/* vi: set sw=4 ts=4: */
/*
* udhcp client
- *
* Russ Dill <Russ.Dill@asu.edu> July 2001
*
* This program is free software; you can redistribute it and/or modify
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+//applet:IF_UDHCPC(APPLET(udhcpc, BB_DIR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_UDHCPC) += common.o packet.o signalpipe.o socket.o
+//kbuild:lib-$(CONFIG_UDHCPC) += dhcpc.o
+//kbuild:lib-$(CONFIG_FEATURE_UDHCPC_ARPING) += arpping.o
+//kbuild:lib-$(CONFIG_FEATURE_UDHCP_RFC3397) += domain_codec.o
+
#include <syslog.h>
/* Override ENABLE_FEATURE_PIDFILE - ifupdown needs our pidfile to always exist */
#define WANT_PIDFILE 1
#include <linux/filter.h>
#include <linux/if_packet.h>
-/* "struct client_config_t client_config" is in bb_common_bufsiz1 */
+#ifndef PACKET_AUXDATA
+# define PACKET_AUXDATA 8
+struct tpacket_auxdata {
+ uint32_t tp_status;
+ uint32_t tp_len;
+ uint32_t tp_snaplen;
+ uint16_t tp_mac;
+ uint16_t tp_net;
+ uint16_t tp_vlan_tci;
+ uint16_t tp_padding;
+};
+#endif
+
+
+/* "struct client_data_t client_data" is in bb_common_bufsiz1 */
#if ENABLE_LONG_OPTS
"request-option\0" Required_argument "O"
"no-default-options\0" No_argument "o"
"foreground\0" No_argument "f"
+ USE_FOR_MMU(
"background\0" No_argument "b"
+ )
"broadcast\0" No_argument "B"
- IF_FEATURE_UDHCPC_ARPING("arping\0" No_argument "a")
+ IF_FEATURE_UDHCPC_ARPING("arping\0" Optional_argument "a")
IF_FEATURE_UDHCP_PORT("client-port\0" Required_argument "P")
;
#endif
/*** Script execution code ***/
/* get a rough idea of how long an option will be (rounding up...) */
-static const uint8_t len_of_option_as_string[] = {
+static const uint8_t len_of_option_as_string[] ALIGN1 = {
[OPTION_IP ] = sizeof("255.255.255.255 "),
[OPTION_IP_PAIR ] = sizeof("255.255.255.255 ") * 2,
[OPTION_STATIC_ROUTES ] = sizeof("255.255.255.255/32 255.255.255.255 "),
- [OPTION_6RD ] = sizeof("32 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "),
+ [OPTION_6RD ] = sizeof("132 128 ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff 255.255.255.255 "),
[OPTION_STRING ] = 1,
[OPTION_STRING_HOST ] = 1,
#if ENABLE_FEATURE_UDHCP_RFC3397
return i;
}
-/* Check if a given label represents a valid DNS label
- * Return pointer to the first character after the label upon success,
- * NULL otherwise.
- * See RFC1035, 2.3.1
- */
+#if ENABLE_FEATURE_UDHCPC_SANITIZEOPT
+/* Check if a given name represents a valid DNS name */
+/* See RFC1035, 2.3.1 */
/* We don't need to be particularly anal. For example, allowing _, hyphen
* at the end, or leading and trailing dots would be ok, since it
- * can't be used for attacks. (Leading hyphen can be, if someone uses
- * cmd "$hostname"
+ * can't be used for attacks. (Leading hyphen can be, if someone uses cmd "$hostname"
* in the script: then hostname may be treated as an option)
*/
-static const char *valid_domain_label(const char *label)
-{
- unsigned char ch;
- unsigned pos = 0;
-
- for (;;) {
- ch = *label;
- if ((ch|0x20) < 'a' || (ch|0x20) > 'z') {
- if (pos == 0) {
- /* label must begin with letter */
- return NULL;
- }
- if (ch < '0' || ch > '9') {
- if (ch == '\0' || ch == '.')
- return label;
- /* DNS allows only '-', but we are more permissive */
- if (ch != '-' && ch != '_')
- return NULL;
- }
- }
- label++;
- pos++;
- //Do we want this?
- //if (pos > 63) /* NS_MAXLABEL; labels must be 63 chars or less */
- // return NULL;
- }
-}
-
-/* Check if a given name represents a valid DNS name */
-/* See RFC1035, 2.3.1 */
static int good_hostname(const char *name)
{
- //const char *start = name;
-
- for (;;) {
- name = valid_domain_label(name);
- if (!name)
- return 0;
- if (!name[0])
- return 1;
- //Do we want this?
- //return ((name - start) < 1025); /* NS_MAXDNAME */
- name++;
+ if (*name == '-') /* Can't start with '-' */
+ return 0;
+
+ while (*name) {
+ unsigned char ch = *name++;
+ if (!isalnum(ch))
+ /* DNS allows only '-', but we are more permissive */
+ if (ch != '-' && ch != '_' && ch != '.')
+ return 0;
+ // TODO: do we want to validate lengths against NS_MAXLABEL and NS_MAXDNAME?
}
+ return 1;
}
+#else
+# define good_hostname(name) 1
+#endif
/* Create "opt_name=opt_value" string */
static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
type = optflag->flags & OPTION_TYPE_MASK;
optlen = dhcp_option_lengths[type];
upper_length = len_of_option_as_string[type]
- * ((unsigned)(len + optlen - 1) / (unsigned)optlen);
+ * ((unsigned)(len + optlen) / (unsigned)optlen);
dest = ret = xmalloc(upper_length + strlen(opt_name) + 2);
dest += sprintf(ret, "%s=", opt_name);
case OPTION_IP:
case OPTION_IP_PAIR:
dest += sprint_nip(dest, "", option);
- if (type == OPTION_IP)
- break;
- dest += sprint_nip(dest, "/", option + 4);
+ if (type == OPTION_IP_PAIR)
+ dest += sprint_nip(dest, "/", option + 4);
break;
// case OPTION_BOOLEAN:
// dest += sprintf(dest, *option ? "yes" : "no");
case OPTION_STRING_HOST:
memcpy(dest, option, len);
dest[len] = '\0';
+//TODO: it appears option 15 DHCP_DOMAIN_NAME is often abused
+//by DHCP admins to contain a space-separated list of domains,
+//not one domain name (presumably, to work as list of search domains,
+//instead of using proper option 119 DHCP_DOMAIN_SEARCH).
+//Currently, good_hostname() balks on strings containing spaces.
+//Do we need to allow it? Only for DHCP_DOMAIN_NAME option?
if (type == OPTION_STRING_HOST && !good_hostname(dest))
safe_strncpy(dest, "bad", len);
return ret;
* IPv4MaskLen <= 32,
* 6rdPrefixLen <= 128,
* 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
- * (2nd condition need no check - it follows from 1st and 3rd).
+ * (2nd condition needs no check - it follows from 1st and 3rd).
* Else, return envvar with empty value ("optname=")
*/
if (len >= (1 + 1 + 16 + 4)
/* 6rdPrefix */
dest += sprint_nip6(dest, /* "", */ option);
option += 16;
- len -= 1 + 1 + 16 + 4;
- /* "+ 4" above corresponds to the length of IPv4 addr
- * we consume in the loop below */
- while (1) {
- /* 6rdBRIPv4Address(es) */
- dest += sprint_nip(dest, " ", option);
- option += 4;
- len -= 4; /* do we have yet another 4+ bytes? */
- if (len < 0)
- break; /* no */
- }
+ len -= 1 + 1 + 16;
+ *dest++ = ' ';
+ /* 6rdBRIPv4Address(es), use common IPv4 logic to process them */
+ type = OPTION_IP;
+ optlen = 4;
+ continue;
}
return ret;
*/
option++;
len--;
+ if (option[-1] == 1) {
+ /* use common IPv4 logic to process IP addrs */
+ type = OPTION_IP;
+ optlen = 4;
+ continue;
+ }
if (option[-1] == 0) {
dest = dname_dec(option, len, ret);
if (dest) {
free(ret);
return dest;
}
- } else
- if (option[-1] == 1) {
- const char *pfx = "";
- while (1) {
- len -= 4;
- if (len < 0)
- break;
- dest += sprint_nip(dest, pfx, option);
- pfx = " ";
- option += 4;
- }
}
return ret;
#endif
memset(found_opts, 0, sizeof(found_opts));
- /* We need 6 elements for:
+ /* We need 7 elements for:
* "interface=IFACE"
* "ip=N.N.N.N" from packet->yiaddr
+ * "giaddr=IP" from packet->gateway_nip (unless 0)
* "siaddr=IP" from packet->siaddr_nip (unless 0)
* "boot_file=FILE" from packet->file (unless overloaded)
* "sname=SERVER_HOSTNAME" from packet->sname (unless overloaded)
* terminating NULL
*/
- envc = 6;
+ envc = 7;
/* +1 element for each option, +2 for subnet option: */
if (packet) {
/* note: do not search for "pad" (0) and "end" (255) options */
temp = udhcp_get_option(packet, i);
if (temp) {
if (i == DHCP_OPTION_OVERLOAD)
- overload = *temp;
+ overload |= *temp;
else if (i == DHCP_SUBNET)
envc++; /* for $mask */
envc++;
}
curr = envp = xzalloc(sizeof(envp[0]) * envc);
- *curr = xasprintf("interface=%s", client_config.interface);
+ *curr = xasprintf("interface=%s", client_data.interface);
putenv(*curr++);
if (!packet)
* uint16_t secs; // elapsed since client began acquisition/renewal
* uint16_t flags; // only one flag so far: bcast. Never set by server
* uint32_t ciaddr; // client IP (usually == yiaddr. can it be different
- * // if during renew server wants to give us differn IP?)
- * uint32_t gateway_nip; // relay agent IP address
+ * // if during renew server wants to give us different IP?)
* uint8_t chaddr[16]; // link-layer client hardware address (MAC)
- * TODO: export gateway_nip as $giaddr?
*/
/* Most important one: yiaddr as $ip */
*curr = xmalloc(sizeof("ip=255.255.255.255"));
sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
putenv(*curr++);
}
+ if (packet->gateway_nip) {
+ /* IP address of DHCP relay agent */
+ *curr = xmalloc(sizeof("giaddr=255.255.255.255"));
+ sprint_nip(*curr, "giaddr=", (uint8_t *) &packet->gateway_nip);
+ putenv(*curr++);
+ }
if (!(overload & FILE_FIELD) && packet->file[0]) {
/* watch out for invalid packets */
*curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
temp = udhcp_get_option(packet, code);
*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
putenv(*curr++);
- if (code == DHCP_SUBNET) {
+ if (code == DHCP_SUBNET && temp[-OPT_DATA + OPT_LEN] == 4) {
/* Subnet option: make things like "$ip/$mask" possible */
uint32_t subnet;
move_from_unaligned32(subnet, temp);
envp = fill_envp(packet);
/* call script */
- log1("Executing %s %s", client_config.script, name);
- argv[0] = (char*) client_config.script;
+ log1("executing %s %s", client_data.script, name);
+ argv[0] = (char*) client_data.script;
argv[1] = (char*) name;
argv[2] = NULL;
spawn_and_wait(argv);
/* Initialize the packet with the proper defaults */
static void init_packet(struct dhcp_packet *packet, char type)
{
- uint16_t secs;
+ unsigned secs;
/* Fill in: op, htype, hlen, cookie fields; message type option: */
udhcp_init_header(packet, type);
packet->xid = random_xid();
- client_config.last_secs = monotonic_sec();
- if (client_config.first_secs == 0)
- client_config.first_secs = client_config.last_secs;
- secs = client_config.last_secs - client_config.first_secs;
- packet->secs = htons(secs);
+ client_data.last_secs = monotonic_sec();
+ if (client_data.first_secs == 0)
+ client_data.first_secs = client_data.last_secs;
+ secs = client_data.last_secs - client_data.first_secs;
+ packet->secs = (secs < 0xffff) ? htons(secs) : 0xffff;
- memcpy(packet->chaddr, client_config.client_mac, 6);
- if (client_config.clientid)
- udhcp_add_binary_option(packet, client_config.clientid);
+ memcpy(packet->chaddr, client_data.client_mac, 6);
+ if (client_data.clientid)
+ udhcp_add_binary_option(packet, client_data.clientid);
}
static void add_client_options(struct dhcp_packet *packet)
end = udhcp_end_option(packet->options);
len = 0;
for (i = 1; i < DHCP_END; i++) {
- if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
+ if (client_data.opt_mask[i >> 3] & (1 << (i & 7))) {
packet->options[end + OPT_DATA + len] = i;
len++;
}
packet->options[end + OPT_DATA + len] = DHCP_END;
}
- if (client_config.vendorclass)
- udhcp_add_binary_option(packet, client_config.vendorclass);
- if (client_config.hostname)
- udhcp_add_binary_option(packet, client_config.hostname);
- if (client_config.fqdn)
- udhcp_add_binary_option(packet, client_config.fqdn);
+ if (client_data.vendorclass)
+ udhcp_add_binary_option(packet, client_data.vendorclass);
+ if (client_data.hostname)
+ udhcp_add_binary_option(packet, client_data.hostname);
+ if (client_data.fqdn)
+ udhcp_add_binary_option(packet, client_data.fqdn);
/* Request broadcast replies if we have no IP addr */
if ((option_mask32 & OPT_B) && packet->ciaddr == 0)
/* Add -x options if any */
{
- struct option_set *curr = client_config.options;
+ struct option_set *curr = client_data.options;
while (curr) {
udhcp_add_binary_option(packet, curr->data);
curr = curr->next;
}
-// if (client_config.sname)
-// strncpy((char*)packet->sname, client_config.sname, sizeof(packet->sname) - 1);
-// if (client_config.boot_file)
-// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
+// if (client_data.sname)
+// strncpy((char*)packet->sname, client_data.sname, sizeof(packet->sname) - 1);
+// if (client_data.boot_file)
+// strncpy((char*)packet->file, client_data.boot_file, sizeof(packet->file) - 1);
}
// This will be needed if we remove -V VENDOR_STR in favor of
* client reverts to using the IP broadcast address.
*/
-static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
+static int raw_bcast_from_client_data_ifindex(struct dhcp_packet *packet, uint32_t src_nip)
{
return udhcp_send_raw_packet(packet,
- /*src*/ INADDR_ANY, CLIENT_PORT,
+ /*src*/ src_nip, CLIENT_PORT,
/*dst*/ INADDR_BROADCAST, SERVER_PORT, MAC_BCAST_ADDR,
- client_config.ifindex);
+ client_data.ifindex);
+}
+
+static int bcast_or_ucast(struct dhcp_packet *packet, uint32_t ciaddr, uint32_t server)
+{
+ if (server)
+ return udhcp_send_kernel_packet(packet,
+ ciaddr, CLIENT_PORT,
+ server, SERVER_PORT);
+ return raw_bcast_from_client_data_ifindex(packet, ciaddr);
}
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
*/
add_client_options(&packet);
- bb_info_msg("Sending discover...");
- return raw_bcast_from_client_config_ifindex(&packet);
+ bb_info_msg("sending %s", "discover");
+ return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY);
}
/* Broadcast a DHCP request message */
static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
- struct in_addr addr;
+ struct in_addr temp_addr;
/*
* RFC 2131 4.3.2 DHCPREQUEST message
*/
add_client_options(&packet);
- addr.s_addr = requested;
- bb_info_msg("Sending select for %s...", inet_ntoa(addr));
- return raw_bcast_from_client_config_ifindex(&packet);
+ temp_addr.s_addr = requested;
+ bb_info_msg("sending select for %s", inet_ntoa(temp_addr));
+ return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY);
}
/* Unicast or broadcast a DHCP renew message */
static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
+ struct in_addr temp_addr;
/*
* RFC 2131 4.3.2 DHCPREQUEST message
*/
add_client_options(&packet);
- bb_info_msg("Sending renew...");
- if (server)
- return udhcp_send_kernel_packet(&packet,
- ciaddr, CLIENT_PORT,
- server, SERVER_PORT);
- return raw_bcast_from_client_config_ifindex(&packet);
+ temp_addr.s_addr = server;
+ bb_info_msg("sending renew to %s", inet_ntoa(temp_addr));
+ return bcast_or_ucast(&packet, ciaddr, server);
}
#if ENABLE_FEATURE_UDHCPC_ARPING
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
- bb_info_msg("Sending decline...");
- return raw_bcast_from_client_config_ifindex(&packet);
+ bb_info_msg("sending %s", "decline");
+ return raw_bcast_from_client_data_ifindex(&packet, INADDR_ANY);
}
#endif
/* Unicast a DHCP release message */
-static int send_release(uint32_t server, uint32_t ciaddr)
+static
+ALWAYS_INLINE /* one caller, help compiler to use this fact */
+int send_release(uint32_t server, uint32_t ciaddr)
{
struct dhcp_packet packet;
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
- bb_info_msg("Sending release...");
- return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ bb_info_msg("sending %s", "release");
+ /* Note: normally we unicast here since "server" is not zero.
+ * However, there _are_ people who run "address-less" DHCP servers,
+ * and reportedly ISC dhcp client and Windows allow that.
+ */
+ return bcast_or_ucast(&packet, ciaddr, server);
}
/* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
if (bytes < 0) {
if (errno == EINTR)
continue;
- log1("Packet read error, ignoring");
+ log1s("packet read error, ignoring");
/* NB: possible down interface, etc. Caller should pause. */
return bytes; /* returns -1 */
}
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
- log1("Packet is too short, ignoring");
+ log1s("packet is too short, ignoring");
return -2;
}
if (bytes < ntohs(packet.ip.tot_len)) {
/* packet is bigger than sizeof(packet), we did partial read */
- log1("Oversized packet, ignoring");
+ log1s("oversized packet, ignoring");
return -2;
}
/* || bytes > (int) sizeof(packet) - can't happen */
|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
) {
- log1("Unrelated/bogus packet, ignoring");
+ log1s("unrelated/bogus packet, ignoring");
return -2;
}
check = packet.ip.check;
packet.ip.check = 0;
if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) {
- log1("Bad IP header checksum, ignoring");
+ log1s("bad IP header checksum, ignoring");
return -2;
}
check = packet.udp.check;
packet.udp.check = 0;
if (check && check != inet_cksum((uint16_t *)&packet, bytes)) {
- log1("Packet with bad UDP checksum received, ignoring");
+ log1s("packet with bad UDP checksum received, ignoring");
return -2;
}
skip_udp_sum_check:
if (packet.data.cookie != htonl(DHCP_MAGIC)) {
- bb_info_msg("Packet with bad magic, ignoring");
+ bb_simple_info_msg("packet with bad magic, ignoring");
return -2;
}
- log1("Received a packet");
+ log1("received %s", "a packet");
udhcp_dump_packet(&packet.data);
bytes -= sizeof(packet.ip) + sizeof(packet.udp);
/*** Main ***/
-static int sockfd = -1;
-
+/* Values for client_data.listen_mode */
#define LISTEN_NONE 0
#define LISTEN_KERNEL 1
#define LISTEN_RAW 2
-static smallint listen_mode;
+/* Values for client_data.state */
/* initial state: (re)start DHCP negotiation */
#define INIT_SELECTING 0
/* discover was sent, DHCPOFFER reply received */
#define RENEW_REQUESTED 5
/* release, possibly manually requested (SIGUSR2) */
#define RELEASED 6
-static smallint state;
static int udhcp_raw_socket(int ifindex)
{
int fd;
struct sockaddr_ll sock;
- /*
- * Comment:
- *
- * I've selected not to see LL header, so BPF doesn't see it, too.
- * The filter may also pass non-IP and non-ARP packets, but we do
- * a more complete check when receiving the message in userspace.
- *
- * and filter shamelessly stolen from:
- *
- * http://www.flamewarmaster.de/software/dhcpclient/
- *
- * There are a few other interesting ideas on that page (look under
- * "Motivation"). Use of netlink events is most interesting. Think
- * of various network servers listening for events and reconfiguring.
- * That would obsolete sending HUP signals and/or make use of restarts.
- *
- * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
- * License: GPL v2.
- *
- * TODO: make conditional?
- */
- static const struct sock_filter filter_instr[] = {
- /* load 9th byte (protocol) */
- BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
- /* jump to L1 if it is IPPROTO_UDP, else to L4 */
- BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
- /* L1: load halfword from offset 6 (flags and frag offset) */
- BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
- /* jump to L4 if any bits in frag offset field are set, else to L2 */
- BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
- /* L2: skip IP header (load index reg with header len) */
- BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
- /* load udp destination port from halfword[header_len + 2] */
- BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
- /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
- BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
- /* L3: accept packet */
- BPF_STMT(BPF_RET|BPF_K, 0xffffffff),
- /* L4: discard packet */
- BPF_STMT(BPF_RET|BPF_K, 0),
- };
- static const struct sock_fprog filter_prog = {
- .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
- /* casting const away: */
- .filter = (struct sock_filter *) filter_instr,
- };
-
- log1("Opening raw socket on ifindex %d", ifindex); //log2?
+ log2("opening raw socket on ifindex %d", ifindex);
fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
- log1("Got raw socket fd"); //log2?
