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udhcpc: fix a read error loop (e.g.: device is down) blocking TERM

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Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2009-06-26 23:23:16 +02:00
parent d30b89c7ee
commit 4248c33a85
1 changed files with 151 additions and 148 deletions
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299
networking/udhcp/dhcpc.c
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@ -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)) {
int len;
/* A packet is ready, read it */
if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
continue; /* no */
{
int len;
/* 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 */
}
/* 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;
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(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 (!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 */
}
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"));
/* 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;
}
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 (!(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 */
}
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;
}
continue;
/* case BOUND, RELEASED: - ignore all packets */
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: