#include "dhcpc.h"
#include <netinet/if_ether.h>
-#include <netpacket/packet.h>
#include <linux/filter.h>
+#include <linux/if_packet.h>
-/* struct client_config_t client_config is in bb_common_bufsiz1 */
+/* "struct client_config_t client_config" is in bb_common_bufsiz1 */
#if ENABLE_LONG_OPTS
"request\0" Required_argument "r"
"script\0" Required_argument "s"
"timeout\0" Required_argument "T"
- "version\0" No_argument "v"
"retries\0" Required_argument "t"
"tryagain\0" Required_argument "A"
"syslog\0" No_argument "S"
[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_STRING ] = 1,
+ [OPTION_STRING_HOST ] = 1,
#if ENABLE_FEATURE_UDHCP_RFC3397
[OPTION_DNS_STRING ] = 1, /* unused */
/* Hmmm, this severely overestimates size if SIP_SERVERS option
return sprintf(dest, "%s%u.%u.%u.%u", pre, ip[0], ip[1], ip[2], ip[3]);
}
-static int sprint_nip6(char *dest, const char *pre, const uint8_t *ip)
-{
- char hexstrbuf[16 * 2];
- bin2hex(hexstrbuf, (void*)ip, 16);
- return sprintf(dest, "%s"
- "%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s:%.4s",
- pre,
- hexstrbuf + 0 * 4,
- hexstrbuf + 1 * 4,
- hexstrbuf + 2 * 4,
- hexstrbuf + 3 * 4,
- hexstrbuf + 4 * 4,
- hexstrbuf + 5 * 4,
- hexstrbuf + 6 * 4,
- hexstrbuf + 7 * 4
- );
-}
-
/* really simple implementation, just count the bits */
static int mton(uint32_t mask)
{
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
+ */
+/* 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"
+ * 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++;
+ }
+}
+
/* Create "opt_name=opt_value" string */
static NOINLINE char *xmalloc_optname_optval(uint8_t *option, const struct dhcp_optflag *optflag, const char *opt_name)
{
int len, type, optlen;
char *dest, *ret;
- /* option points to OPT_DATA, need to go back and get OPT_LEN */
- len = option[OPT_LEN - OPT_DATA];
+ /* option points to OPT_DATA, need to go back to get OPT_LEN */
+ len = option[-OPT_DATA + OPT_LEN];
type = optflag->flags & OPTION_TYPE_MASK;
optlen = dhcp_option_lengths[type];
dest += sprintf(ret, "%s=", opt_name);
while (len >= optlen) {
- unsigned ip_ofs = 0;
-
switch (type) {
+ case OPTION_IP:
case OPTION_IP_PAIR:
dest += sprint_nip(dest, "", option);
- *dest++ = '/';
- ip_ofs = 4;
- /* fall through */
- case OPTION_IP:
- dest += sprint_nip(dest, "", option + ip_ofs);
+ if (type == OPTION_IP)
+ break;
+ dest += sprint_nip(dest, "/", option + 4);
break;
// case OPTION_BOOLEAN:
// dest += sprintf(dest, *option ? "yes" : "no");
dest += sprintf(dest, type == OPTION_U32 ? "%lu" : "%ld", (unsigned long) ntohl(val_u32));
break;
}
+ /* Note: options which use 'return' instead of 'break'
+ * (for example, OPTION_STRING) skip the code which handles
+ * the case of list of options.
+ */
case OPTION_STRING:
+ case OPTION_STRING_HOST:
memcpy(dest, option, len);
dest[len] = '\0';
- return ret; /* Short circuit this case */
+ if (type == OPTION_STRING_HOST && !good_hostname(dest))
+ safe_strncpy(dest, "bad", len);
+ return ret;
case OPTION_STATIC_ROUTES: {
/* Option binary format:
* mask [one byte, 0..32]
return ret;
}
- case OPTION_6RD: {
+ case OPTION_6RD:
/* Option binary format (see RFC 5969):
- * 0 1 2 3
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ * 0 1 2 3
+ * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | OPTION_6RD | option-length | IPv4MaskLen | 6rdPrefixLen |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | |
* | 6rdPrefix |
- * | (16 octets) |
- * | |
- * | |
- * | |
+ * ... (16 octets) ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | 6rdBRIPv4Address(es) |
- * . .
- * . .
- * . .
+ * ... 6rdBRIPv4Address(es) ...
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *
* We convert it to a string
* "IPv4MaskLen 6rdPrefixLen 6rdPrefix 6rdBRIPv4Address..."
- */
-
- /* Sanity check: ensure that our length is at least 22 bytes, that
+ *
+ * Sanity check: ensure that our length is at least 22 bytes, that
* IPv4MaskLen <= 32,
* 6rdPrefixLen <= 128,
* 6rdPrefixLen + (32 - IPv4MaskLen) <= 128
* (2nd condition need no check - it follows from 1st and 3rd).
- * If any of these requirements is not fulfilled, return with empty
- * value.
+ * Else, return envvar with empty value ("optname=")
*/
- if (len >= 22
+ if (len >= (1 + 1 + 16 + 4)
&& option[0] <= 32
&& (option[1] + 32 - option[0]) <= 128
) {
/* 6rdPrefixLen */
dest += sprintf(dest, "%u ", *option++);
/* 6rdPrefix */
- dest += sprint_nip6(dest, "", option);
+ dest += sprint_nip6(dest, /* "", */ option);
option += 16;
- len -= 1 + 1 + 16;
- /* 6rdBRIPv4Address(es) */
+ 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;
+ len -= 4; /* do we have yet another 4+ bytes? */
if (len < 0)
- break;
+ break; /* no */
}
}
return ret;
- }
#if ENABLE_FEATURE_UDHCP_RFC3397
case OPTION_DNS_STRING:
/* unpack option into dest; use ret for prefix (i.e., "optname=") */
return ret;
#endif
} /* switch */
+
+ /* If we are here, try to format any remaining data
+ * in the option as another, similarly-formatted option
+ */
option += optlen;
len -= optlen;
// 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) */)
+ if (len < optlen /* || !(optflag->flags & OPTION_LIST) */)
break;
*dest++ = ' ';
*dest = '\0';
- }
+ } /* while */
+
return ret;
}
/* +1 element for each option, +2 for subnet option: */
if (packet) {
/* note: do not search for "pad" (0) and "end" (255) options */
+//TODO: change logic to scan packet _once_
for (i = 1; i < 255; i++) {
temp = udhcp_get_option(packet, i);
if (temp) {
if (i == DHCP_OPTION_OVERLOAD)
overload = *temp;
else if (i == DHCP_SUBNET)
- envc++; /* for mton */
+ envc++; /* for $mask */
envc++;
/*if (i != DHCP_MESSAGE_TYPE)*/
FOUND_OPTS(i) |= BMASK(i);
if (!packet)
return envp;
+ /* Export BOOTP fields. Fields we don't (yet?) export:
+ * uint8_t op; // always BOOTREPLY
+ * uint8_t htype; // hardware address type. 1 = 10mb ethernet
+ * uint8_t hlen; // hardware address length
+ * uint8_t hops; // used by relay agents only
+ * uint32_t xid;
+ * 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
+ * uint8_t chaddr[16]; // link-layer client hardware address (MAC)
+ * TODO: export gateway_nip as $giaddr?
+ */
+ /* Most important one: yiaddr as $ip */
*curr = xmalloc(sizeof("ip=255.255.255.255"));
sprint_nip(*curr, "ip=", (uint8_t *) &packet->yiaddr);
putenv(*curr++);
+ if (packet->siaddr_nip) {
+ /* IP address of next server to use in bootstrap */
+ *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
+ sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_nip);
+ putenv(*curr++);
+ }
+ if (!(overload & FILE_FIELD) && packet->file[0]) {
+ /* watch out for invalid packets */
+ *curr = xasprintf("boot_file=%."DHCP_PKT_FILE_LEN_STR"s", packet->file);
+ putenv(*curr++);
+ }
+ if (!(overload & SNAME_FIELD) && packet->sname[0]) {
+ /* watch out for invalid packets */
+ *curr = xasprintf("sname=%."DHCP_PKT_SNAME_LEN_STR"s", packet->sname);
+ putenv(*curr++);
+ }
+ /* Export known DHCP options */
opt_name = dhcp_option_strings;
i = 0;
while (*opt_name) {
/* Subnet option: make things like "$ip/$mask" possible */
uint32_t subnet;
move_from_unaligned32(subnet, temp);
- *curr = xasprintf("mask=%d", mton(subnet));
+ *curr = xasprintf("mask=%u", mton(subnet));
putenv(*curr++);
}
next:
opt_name += strlen(opt_name) + 1;
i++;
}
- if (packet->siaddr_nip) {
- *curr = xmalloc(sizeof("siaddr=255.255.255.255"));
- sprint_nip(*curr, "siaddr=", (uint8_t *) &packet->siaddr_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);
- putenv(*curr++);
- }
- 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++);
- }
- /* Handle unknown options */
+ /* Export unknown options */
for (i = 0; i < 256;) {
BITMAP bitmap = FOUND_OPTS(i);
if (!bitmap) {
}
i++;
}
+
return envp;
}
char **envp, **curr;
char *argv[3];
- if (client_config.script == NULL)
- return;
-
envp = fill_envp(packet);
/* call script */
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));
* No bounds checking because it goes towards the head of the packet. */
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
- )
- || (client_config.opt_mask[c >> 3] & (1 << (c & 7)))
- ) {
- packet->options[end + OPT_DATA + len] = c;
+ for (i = 1; i < DHCP_END; i++) {
+ if (client_config.opt_mask[i >> 3] & (1 << (i & 7))) {
+ packet->options[end + OPT_DATA + len] = i;
len++;
}
}
// if (client_config.boot_file)
// strncpy((char*)packet->file, client_config.boot_file, sizeof(packet->file) - 1);
}
+
+ // This will be needed if we remove -V VENDOR_STR in favor of
+ // -x vendor:VENDOR_STR
+ //if (!udhcp_find_option(packet.options, DHCP_VENDOR))
+ // /* not set, set the default vendor ID */
+ // ...add (DHCP_VENDOR, "udhcp "BB_VER) opt...
}
/* RFC 2131
client_config.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_config_ifindex(packet);
+}
+
/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
/* NOINLINE: limit stack usage in caller */
static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
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);
+ return bcast_or_ucast(&packet, ciaddr, server);
}
#if ENABLE_FEATURE_UDHCPC_ARPING
/* Broadcast a DHCP decline message */
/* NOINLINE: limit stack usage in caller */
-static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
+static NOINLINE int send_decline(/*uint32_t xid,*/ uint32_t server, uint32_t requested)
{
struct dhcp_packet packet;
*/
init_packet(&packet, DHCPDECLINE);
+#if 0
/* 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;
+#endif
/* 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 release...");
- return udhcp_send_kernel_packet(&packet, ciaddr, CLIENT_PORT, server, SERVER_PORT);
+ /* 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 */
int bytes;
struct ip_udp_dhcp_packet packet;
uint16_t check;
+ unsigned char cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
+ struct iovec iov;
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
- memset(&packet, 0, sizeof(packet));
- bytes = safe_read(fd, &packet, sizeof(packet));
- if (bytes < 0) {
- log1("Packet read error, ignoring");
- /* NB: possible down interface, etc. Caller should pause. */
- return bytes; /* returns -1 */
+ /* used to use just safe_read(fd, &packet, sizeof(packet))
+ * but we need to check for TP_STATUS_CSUMNOTREADY :(
+ */
+ iov.iov_base = &packet;
+ iov.iov_len = sizeof(packet);
+ memset(&msg, 0, sizeof(msg));
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ msg.msg_control = cmsgbuf;
+ msg.msg_controllen = sizeof(cmsgbuf);
+ for (;;) {
+ bytes = recvmsg(fd, &msg, 0);
+ if (bytes < 0) {
+ if (errno == EINTR)
+ continue;
+ log1("Packet read error, ignoring");
+ /* NB: possible down interface, etc. Caller should pause. */
+ return bytes; /* returns -1 */
+ }
+ break;
}
if (bytes < (int) (sizeof(packet.ip) + sizeof(packet.udp))) {
return -2;
}
+ for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+ if (cmsg->cmsg_level == SOL_PACKET
+ && cmsg->cmsg_type == PACKET_AUXDATA
+ ) {
+ /* some VMs don't checksum UDP and TCP data
+ * they send to the same physical machine,
+ * here we detect this case:
+ */
+ struct tpacket_auxdata *aux = (void *)CMSG_DATA(cmsg);
+ if (aux->tp_status & TP_STATUS_CSUMNOTREADY)
+ goto skip_udp_sum_check;
+ }
+ }
+
/* verify UDP checksum. IP header has to be modified for this */
memset(&packet.ip, 0, offsetof(struct iphdr, protocol));
/* ip.xx fields which are not memset: protocol, check, saddr, daddr */
log1("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");
return -2;
}
- log1("Got valid DHCP packet");
+ log1("Received a packet");
udhcp_dump_packet(&packet.data);
bytes -= sizeof(packet.ip) + sizeof(packet.udp);
log1("Opening raw socket on ifindex %d", ifindex); //log2?
fd = xsocket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP));
- log1("Got raw socket fd %d", fd); //log2?
+ log1("Got raw socket fd"); //log2?
sock.sll_family = AF_PACKET;
sock.sll_protocol = htons(ETH_P_IP);
/* 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 %d", fd); // log?
+ log1("Attached filter to raw socket fd"); // log?
+ }
+
+ if (setsockopt(fd, SOL_PACKET, PACKET_AUXDATA,
+ &const_int_1, sizeof(int)) < 0
+ ) {
+ if (errno != ENOPROTOOPT)
+ log1("Can't set PACKET_AUXDATA on raw socket");
}
log1("Created raw socket");
}
}
-static void perform_release(uint32_t requested_ip, uint32_t server_addr)
+static void perform_release(uint32_t server_addr, uint32_t requested_ip)
{
char buffer[sizeof("255.255.255.255")];
struct in_addr temp_addr;
//usage:# define IF_UDHCP_VERBOSE(...)
//usage:#endif
//usage:#define udhcpc_trivial_usage
-//usage: "[-fbnq"IF_UDHCP_VERBOSE("v")"oCRB] [-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: "[-fbq"IF_UDHCP_VERBOSE("v")IF_FEATURE_UDHCPC_ARPING("a")"RB] [-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: IF_FEATURE_UDHCP_PORT(
+//usage: "\n -P,--client-port PORT Use PORT (default 68)"
+//usage: )
//usage: "\n -s,--script PROG Run PROG at DHCP events (default "CONFIG_UDHCPC_DEFAULT_SCRIPT")"
+//usage: "\n -p,--pidfile FILE Create pidfile"
//usage: "\n -B,--broadcast Request broadcast replies"
-//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 -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 if lease is not obtained (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 -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 -o,--no-default-options Don't request any options (unless -O is given)"
+//usage: "\n -O,--request-option 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 -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: )
//usage: IF_NOT_LONG_OPTS(
//usage: "\n -i IFACE Interface to use (default eth0)"
-//usage: "\n -p FILE Create pidfile"
+//usage: IF_FEATURE_UDHCP_PORT(
+//usage: "\n -P PORT Use PORT (default 68)"
+//usage: )
//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"
-//usage: "\n -T N Pause between packets (default 3 seconds)"
-//usage: "\n -A N Wait N seconds (default 20) after failure"
+//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 if lease is not obtained (default 20)"
+//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 -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 -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 -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: )
//usage: )
//usage: "\nSignals:"
-//usage: "\n USR1 Renew current lease"
-//usage: "\n USR2 Release current lease"
+//usage: "\n USR1 Renew lease"
+//usage: "\n USR2 Release lease"
int udhcpc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int discover_retries = 3;
uint32_t server_addr = server_addr; /* for compiler */
uint32_t requested_ip = 0;
- uint32_t xid = 0;
- uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
+ uint32_t xid = xid; /* for compiler */
int packet_num;
int timeout; /* must be signed */
unsigned already_waited_sec;
unsigned opt;
int max_fd;
int retval;
- struct timeval tv;
- struct dhcp_packet packet;
fd_set rfds;
/* Default options */
, &list_x
IF_FEATURE_UDHCP_PORT(, &str_P)
IF_UDHCP_VERBOSE(, &dhcp_verbose)
- );
- if (opt & (OPT_h|OPT_H))
+ );
+ 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);
+ }
if (opt & OPT_F) {
/* FQDN option format: [0x51][len][flags][0][0]<fqdn> */
client_config.fqdn = alloc_dhcp_option(DHCP_FQDN, str_F, 3);
SERVER_PORT = CLIENT_PORT - 1;
}
#endif
- if (opt & OPT_o)
- client_config.no_default_options = 1;
while (list_O) {
char *optstr = llist_pop(&list_O);
unsigned n = bb_strtou(optstr, NULL, 0);
}
client_config.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);
+ }
+ }
+ }
while (list_x) {
char *optstr = llist_pop(&list_x);
char *colon = strchr(optstr, ':');
clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
memcpy(clientid_mac_ptr, client_config.client_mac, 6);
}
- if (str_V[0] != '\0')
+ if (str_V[0] != '\0') {
+ // can drop -V, str_V, client_config.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);
+ }
+
#if !BB_MMU
/* on NOMMU reexec (i.e., background) early */
if (!(opt & OPT_f)) {
* "continue" statements in code below jump to the top of the loop.
*/
for (;;) {
+ struct timeval tv;
+ struct dhcp_packet packet;
/* silence "uninitialized!" warning */
unsigned timestamp_before_wait = timestamp_before_wait;
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);
timestamp_before_wait = (unsigned)monotonic_sec();
- log1("Waiting on select...");
retval = select(max_fd + 1, &rfds, NULL, NULL, &tv);
if (retval < 0) {
/* EINTR? A signal was caught, don't panic */
NULL,
client_config.client_mac)
) {
- return 1; /* iface is gone? */
+ goto ret0; /* iface is gone? */
}
if (clientid_mac_ptr)
memcpy(clientid_mac_ptr, client_config.client_mac, 6);
switch (state) {
case INIT_SELECTING:
- if (packet_num < discover_retries) {
+ if (!discover_retries || packet_num < discover_retries) {
if (packet_num == 0)
xid = random_xid();
/* broadcast */
packet_num = 0;
continue;
case REQUESTING:
- if (packet_num < discover_retries) {
+ if (!discover_retries || packet_num < discover_retries) {
/* send broadcast select packet */
send_select(xid, server_addr, requested_ip);
timeout = discover_timeout;
timeout = 0;
continue;
case SIGUSR2:
- perform_release(requested_ip, server_addr);
+ perform_release(server_addr, requested_ip);
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;
}
switch (state) {
case INIT_SELECTING:
- /* Must be a DHCPOFFER to one of our xid's */
+ /* Must be a DHCPOFFER */
if (*message == DHCPOFFER) {
- /* TODO: why we don't just fetch server's IP from IP header? */
+/* What exactly is server's IP? There are several values.
+ * Example DHCP offer captured with tchdump:
+ *
+ * 10.34.25.254:67 > 10.34.25.202:68 // IP header's src
+ * BOOTP fields:
+ * Your-IP 10.34.25.202
+ * Server-IP 10.34.32.125 // "next server" IP
+ * Gateway-IP 10.34.25.254 // relay's address (if DHCP relays are in use)
+ * DHCP options:
+ * DHCP-Message Option 53, length 1: Offer
+ * Server-ID Option 54, length 4: 10.34.255.7 // "server ID"
+ * Default-Gateway Option 3, length 4: 10.34.25.254 // router
+ *
+ * We think that real server IP (one to use in renew/release)
+ * is one in Server-ID option. But I am not 100% sure.
+ * IP header's src and Gateway-IP (same in this example)
+ * might work too.
+ * "Next server" and router are definitely wrong ones to use, though...
+ */
+/* We used to ignore pcakets 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_option(&packet, DHCP_SERVER_ID);
if (!temp) {
- bb_error_msg("no server ID, ignoring packet");
- continue;
- /* still selecting - this server looks bad */
+ bb_error_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;
case RENEW_REQUESTED:
case REBINDING:
if (*message == DHCPACK) {
+ uint32_t lease_seconds;
+ struct in_addr temp_addr;
+
temp = udhcp_get_option(&packet, DHCP_LEASE_TIME);
if (!temp) {
bb_error_msg("no lease time with ACK, using 1 hour lease");
/* 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;
+ /* 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;
}
#if ENABLE_FEATURE_UDHCPC_ARPING
if (opt & OPT_a) {
) {
bb_info_msg("Offered address is in use "
"(got ARP reply), declining");
- send_decline(xid, server_addr, packet.yiaddr);
+ send_decline(/*xid,*/ server_addr, packet.yiaddr);
if (state != REQUESTING)
udhcp_run_script(NULL, "deconfig");
#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);
- }
+ 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 == REQUESTING ? "bound" : "renew");
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;
}
/* future renew failures should not exit (JM) */
opt = ((opt & ~OPT_b) | OPT_f);
}
#endif
+ /* make future renew packets use different xid */
+ /* xid = random_xid(); ...but why bother? */
already_waited_sec = 0;
continue; /* back to main loop */
}
} /* for (;;) - main loop ends */
ret0:
+ if (opt & OPT_R) /* release on quit */
+ perform_release(server_addr, requested_ip);
retval = 0;
ret:
/*if (client_config.pidfile) - remove_pidfile has its own check */
projects / oweals / busybox.git / blobdiff