+ /* ^^^^^
+ * SOCK_DGRAM: remove link-layer headers on input (SOCK_RAW keeps them)
+ * ETH_P_IP: want to receive only packets with IPv4 eth type
+ */
+ log3("got raw socket fd %d", fd);
+ memset(&sock, 0, sizeof(sock)); /* let's be deterministic */
sock.sll_family = AF_PACKET;
sock.sll_protocol = htons(ETH_P_IP);
sock.sll_ifindex = ifindex;
+ /*sock.sll_hatype = ARPHRD_???;*/
+ /*sock.sll_pkttype = PACKET_???;*/
+ /*sock.sll_halen = ???;*/
+ /*sock.sll_addr[8] = ???;*/
xbind(fd, (struct sockaddr *) &sock, sizeof(sock));
+#if 0 /* Several users reported breakage when BPF filter is used */
if (CLIENT_PORT == 68) {
/* Use only if standard port is in use */
+ /*
+ * I've selected not to see LL header, so BPF doesn't see it, too.
+ * The filter may also pass non-IP and non-ARP packets, but we do
+ * a more complete check when receiving the message in userspace.
+ *
+ * and filter shamelessly stolen from:
+ *
+ * http://www.flamewarmaster.de/software/dhcpclient/
+ *
+ * There are a few other interesting ideas on that page (look under
+ * "Motivation"). Use of netlink events is most interesting. Think
+ * of various network servers listening for events and reconfiguring.
+ * That would obsolete sending HUP signals and/or make use of restarts.
+ *
+ * Copyright: 2006, 2007 Stefan Rompf <sux@loplof.de>.
+ * License: GPL v2.
+ */
+ static const struct sock_filter filter_instr[] = {
+ /* load 9th byte (protocol) */
+ BPF_STMT(BPF_LD|BPF_B|BPF_ABS, 9),
+ /* jump to L1 if it is IPPROTO_UDP, else to L4 */
+ BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, IPPROTO_UDP, 0, 6),
+ /* L1: load halfword from offset 6 (flags and frag offset) */
+ BPF_STMT(BPF_LD|BPF_H|BPF_ABS, 6),
+ /* jump to L4 if any bits in frag offset field are set, else to L2 */
+ BPF_JUMP(BPF_JMP|BPF_JSET|BPF_K, 0x1fff, 4, 0),
+ /* L2: skip IP header (load index reg with header len) */
+ BPF_STMT(BPF_LDX|BPF_B|BPF_MSH, 0),
+ /* load udp destination port from halfword[header_len + 2] */
+ BPF_STMT(BPF_LD|BPF_H|BPF_IND, 2),
+ /* jump to L3 if udp dport is CLIENT_PORT, else to L4 */
+ BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, 68, 0, 1),
+ /* L3: accept packet ("accept 0x7fffffff bytes") */
+ /* Accepting 0xffffffff works too but kernel 2.6.19 is buggy */
+ BPF_STMT(BPF_RET|BPF_K, 0x7fffffff),
+ /* L4: discard packet ("accept zero bytes") */
+ BPF_STMT(BPF_RET|BPF_K, 0),
+ };
+ static const struct sock_fprog filter_prog = {
+ .len = sizeof(filter_instr) / sizeof(filter_instr[0]),
+ /* casting const away: */
+ .filter = (struct sock_filter *) filter_instr,
+ };
/* Ignoring error (kernel may lack support for this) */
if (setsockopt(fd, SOL_SOCKET, SO_ATTACH_FILTER, &filter_prog,
sizeof(filter_prog)) >= 0)
- log1("Attached filter to raw socket fd"); // log?
+ log1("attached filter to raw socket fd"); // log?
}
+#endif
- if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA,
- &const_int_1, sizeof(int)) < 0
- ) {
+ if (setsockopt_1(fd, SOL_PACKET, PACKET_AUXDATA) != 0) {
if (errno != ENOPROTOOPT)
- log1("Can't set PACKET_AUXDATA on raw socket");
+ log1s("can't set PACKET_AUXDATA on raw socket");
}
- log1("Created raw socket");
+ log1s("created raw socket");
return fd;
}
static void change_listen_mode(int new_mode)
{
- log1("Entering listen mode: %s",
+ log1("entering listen mode: %s",
new_mode != LISTEN_NONE
? (new_mode == LISTEN_KERNEL ? "kernel" : "raw")
: "none"
);
- listen_mode = new_mode;
- if (sockfd >= 0) {
- close(sockfd);
- sockfd = -1;
+ client_data.listen_mode = new_mode;
+ if (client_data.sockfd >= 0) {
+ close(client_data.sockfd);
+ client_data.sockfd = -1;
}
if (new_mode == LISTEN_KERNEL)
- sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_config.interface);
+ client_data.sockfd = udhcp_listen_socket(/*INADDR_ANY,*/ CLIENT_PORT, client_data.interface);
else if (new_mode != LISTEN_NONE)
- sockfd = udhcp_raw_socket(client_config.ifindex);
- /* else LISTEN_NONE: sockfd stays closed */
+ client_data.sockfd = udhcp_raw_socket(client_data.ifindex);
+ /* else LISTEN_NONE: client_data.sockfd stays closed */
}
/* Called only on SIGUSR1 */
static void perform_renew(void)
{
- bb_info_msg("Performing a DHCP renew");
- switch (state) {
+ bb_simple_info_msg("performing DHCP renew");
+ switch (client_data.state) {
case BOUND:
change_listen_mode(LISTEN_KERNEL);
case RENEWING:
case REBINDING:
- state = RENEW_REQUESTED;
+ client_data.state = RENEW_REQUESTED;
break;
case RENEW_REQUESTED: /* impatient are we? fine, square 1 */
udhcp_run_script(NULL, "deconfig");
case REQUESTING:
case RELEASED:
change_listen_mode(LISTEN_RAW);
- state = INIT_SELECTING;
+ client_data.state = INIT_SELECTING;
break;
case INIT_SELECTING:
break;
struct in_addr temp_addr;
/* send release packet */
- if (state == BOUND || state == RENEWING || state == REBINDING) {
+ if (client_data.state == BOUND
+ || client_data.state == RENEWING
+ || client_data.state == REBINDING
+ || client_data.state == RENEW_REQUESTED
+ ) {
temp_addr.s_addr = server_addr;
strcpy(buffer, inet_ntoa(temp_addr));
temp_addr.s_addr = requested_ip;
- bb_info_msg("Unicasting a release of %s to %s",
+ bb_info_msg("unicasting a release of %s to %s",
inet_ntoa(temp_addr), buffer);
send_release(server_addr, requested_ip); /* unicast */
- udhcp_run_script(NULL, "deconfig");
}
- bb_info_msg("Entering released state");
+ bb_simple_info_msg("entering released state");
+/*
+ * We can be here on: SIGUSR2,
+ * or on exit (SIGTERM) and -R "release on quit" is specified.
+ * Users requested to be notified in all cases, even if not in one
+ * of the states above.
+ */
+ udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_NONE);
- state = RELEASED;
+ client_data.state = RELEASED;
}
static uint8_t* alloc_dhcp_option(int code, const char *str, int extra)
bb_daemonize(0);
logmode &= ~LOGMODE_STDIO;
/* rewrite pidfile, as our pid is different now */
- write_pidfile(client_config.pidfile);
+ write_pidfile(client_data.pidfile);
}
#endif
//usage:# define IF_UDHCP_VERBOSE(...)
//usage:#endif
//usage:#define udhcpc_trivial_usage
-//usage: "[-fbq"IF_UDHCP_VERBOSE("v")IF_FEATURE_UDHCPC_ARPING("a")"oCRB] [-t N] [-T SEC] [-A SEC/-n]\n"
-//usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-r IP] [-s PROG] [-p PIDFILE]\n"
-//usage: " [-V VENDOR] [-x OPT:VAL]... [-O OPT]..."
+//usage: "[-fbq"IF_UDHCP_VERBOSE("v")"RB]"IF_FEATURE_UDHCPC_ARPING(" [-a[MSEC]]")" [-t N] [-T SEC] [-A SEC/-n]\n"
+//usage: " [-i IFACE]"IF_FEATURE_UDHCP_PORT(" [-P PORT]")" [-s PROG] [-p PIDFILE]\n"
+//usage: " [-oC] [-r IP] [-V VENDOR] [-F NAME] [-x OPT:VAL]... [-O OPT]..."
//usage:#define udhcpc_full_usage "\n"
-//usage: IF_LONG_OPTS(
-//usage: "\n -i,--interface IFACE Interface to use (default eth0)"
-//usage: "\n -p,--pidfile FILE Create pidfile"
-//usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
-//usage: "\n -B,--broadcast Request broadcast replies"
-//usage: "\n -t,--retries N Send up to N discover packets (default 3)"
-//usage: "\n -T,--timeout SEC Pause between packets (default 3)"
-//usage: "\n -A,--tryagain SEC Wait after failure (default 20)"
-//usage: "\n -n,--now Exit if lease is not obtained"
-//usage: "\n -q,--quit Exit after obtaining lease"
-//usage: "\n -R,--release Release IP on exit"
-//usage: "\n -f,--foreground Run in foreground"
-//usage: USE_FOR_MMU(
-//usage: "\n -b,--background Background if lease is not obtained"
-//usage: )
-//usage: "\n -S,--syslog Log to syslog too"
+//usage: "\n -i IFACE Interface to use (default eth0)"
//usage: IF_FEATURE_UDHCP_PORT(
-//usage: "\n -P,--client-port PORT Use PORT (default 68)"
-//usage: )
-//usage: IF_FEATURE_UDHCPC_ARPING(
-//usage: "\n -a,--arping Use arping to validate offered address"
-//usage: )
-//usage: "\n -O,--request-option OPT Request option OPT from server (cumulative)"
-//usage: "\n -o,--no-default-options Don't request any options (unless -O is given)"
-//usage: "\n -r,--request IP Request this IP address"
-//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
-//usage: "\n Examples of string, numeric, and hex byte opts:"
-//usage: "\n -x hostname:bbox - option 12"
-//usage: "\n -x lease:3600 - option 51 (lease time)"
-//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
-//usage: "\n -F,--fqdn NAME Ask server to update DNS mapping for NAME"
-//usage: "\n -V,--vendorclass VENDOR Vendor identifier (default 'udhcp VERSION')"
-//usage: "\n -C,--clientid-none Don't send MAC as client identifier"
-//usage: IF_UDHCP_VERBOSE(
-//usage: "\n -v Verbose"
-//usage: )
+//usage: "\n -P PORT Use PORT (default 68)"
//usage: )
-//usage: IF_NOT_LONG_OPTS(
-//usage: "\n -i IFACE Interface to use (default eth0)"
-//usage: "\n -p FILE Create pidfile"
//usage: "\n -s PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
+//usage: "\n -p FILE Create pidfile"
//usage: "\n -B Request broadcast replies"
//usage: "\n -t N Send up to N discover packets (default 3)"
//usage: "\n -T SEC Pause between packets (default 3)"
-//usage: "\n -A SEC Wait after failure (default 20)"
+//usage: "\n -A SEC Wait if lease is not obtained (default 20)"
+//usage: USE_FOR_MMU(
+//usage: "\n -b Background if lease is not obtained"
+//usage: )
//usage: "\n -n Exit if lease is not obtained"
//usage: "\n -q Exit after obtaining lease"
//usage: "\n -R Release IP on exit"
//usage: "\n -f Run in foreground"
-//usage: USE_FOR_MMU(
-//usage: "\n -b Background if lease is not obtained"
-//usage: )
//usage: "\n -S Log to syslog too"
-//usage: IF_FEATURE_UDHCP_PORT(
-//usage: "\n -P PORT Use PORT (default 68)"
-//usage: )
//usage: IF_FEATURE_UDHCPC_ARPING(
-//usage: "\n -a Use arping to validate offered address"
+//usage: "\n -a[MSEC] Validate offered address with ARP ping"
//usage: )
-//usage: "\n -O OPT Request option OPT from server (cumulative)"
-//usage: "\n -o Don't request any options (unless -O is given)"
//usage: "\n -r IP Request this IP address"
+//usage: "\n -o Don't request any options (unless -O is given)"
+//usage: "\n -O OPT Request option OPT from server (cumulative)"
//usage: "\n -x OPT:VAL Include option OPT in sent packets (cumulative)"
//usage: "\n Examples of string, numeric, and hex byte opts:"
//usage: "\n -x hostname:bbox - option 12"
//usage: "\n -x lease:3600 - option 51 (lease time)"
//usage: "\n -x 0x3d:0100BEEFC0FFEE - option 61 (client id)"
+//usage: "\n -x 14:'\"dumpfile\"' - option 14 (shell-quoted)"
//usage: "\n -F NAME Ask server to update DNS mapping for NAME"
//usage: "\n -V VENDOR Vendor identifier (default 'udhcp VERSION')"
//usage: "\n -C Don't send MAC as client identifier"
//usage: IF_UDHCP_VERBOSE(
//usage: "\n -v Verbose"
//usage: )
-//usage: )
//usage: "\nSignals:"
//usage: "\n USR1 Renew lease"
//usage: "\n USR2 Release lease"
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int udhcpc_main(int argc UNUSED_PARAM, char **argv)
{
- uint8_t *temp, *message;
+ uint8_t *message;
const char *str_V, *str_h, *str_F, *str_r;
+ IF_FEATURE_UDHCPC_ARPING(const char *str_a = "2000";)
IF_FEATURE_UDHCP_PORT(char *str_P;)
void *clientid_mac_ptr;
llist_t *list_O = NULL;
int timeout; /* must be signed */
unsigned already_waited_sec;
unsigned opt;
- int max_fd;
+ IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;)
int retval;
- fd_set rfds;
+
+ setup_common_bufsiz();
/* Default options */
IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
- client_config.interface = "eth0";
- client_config.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
+ client_data.interface = "eth0";
+ client_data.script = CONFIG_UDHCPC_DEFAULT_SCRIPT;
+ client_data.sockfd = -1;
str_V = "udhcp "BB_VER;
+ /* Make sure fd 0,1,2 are open */
+ /* Set up the signal pipe on fds 3,4 - must be before openlog() */
+ udhcp_sp_setup();
+
/* Parse command line */
- /* O,x: list; -T,-t,-A take numeric param */
- opt_complementary = "O::x::T+:t+:A+" IF_UDHCP_VERBOSE(":vv") ;
- IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
- opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:fB"
+ opt = getopt32long(argv, "^"
+ /* O,x: list; -T,-t,-A take numeric param */
+ "CV:H:h:F:i:np:qRr:s:T:+t:+SA:+O:*ox:*fB"
USE_FOR_MMU("b")
- IF_FEATURE_UDHCPC_ARPING("a")
+ IF_FEATURE_UDHCPC_ARPING("a::")
IF_FEATURE_UDHCP_PORT("P:")
"v"
+ "\0" IF_UDHCP_VERBOSE("vv") /* -v is a counter */
+ , udhcpc_longopts
, &str_V, &str_h, &str_h, &str_F
- , &client_config.interface, &client_config.pidfile, &str_r /* i,p */
- , &client_config.script /* s */
+ , &client_data.interface, &client_data.pidfile /* i,p */
+ , &str_r /* r */
+ , &client_data.script /* s */
, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
, &list_O
, &list_x
+ IF_FEATURE_UDHCPC_ARPING(, &str_a)
IF_FEATURE_UDHCP_PORT(, &str_P)
IF_UDHCP_VERBOSE(, &dhcp_verbose)
);
if (opt & (OPT_h|OPT_H)) {
//msg added 2011-11
- bb_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
- client_config.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
+ bb_simple_error_msg("option -h NAME is deprecated, use -x hostname:NAME");
+ client_data.hostname = alloc_dhcp_option(DHCP_HOST_NAME, str_h, 0);
}
if (opt & OPT_F) {
/* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
- client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
+ client_data.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
/* Flag bits: 0000NEOS
* S: 1 = Client requests server to update A RR in DNS as well as PTR
* O: 1 = Server indicates to client that DNS has been updated regardless
* N: 1 = Client requests server to not update DNS (S must be 0 then)
* Two [0] bytes which follow are deprecated and must be 0.
*/
- client_config.fqdn[OPT_DATA + 0] = 0x1;
- /*client_config.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
- /*client_config.fqdn[OPT_DATA + 2] = 0; */
+ client_data.fqdn[OPT_DATA + 0] = 0x1;
+ /*client_data.fqdn[OPT_DATA + 1] = 0; - xzalloc did it */
+ /*client_data.fqdn[OPT_DATA + 2] = 0; */
}
if (opt & OPT_r)
requested_ip = inet_addr(str_r);
SERVER_PORT = CLIENT_PORT - 1;
}
#endif
+ IF_FEATURE_UDHCPC_ARPING(arpping_ms = xatou(str_a);)
while (list_O) {
char *optstr = llist_pop(&list_O);
unsigned n = bb_strtou(optstr, NULL, 0);
if (errno || n > 254) {
- n = udhcp_option_idx(optstr);
+ n = udhcp_option_idx(optstr, dhcp_option_strings);
n = dhcp_optflags[n].code;
}
- client_config.opt_mask[n >> 3] |= 1 << (n & 7);
+ client_data.opt_mask[n >> 3] |= 1 << (n & 7);
}
if (!(opt & OPT_o)) {
unsigned i, n;
for (i = 0; (n = dhcp_optflags[i].code) != 0; i++) {
if (dhcp_optflags[i].flags & OPTION_REQ) {
- client_config.opt_mask[n >> 3] |= 1 << (n & 7);
+ client_data.opt_mask[n >> 3] |= 1 << (n & 7);
}
}
}
while (list_x) {
- char *optstr = llist_pop(&list_x);
- char *colon = strchr(optstr, ':');
- if (colon)
- *colon = ' ';
- /* now it looks similar to udhcpd's config file line:
- * "optname optval", using the common routine: */
- udhcp_str2optset(optstr, &client_config.options);
+ char *optstr = xstrdup(llist_pop(&list_x));
+ udhcp_str2optset(optstr, &client_data.options,
+ dhcp_optflags, dhcp_option_strings,
+ /*dhcpv6:*/ 0
+ );
+ free(optstr);
}
- if (udhcp_read_interface(client_config.interface,
- &client_config.ifindex,
+ if (udhcp_read_interface(client_data.interface,
+ &client_data.ifindex,
NULL,
- client_config.client_mac)
+ client_data.client_mac)
) {
return 1;
}
clientid_mac_ptr = NULL;
- if (!(opt & OPT_C) && !udhcp_find_option(client_config.options, DHCP_CLIENT_ID)) {
+ if (!(opt & OPT_C) && !udhcp_find_option(client_data.options, DHCP_CLIENT_ID)) {
/* not suppressed and not set, set the default client ID */
- client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
- client_config.clientid[OPT_DATA] = 1; /* type: ethernet */
- clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
- memcpy(clientid_mac_ptr, client_config.client_mac, 6);
+ client_data.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, "", 7);
+ client_data.clientid[OPT_DATA] = 1; /* type: ethernet */
+ clientid_mac_ptr = client_data.clientid + OPT_DATA+1;
+ memcpy(clientid_mac_ptr, client_data.client_mac, 6);
}
if (str_V[0] != '\0') {
- // can drop -V, str_V, client_config.vendorclass,
+ // can drop -V, str_V, client_data.vendorclass,
// but need to add "vendor" to the list of recognized
// string opts for this to work;
// and need to tweak add_client_options() too...
// ...so the question is, should we?
//bb_error_msg("option -V VENDOR is deprecated, use -x vendor:VENDOR");
- client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
+ client_data.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
}
#if !BB_MMU
logmode |= LOGMODE_SYSLOG;
}
- /* Make sure fd 0,1,2 are open */
- bb_sanitize_stdio();
- /* Equivalent of doing a fflush after every \n */
- setlinebuf(stdout);
/* Create pidfile */
- write_pidfile(client_config.pidfile);
+ write_pidfile(client_data.pidfile);
/* Goes to stdout (unless NOMMU) and possibly syslog */
- bb_info_msg("%s (v"BB_VER") started", applet_name);
- /* Set up the signal pipe */
- udhcp_sp_setup();
+ bb_simple_info_msg("started, v"BB_VER);
/* We want random_xid to be random... */
srand(monotonic_us());
- state = INIT_SELECTING;
+ client_data.state = INIT_SELECTING;
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
packet_num = 0;
* "continue" statements in code below jump to the top of the loop.
*/
for (;;) {
- struct timeval tv;
+ int tv;
+ struct pollfd pfds[2];
struct dhcp_packet packet;
/* silence "uninitialized!" warning */
unsigned timestamp_before_wait = timestamp_before_wait;
- //bb_error_msg("sockfd:%d, listen_mode:%d", sockfd, listen_mode);
+ //bb_error_msg("sockfd:%d, listen_mode:%d", client_data.sockfd, client_data.listen_mode);
/* Was opening raw or udp socket here
- * if (listen_mode != LISTEN_NONE && sockfd < 0),
+ * if (client_data.listen_mode != LISTEN_NONE && client_data.sockfd < 0),
* but on fast network renew responses return faster
* than we open sockets. Thus this code is moved
* to change_listen_mode(). Thus we open listen socket
* BEFORE we send renew request (see "case BOUND:"). */
- max_fd = udhcp_sp_fd_set(&rfds, sockfd);
+ udhcp_sp_fd_set(pfds, client_data.sockfd);
- tv.tv_sec = timeout - already_waited_sec;
- tv.tv_usec = 0;
+ tv = timeout - already_waited_sec;
retval = 0;
/* If we already timed out, fall through with retval = 0, else... */
- if ((int)tv.tv_sec > 0) {
- log1("Waiting on select %u seconds", (int)tv.tv_sec);
+ if (tv > 0) {
+ log1("waiting %u seconds", tv);
timestamp_before_wait = (unsigned)monotonic_sec();
- retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
+ retval = poll(pfds, 2, tv < INT_MAX/1000 ? tv * 1000 : INT_MAX);
if (retval < 0) {
/* EINTR? A signal was caught, don't panic */
if (errno == EINTR) {
already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
continue;
}
- /* Else: an error occured, panic! */
- bb_perror_msg_and_die("select");
+ /* Else: an error occurred, panic! */
+ bb_simple_perror_msg_and_die("poll");
}
}
* or if the status of the bridge changed).
* Refresh ifindex and client_mac:
*/
- if (udhcp_read_interface(client_config.interface,
- &client_config.ifindex,
+ if (udhcp_read_interface(client_data.interface,
+ &client_data.ifindex,
NULL,
- client_config.client_mac)
+ client_data.client_mac)
) {
goto ret0; /* iface is gone? */
}
if (clientid_mac_ptr)
- memcpy(clientid_mac_ptr, client_config.client_mac, 6);
+ memcpy(clientid_mac_ptr, client_data.client_mac, 6);
/* We will restart the wait in any case */
already_waited_sec = 0;
- switch (state) {
+ switch (client_data.state) {
case INIT_SELECTING:
if (!discover_retries || packet_num < discover_retries) {
if (packet_num == 0)
udhcp_run_script(NULL, "leasefail");
#if BB_MMU /* -b is not supported on NOMMU */
if (opt & OPT_b) { /* background if no lease */
- bb_info_msg("No lease, forking to background");
+ bb_simple_info_msg("no lease, forking to background");
client_background();
/* do not background again! */
- opt = ((opt & ~OPT_b) | OPT_f);
+ opt = ((opt & ~(OPT_b|OPT_n)) | OPT_f);
+ /* ^^^ also disables -n (-b takes priority over -n):
+ * ifup's default udhcpc options are -R -n,
+ * and users want to be able to add -b
+ * (in a config file) to make it background
+ * _and not exit_.
+ */
} else
#endif
if (opt & OPT_n) { /* abort if no lease */
- bb_info_msg("No lease, failing");
+ bb_simple_info_msg("no lease, failing");
retval = 1;
goto ret;
}
packet_num = 0;
continue;
case REQUESTING:
- if (!discover_retries || packet_num < discover_retries) {
+ if (packet_num < 3) {
/* send broadcast select packet */
send_select(xid, server_addr, requested_ip);
timeout = discover_timeout;
* were seen in the wild. Treat them similarly
* to "no response to discover" case */
change_listen_mode(LISTEN_RAW);
- state = INIT_SELECTING;
+ client_data.state = INIT_SELECTING;
goto leasefail;
case BOUND:
/* 1/2 lease passed, enter renewing state */
- state = RENEWING;
- client_config.first_secs = 0; /* make secs field count from 0 */
+ client_data.state = RENEWING;
+ client_data.first_secs = 0; /* make secs field count from 0 */
change_listen_mode(LISTEN_KERNEL);
- log1("Entering renew state");
+ log1s("entering renew state");
/* fall right through */
case RENEW_REQUESTED: /* manual (SIGUSR1) renew */
case_RENEW_REQUESTED:
case RENEWING:
- if (timeout > 60) {
+ if (timeout >= 60) {
/* send an unicast renew request */
/* Sometimes observed to fail (EADDRNOTAVAIL) to bind
* a new UDP socket for sending inside send_renew.
* Anyway, it does recover by eventually failing through
* into INIT_SELECTING state.
*/
- send_renew(xid, server_addr, requested_ip);
- timeout >>= 1;
- continue;
+ if (send_renew(xid, server_addr, requested_ip) >= 0) {
+ timeout >>= 1;
+//TODO: the timeout to receive an answer for our renew should not be selected
+//with "timeout = lease_seconds / 2; ...; timeout = timeout / 2": it is often huge.
+//Waiting e.g. 4*3600 seconds for a reply does not make sense
+//(if reply isn't coming, we keep an open socket for hours),
+//it should be something like 10 seconds.
+//Also, it's probably best to try sending renew in kernel mode a few (3-5) times
+//and fall back to raw mode if it does not work.
+ continue;
+ }
+ /* else: error sending.
+ * example: ENETUNREACH seen with server
+ * which gave us bogus server ID 1.1.1.1
+ * which wasn't reachable (and probably did not exist).
+ */
}
- /* Timed out, enter rebinding state */
- log1("Entering rebinding state");
- state = REBINDING;
+ /* Timed out or error, enter rebinding state */
+ log1s("entering rebinding state");
+ client_data.state = REBINDING;
/* fall right through */
case REBINDING:
/* Switch to bcast receive */
continue;
}
/* Timed out, enter init state */
- bb_info_msg("Lease lost, entering init state");
+ bb_simple_info_msg("lease lost, entering init state");
udhcp_run_script(NULL, "deconfig");
- state = INIT_SELECTING;
- client_config.first_secs = 0; /* make secs field count from 0 */
+ client_data.state = INIT_SELECTING;
+ client_data.first_secs = 0; /* make secs field count from 0 */
/*timeout = 0; - already is */
packet_num = 0;
continue;
/* yah, I know, *you* say it would never happen */
timeout = INT_MAX;
continue; /* back to main loop */
- } /* if select timed out */
+ } /* if poll timed out */
- /* select() didn't timeout, something happened */
+ /* poll() didn't timeout, something happened */
/* Is it a signal? */
- /* note: udhcp_sp_read checks FD_ISSET before reading */
- switch (udhcp_sp_read(&rfds)) {
+ switch (udhcp_sp_read()) {
case SIGUSR1:
- client_config.first_secs = 0; /* make secs field count from 0 */
+ client_data.first_secs = 0; /* make secs field count from 0 */
already_waited_sec = 0;
perform_renew();
- if (state == RENEW_REQUESTED) {
+ if (client_data.state == RENEW_REQUESTED) {
/* We might be either on the same network
* (in which case renew might work),
* or we might be on a completely different one
* For the second case, must make sure timeout
* is not too big, or else we can send
* futile renew requests for hours.
- * (Ab)use -A TIMEOUT value (usually 20 sec)
- * as a cap on the timeout.
*/
- if (timeout > tryagain_timeout)
- timeout = tryagain_timeout;
+ if (timeout > 60)
+ timeout = 60;
goto case_RENEW_REQUESTED;
}
/* Start things over */
timeout = INT_MAX;
continue;
case SIGTERM:
- bb_info_msg("Received SIGTERM");
+ bb_info_msg("received %s", "SIGTERM");
goto ret0;
}
/* Is it a packet? */
- if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds))
+ if (!pfds[1].revents)
continue; /* no */
{
int len;
/* A packet is ready, read it */
- if (listen_mode == LISTEN_KERNEL)
- len = udhcp_recv_kernel_packet(&packet, sockfd);
+ if (client_data.listen_mode == LISTEN_KERNEL)
+ len = udhcp_recv_kernel_packet(&packet, client_data.sockfd);
else
- len = udhcp_recv_raw_packet(&packet, sockfd);
+ len = udhcp_recv_raw_packet(&packet, client_data.sockfd);
if (len == -1) {
/* Error is severe, reopen socket */
- bb_info_msg("Read error: %s, reopening socket", strerror(errno));
+ bb_error_msg("read error: "STRERROR_FMT", reopening socket" STRERROR_ERRNO);
sleep(discover_timeout); /* 3 seconds by default */
- change_listen_mode(listen_mode); /* just close and reopen */
+ change_listen_mode(client_data.listen_mode); /* just close and reopen */
}
/* If this packet will turn out to be unrelated/bogus,
* we will go back and wait for next one.
/* Ignore packets that aren't for us */
if (packet.hlen != 6
- || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
+ || memcmp(packet.chaddr, client_data.client_mac, 6) != 0
) {
//FIXME: need to also check that last 10 bytes are zero
- log1("chaddr does not match, ignoring packet"); // log2?
+ log1("chaddr does not match%s", ", ignoring packet"); // log2?
continue;
}
message = udhcp_get_option(&packet, DHCP_MESSAGE_TYPE);
if (message == NULL) {
- bb_error_msg("no message type option, ignoring packet");
+ bb_info_msg("no message type option%s", ", ignoring packet");
continue;
}
- switch (state) {
+ switch (client_data.state) {
case INIT_SELECTING:
/* Must be a DHCPOFFER */
if (*message == DHCPOFFER) {
+ uint8_t *temp;
+
/* What exactly is server's IP? There are several values.
* Example DHCP offer captured with tchdump:
*
* might work too.
* "Next server" and router are definitely wrong ones to use, though...
*/
- temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
+/* We used to ignore packets without DHCP_SERVER_ID.
+ * I've got user reports from people who run "address-less" servers.
+ * They either supply DHCP_SERVER_ID of 0.0.0.0 or don't supply it at all.
+ * They say ISC DHCP client supports this case.
+ */
+ server_addr = 0;
+ temp = udhcp_get_option32(&packet, DHCP_SERVER_ID);
if (!temp) {
- bb_error_msg("no server ID, ignoring packet");
- continue;
- /* still selecting - this server looks bad */
+ bb_simple_info_msg("no server ID, using 0.0.0.0");
+ } else {
+ /* it IS unaligned sometimes, don't "optimize" */
+ move_from_unaligned32(server_addr, temp);
}
- /* it IS unaligned sometimes, don't "optimize" */
- move_from_unaligned32(server_addr, temp);
/*xid = packet.xid; - already is */
requested_ip = packet.yiaddr;
/* enter requesting state */
- state = REQUESTING;
+ client_data.state = REQUESTING;
timeout = 0;
packet_num = 0;
already_waited_sec = 0;
case RENEW_REQUESTED:
case REBINDING:
if (*message == DHCPACK) {
+ unsigned start;
uint32_t lease_seconds;
struct in_addr temp_addr;
+ uint8_t *temp;
- temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
+ temp = udhcp_get_option32(&packet, DHCP_LEASE_TIME);
if (!temp) {
- bb_error_msg("no lease time with ACK, using 1 hour lease");
+ bb_simple_info_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);
/* paranoia: must not be too small and not prone to overflows */
- if (lease_seconds < 0x10)
- lease_seconds = 0x10;
- if (lease_seconds >= 0x10000000)
- lease_seconds = 0x0fffffff;
+ /* timeout > 60 - ensures at least one unicast renew attempt */
+ if (lease_seconds < 2 * 61)
+ lease_seconds = 2 * 61;
+ //if (lease_seconds > 0x7fffffff)
+ // lease_seconds = 0x7fffffff;
+ //^^^not necessary since "timeout = lease_seconds / 2"
+ //does not overflow even for 0xffffffff.
}
#if ENABLE_FEATURE_UDHCPC_ARPING
if (opt & OPT_a) {
if (!arpping(packet.yiaddr,
NULL,
(uint32_t) 0,
- client_config.client_mac,
- client_config.interface)
+ client_data.client_mac,
+ client_data.interface,
+ arpping_ms)
) {
- bb_info_msg("Offered address is in use "
+ bb_simple_info_msg("offered address is in use "
"(got ARP reply), declining");
send_decline(/*xid,*/ server_addr, packet.yiaddr);
- if (state != REQUESTING)
+ if (client_data.state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
- state = INIT_SELECTING;
- client_config.first_secs = 0; /* make secs field count from 0 */
+ client_data.state = INIT_SELECTING;
+ client_data.first_secs = 0; /* make secs field count from 0 */
requested_ip = 0;
timeout = tryagain_timeout;
packet_num = 0;
}
#endif
/* enter bound state */
- timeout = lease_seconds / 2;
temp_addr.s_addr = packet.yiaddr;
- bb_info_msg("Lease of %s obtained, lease time %u",
+ 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 == REQUESTING ? "bound" : "renew");
- state = BOUND;
+ start = monotonic_sec();
+ udhcp_run_script(&packet, client_data.state == REQUESTING ? "bound" : "renew");
+ already_waited_sec = (unsigned)monotonic_sec() - start;
+ timeout = lease_seconds / 2;
+ if ((unsigned)timeout < already_waited_sec) {
+ /* Something went wrong. Back to discover state */
+ timeout = already_waited_sec = 0;
+ }
+
+ client_data.state = BOUND;
change_listen_mode(LISTEN_NONE);
if (opt & OPT_q) { /* quit after lease */
goto ret0;
#endif
/* make future renew packets use different xid */
/* xid = random_xid(); ...but why bother? */
- already_waited_sec = 0;
+
continue; /* back to main loop */
}
if (*message == DHCPNAK) {
+ /* If network has more than one DHCP server,
+ * "wrong" server can reply first, with a NAK.
+ * Do not interpret it as a NAK from "our" server.
+ */
+ if (server_addr != 0) {
+ uint32_t svid;
+ uint8_t *temp;
+
+ temp = udhcp_get_option32(&packet, DHCP_SERVER_ID);
+ if (!temp) {
+ non_matching_svid:
+ log1("received DHCP NAK with wrong"
+ " server ID%s", ", ignoring packet");
+ continue;
+ }
+ move_from_unaligned32(svid, temp);
+ if (svid != server_addr)
+ goto non_matching_svid;
+ }
/* return to init state */
- bb_info_msg("Received DHCP NAK");
+ bb_info_msg("received %s", "DHCP NAK");
udhcp_run_script(&packet, "nak");
- if (state != REQUESTING)
+ if (client_data.state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
change_listen_mode(LISTEN_RAW);
sleep(3); /* avoid excessive network traffic */
- state = INIT_SELECTING;
- client_config.first_secs = 0; /* make secs field count from 0 */
+ client_data.state = INIT_SELECTING;
+ client_data.first_secs = 0; /* make secs field count from 0 */
requested_ip = 0;
timeout = 0;
packet_num = 0;
perform_release(server_addr, requested_ip);
retval = 0;
ret:
- /*if (client_config.pidfile) - remove_pidfile has its own check */
- remove_pidfile(client_config.pidfile);
+ /*if (client_data.pidfile) - remove_pidfile has its own check */
+ remove_pidfile(client_data.pidfile);
return retval;
}
projects / oweals / busybox.git / blobdiff