/* option points to OPT_DATA, need to go back and get OPT_LEN */
len = option[OPT_LEN - OPT_DATA];
+
type = optflag->flags & OPTION_TYPE_MASK;
optlen = dhcp_option_lengths[type];
upper_length = len_of_option_as_string[type] * ((unsigned)len / (unsigned)optlen);
dest += sprintf(ret, "%s=", opt_name);
while (len >= optlen) {
+ unsigned ip_ofs = 0;
+
switch (type) {
case OPTION_IP_PAIR:
dest += sprint_nip(dest, "", option);
*dest++ = '/';
- option += 4;
- optlen = 4;
+ ip_ofs = 4;
+ /* fall through */
case OPTION_IP:
- dest += sprint_nip(dest, "", option);
-// TODO: it can be a list only if (optflag->flags & OPTION_LIST).
-// Should we bail out/warn if we see multi-ip option which is
-// not allowed to be such? For example, DHCP_BROADCAST...
+ dest += sprint_nip(dest, "", option + ip_ofs);
break;
// case OPTION_BOOLEAN:
// dest += sprintf(dest, *option ? "yes" : "no");
} /* switch */
option += optlen;
len -= optlen;
- if (len <= 0)
+// TODO: it can be a list only if (optflag->flags & OPTION_LIST).
+// Should we bail out/warn if we see multi-ip option which is
+// not allowed to be such (for example, DHCP_BROADCAST)? -
+ if (len <= 0 /* || !(optflag->flags & OPTION_LIST) */)
break;
*dest++ = ' ';
*dest = '\0';
/* put all the parameters into the environment */
static char **fill_envp(struct dhcp_packet *packet)
{
- int num_options = 0;
+ int envc;
int i;
char **envp, **curr;
const char *opt_name;
uint8_t *temp;
- uint8_t over = 0;
-
+ uint8_t overload = 0;
+
+ /* We need 6 elements for:
+ * "interface=IFACE"
+ * "ip=N.N.N.N" from packet->yiaddr
+ * "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;
+ /* +1 element for each option, +2 for subnet option: */
if (packet) {
for (i = 0; dhcp_optflags[i].code; i++) {
if (udhcp_get_option(packet, dhcp_optflags[i].code)) {
- num_options++;
if (dhcp_optflags[i].code == DHCP_SUBNET)
- num_options++; /* for mton */
+ envc++; /* for mton */
+ envc++;
}
}
- if (packet->siaddr_nip)
- num_options++;
temp = udhcp_get_option(packet, DHCP_OPTION_OVERLOAD);
if (temp)
- over = *temp;
- if (!(over & FILE_FIELD) && packet->file[0])
- num_options++;
- if (!(over & SNAME_FIELD) && packet->sname[0])
- num_options++;
+ overload = *temp;
}
+ curr = envp = xzalloc(sizeof(char *) * envc);
- curr = envp = xzalloc(sizeof(char *) * (num_options + 3));
*curr = xasprintf("interface=%s", client_config.interface);
putenv(*curr++);
- if (packet == NULL)
+ if (!packet)
return envp;
*curr = xmalloc(sizeof("ip=255.255.255.255"));
goto next;
*curr = xmalloc_optname_optval(temp, &dhcp_optflags[i], opt_name);
putenv(*curr++);
-
- /* Fill in a subnet bits option for things like /24 */
if (dhcp_optflags[i].code == DHCP_SUBNET) {
+ /* Subnet option: make things like "$ip/$mask" possible */
uint32_t subnet;
move_from_unaligned32(subnet, temp);
*curr = xasprintf("mask=%d", mton(subnet));
sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
putenv(*curr++);
}
- if (!(over & FILE_FIELD) && packet->file[0]) {
+ if (!(overload & FILE_FIELD) && packet->file[0]) {
/* watch out for invalid packets */
*curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
putenv(*curr++);
}
- if (!(over & SNAME_FIELD) && packet->sname[0]) {
+ if (!(overload & SNAME_FIELD) && packet->sname[0]) {
/* watch out for invalid packets */
*curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
putenv(*curr++);
for (curr = envp; *curr; curr++) {
log2(" %s", *curr);
- bb_unsetenv(*curr);
- free(*curr);
+ bb_unsetenv_and_free(*curr);
}
free(envp);
}
/* Initialize the packet with the proper defaults */
static void init_packet(struct dhcp_packet *packet, char type)
{
+ /* Fill in: op, htype, hlen, cookie fields; message type option: */
udhcp_init_header(packet, type);
+
+ packet->xid = random_xid();
+
memcpy(packet->chaddr, client_config.client_mac, 6);
if (client_config.clientid)
udhcp_add_binary_option(packet, client_config.clientid);
+}
+
+static void add_client_options(struct dhcp_packet *packet)
+{
+ uint8_t c;
+ int i, end, len;
+
+ udhcp_add_simple_option(packet, DHCP_MAX_SIZE, htons(IP_UDP_DHCP_SIZE));
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 (type != DHCPDECLINE
- && type != DHCPRELEASE
- && client_config.vendorclass
- ) {
+ if (client_config.vendorclass)
udhcp_add_binary_option(packet, client_config.vendorclass);
- }
-}
-static void add_client_options(struct dhcp_packet *packet)
-{
/* Add a "param req" option with the list of options we'd like to have
* from stubborn DHCP servers. Pull the data from the struct in common.c.
* No bounds checking because it goes towards the head of the packet. */
- uint8_t c;
- int end = udhcp_end_option(packet->options);
- int i, len = 0;
-
+ end = udhcp_end_option(packet->options);
+ len = 0;
for (i = 0; (c = dhcp_optflags[i].code) != 0; i++) {
if (( (dhcp_optflags[i].flags & OPTION_REQ)
&& !client_config.no_default_options
{
struct dhcp_packet packet;
+ /* Fill in: op, htype, hlen, cookie, chaddr fields,
+ * random xid field (we override it below),
+ * client-id option (unless -C), message type option:
+ */
init_packet(&packet, DHCPDISCOVER);
+
packet.xid = xid;
if (requested)
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
- /* Explicitly saying that we want RFC-compliant packets helps
- * some buggy DHCP servers to NOT send bigger packets */
- udhcp_add_simple_option(&packet, DHCP_MAX_SIZE, htons(576));
+
+ /* Add options: maxsize,
+ * optionally: hostname, fqdn, vendorclass,
+ * "param req" option according to -O, options specified with -x
+ */
add_client_options(&packet);
bb_info_msg("Sending discover...");
struct dhcp_packet packet;
struct in_addr addr;
+/*
+ * RFC 2131 4.3.2 DHCPREQUEST message
+ * ...
+ * If the DHCPREQUEST message contains a 'server identifier'
+ * option, the message is in response to a DHCPOFFER message.
+ * Otherwise, the message is a request to verify or extend an
+ * existing lease. If the client uses a 'client identifier'
+ * in a DHCPREQUEST message, it MUST use that same 'client identifier'
+ * in all subsequent messages. If the client included a list
+ * of requested parameters in a DHCPDISCOVER message, it MUST
+ * include that list in all subsequent messages.
+ */
+ /* Fill in: op, htype, hlen, cookie, chaddr fields,
+ * random xid field (we override it below),
+ * client-id option (unless -C), message type option:
+ */
init_packet(&packet, DHCPREQUEST);
+
packet.xid = xid;
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
+
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
+
+ /* Add options: maxsize,
+ * optionally: hostname, fqdn, vendorclass,
+ * "param req" option according to -O, and options specified with -x
+ */
add_client_options(&packet);
addr.s_addr = requested;
{
struct dhcp_packet packet;
+/*
+ * RFC 2131 4.3.2 DHCPREQUEST message
+ * ...
+ * DHCPREQUEST generated during RENEWING state:
+ *
+ * 'server identifier' MUST NOT be filled in, 'requested IP address'
+ * option MUST NOT be filled in, 'ciaddr' MUST be filled in with
+ * client's IP address. In this situation, the client is completely
+ * configured, and is trying to extend its lease. This message will
+ * be unicast, so no relay agents will be involved in its
+ * transmission. Because 'giaddr' is therefore not filled in, the
+ * DHCP server will trust the value in 'ciaddr', and use it when
+ * replying to the client.
+ */
+ /* Fill in: op, htype, hlen, cookie, chaddr fields,
+ * random xid field (we override it below),
+ * client-id option (unless -C), message type option:
+ */
init_packet(&packet, DHCPREQUEST);
+
packet.xid = xid;
packet.ciaddr = ciaddr;
+
+ /* Add options: maxsize,
+ * optionally: hostname, fqdn, vendorclass,
+ * "param req" option according to -O, and options specified with -x
+ */
add_client_options(&packet);
bb_info_msg("Sending renew...");
{
struct dhcp_packet packet;
+ /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
+ * client-id option (unless -C), message type option:
+ */
init_packet(&packet, DHCPDECLINE);
+
+ /* RFC 2131 says DHCPDECLINE's xid is randomly selected by client,
+ * but in case the server is buggy and wants DHCPDECLINE's xid
+ * to match the xid which started entire handshake,
+ * we use the same xid we used in initial DHCPDISCOVER:
+ */
packet.xid = xid;
+ /* DHCPDECLINE uses "requested ip", not ciaddr, to store offered IP */
udhcp_add_simple_option(&packet, DHCP_REQUESTED_IP, requested);
+
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
bb_info_msg("Sending decline...");
{
struct dhcp_packet packet;
+ /* Fill in: op, htype, hlen, cookie, chaddr, random xid fields,
+ * client-id option (unless -C), message type option:
+ */
init_packet(&packet, DHCPRELEASE);
- packet.xid = random_xid();
+
+ /* DHCPRELEASE uses ciaddr, not "requested ip", to store IP being released */
packet.ciaddr = ciaddr;
udhcp_add_simple_option(&packet, DHCP_SERVER_ID, server);
}
#endif
+//usage:#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
+//usage:# define IF_UDHCP_VERBOSE(...) __VA_ARGS__
+//usage:#else
+//usage:# define IF_UDHCP_VERBOSE(...)
+//usage:#endif
+//usage:#define udhcpc_trivial_usage
+//usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCR] [-i IFACE] [-r IP] [-s PROG] [-p PIDFILE]\n"
+//usage: " [-H HOSTNAME] [-V VENDOR] [-x OPT:VAL]... [-O OPT]..." IF_FEATURE_UDHCP_PORT(" [-P N]")
+//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 -t,--retries N Send up to N discover packets"
+//usage: "\n -T,--timeout N Pause between packets (default 3 seconds)"
+//usage: "\n -A,--tryagain N Wait N seconds after failure (default 20)"
+//usage: "\n -f,--foreground Run in foreground"
+//usage: USE_FOR_MMU(
+//usage: "\n -b,--background Background if lease is not obtained"
+//usage: )
+//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 -S,--syslog Log to syslog too"
+//usage: IF_FEATURE_UDHCP_PORT(
+//usage: "\n -P,--client-port N Use port N (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 -H,-h,--hostname NAME Send NAME as client hostname (default none)"
+//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: )
+//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 -t N Send up to N discover packets"
+//usage: "\n -T N Pause between packets (default 3 seconds)"
+//usage: "\n -A N Wait N seconds (default 20) after failure"
+//usage: "\n -f Run in foreground"
+//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 -S Log to syslog too"
+//usage: IF_FEATURE_UDHCP_PORT(
+//usage: "\n -P N Use port N (default 68)"
+//usage: )
+//usage: IF_FEATURE_UDHCPC_ARPING(
+//usage: "\n -a Use arping to validate offered address"
+//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 -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 NAME Ask server to update DNS mapping for NAME"
+//usage: "\n -H,-h NAME Send NAME as client hostname (default none)"
+//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: )
+
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int udhcpc_main(int argc UNUSED_PARAM, char **argv)
{
uint8_t *temp, *message;
- const char *str_c, *str_V, *str_h, *str_F, *str_r;
+ const char *str_V, *str_h, *str_F, *str_r;
IF_FEATURE_UDHCP_PORT(char *str_P;)
llist_t *list_O = NULL;
llist_t *list_x = NULL;
#if ENABLE_LONG_OPTS
static const char udhcpc_longopts[] ALIGN1 =
- "clientid\0" Required_argument "c"
"clientid-none\0" No_argument "C"
"vendorclass\0" Required_argument "V"
"hostname\0" Required_argument "H"
;
#endif
enum {
- OPT_c = 1 << 0,
- OPT_C = 1 << 1,
- OPT_V = 1 << 2,
- OPT_H = 1 << 3,
- OPT_h = 1 << 4,
- OPT_F = 1 << 5,
- OPT_i = 1 << 6,
- OPT_n = 1 << 7,
- OPT_p = 1 << 8,
- OPT_q = 1 << 9,
- OPT_R = 1 << 10,
- OPT_r = 1 << 11,
- OPT_s = 1 << 12,
- OPT_T = 1 << 13,
- OPT_t = 1 << 14,
- OPT_S = 1 << 15,
- OPT_A = 1 << 16,
- OPT_O = 1 << 17,
- OPT_o = 1 << 18,
- OPT_x = 1 << 19,
- OPT_f = 1 << 20,
+ OPT_C = 1 << 0,
+ OPT_V = 1 << 1,
+ OPT_H = 1 << 2,
+ OPT_h = 1 << 3,
+ OPT_F = 1 << 4,
+ OPT_i = 1 << 5,
+ OPT_n = 1 << 6,
+ OPT_p = 1 << 7,
+ OPT_q = 1 << 8,
+ OPT_R = 1 << 9,
+ OPT_r = 1 << 10,
+ OPT_s = 1 << 11,
+ OPT_T = 1 << 12,
+ OPT_t = 1 << 13,
+ OPT_S = 1 << 14,
+ OPT_A = 1 << 15,
+ OPT_O = 1 << 16,
+ OPT_o = 1 << 17,
+ OPT_x = 1 << 18,
+ OPT_f = 1 << 19,
/* The rest has variable bit positions, need to be clever */
- OPTBIT_f = 20,
+ OPTBIT_f = 19,
USE_FOR_MMU( OPTBIT_b,)
IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
IF_FEATURE_UDHCP_PORT( OPTBIT_P,)
str_V = "udhcp "BB_VER;
/* Parse command line */
- /* Cc: mutually exclusive; O,x: list; -T,-t,-A take numeric param */
- opt_complementary = "c--C:C--c:O::x::T+:t+:A+"
+ /* O,x: list; -T,-t,-A take numeric param */
+ opt_complementary = "O::x::T+:t+:A+"
#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
":vv"
#endif
;
IF_LONG_OPTS(applet_long_options = udhcpc_longopts;)
- opt = getopt32(argv, "c:CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:f"
+ opt = getopt32(argv, "CV:H:h:F:i:np:qRr:s:T:t:SA:O:ox:f"
USE_FOR_MMU("b")
IF_FEATURE_UDHCPC_ARPING("a")
IF_FEATURE_UDHCP_PORT("P:")
"v"
- , &str_c, &str_V, &str_h, &str_h, &str_F
+ , &str_V, &str_h, &str_h, &str_F
, &client_config.interface, &client_config.pidfile, &str_r /* i,p */
, &client_config.script /* s */
, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
return 1;
}
- if (opt & OPT_c) {
- client_config.clientid = alloc_dhcp_option(DHCP_CLIENT_ID, str_c, 0);
- } else if (!(opt & OPT_C)) {
- /* not set and not suppressed, set the default client ID */
+ if (!(opt & OPT_C) && !udhcp_find_option(client_config.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 */
memcpy(client_config.clientid + OPT_DATA+1, client_config.client_mac, 6);
* resend discover/renew/whatever
*/
if (retval == 0) {
+ /* When running on a bridge, the ifindex may have changed
+ * (e.g. if member interfaces were added/removed
+ * or if the status of the bridge changed).
+ * Refresh ifindex and client_mac:
+ */
+ udhcp_read_interface(client_config.interface,
+ &client_config.ifindex,
+ NULL,
+ client_config.client_mac);
+
/* We will restart the wait in any case */
already_waited_sec = 0;
/* Ignore packets that aren't for us */
if (packet.hlen != 6
- || memcmp(packet.chaddr, client_config.client_mac, 6)
+ || memcmp(packet.chaddr, client_config.client_mac, 6) != 0
) {
//FIXME: need to also check that last 10 bytes are zero
log1("chaddr does not match, ignoring packet"); // log2?
}
/* it IS unaligned sometimes, don't "optimize" */
move_from_unaligned32(server_addr, temp);
- xid = packet.xid;
+ /*xid = packet.xid; - already is */
requested_ip = packet.yiaddr;
/* enter requesting state */