested_ip = 0;
+ timeout = tryagain_timeout;
+ packet_num = 0;
+ already_waited_sec = 0;
+ continue; /* back to main loop */
}
+ }
#endif
- already_waited_sec = 0;
- continue; /* back to main loop */
+ /* enter bound state */
+ timeout = lease_seconds / 2;
+ {
+ struct in_addr temp_addr;
+ temp_addr.s_addr = packet.yiaddr;
+ bb_info_msg("Lease of %s obtained, lease time %u",
+ inet_ntoa(temp_addr), (unsigned)lease_seconds);
}
- if (*message == DHCPNAK) {
- /* return to init state */
- bb_info_msg("Received DHCP NAK");
- udhcp_run_script(&packet, "nak");
- if (state != REQUESTING)
- udhcp_run_script(NULL, "deconfig");
- change_listen_mode(LISTEN_RAW);
- sleep(3); /* avoid excessive network traffic */
- state = INIT_SELECTING;
- requested_ip = 0;
- timeout = 0;
- packet_num = 0;
- already_waited_sec = 0;
+ requested_ip = packet.yiaddr;
+ udhcp_run_script(&packet,
+ ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));
+
+ state = BOUND;
+ change_listen_mode(LISTEN_NONE);
+ if (opt & OPT_q) { /* quit after lease */
+ if (opt & OPT_R) /* release on quit */
+ perform_release(requested_ip, server_addr);
+ goto ret0;
}
- continue;
- /* case BOUND, RELEASED: - ignore all packets */
+#if BB_MMU /* NOMMU case backgrounded earlier */
+ if (!(opt & OPT_f)) {
+ client_background();
+ /* do not background again! */
+ opt = ((opt & ~OPT_b) | OPT_f);
+ }
+#endif
+ already_waited_sec = 0;
+ continue; /* back to main loop */
}
- continue; /* back to main loop */
- }
-
- /* select() didn't timeout, something did happen.
- * But it wasn't a packet. It's a signal pipe then. */
- {
- int signo = udhcp_sp_read(&rfds);
- switch (signo) {
- case SIGUSR1:
- perform_renew();
- /* start things over */
- packet_num = 0;
- /* Kill any timeouts because the user wants this to hurry along */
+ if (*message == DHCPNAK) {
+ /* return to init state */
+ bb_info_msg("Received DHCP NAK");
+ udhcp_run_script(&packet, "nak");
+ if (state != REQUESTING)
+ udhcp_run_script(NULL, "deconfig");
+ change_listen_mode(LISTEN_RAW);
+ sleep(3); /* avoid excessive network traffic */
+ state = INIT_SELECTING;
+ requested_ip = 0;
timeout = 0;
- break;
- case SIGUSR2:
- perform_release(requested_ip, server_addr);
- timeout = INT_MAX;
- break;
- case SIGTERM:
- bb_info_msg("Received SIGTERM");
- if (opt & OPT_R) /* release on quit */
- perform_release(requested_ip, server_addr);
- goto ret0;
+ packet_num = 0;
+ already_waited_sec = 0;
}
+ continue;
+ /* case BOUND: - ignore all packets */
+ /* case RELEASED: - ignore all packets */
}
+ /* back to main loop */
} /* for (;;) - main loop ends */
ret0: