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223bc97f6

Denis Vlasenko

2007-11-22

FAILED Duration: 19s

Subject

udhcpc: an option to perform ARP check (Jonas Danielsson ) configurable, ~+300 bytes when on.

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

include/usage.h +27 -21 networking/udhcp/Config.in +10 -0 networking/udhcp/Kbuild +6 -0 networking/udhcp/arpping.c +20 -9 networking/udhcp/clientpacket.c +16 -0 networking/udhcp/common.h +1 -1 networking/udhcp/dhcpc.c +53 -12 networking/udhcp/dhcpc.h +4 -3 networking/udhcp/signalpipe.c +1 -1

include/usage.h+27 -21

@@ -2183,8 +2183,8 @@
	"and * (run both after creating and before deleting). The commands run in\n" \
	"the /dev directory, and use system() which calls /bin/sh.\n\n" \
	) \
-	"Config file parsing stops on the first matching line. If no config\n"\
-	"entry is matched, devices are created with default 0:0 660. (Make\n"\
+	"Config file parsing stops on the first matching line. If no config\n" \
+	"entry is matched, devices are created with default 0:0 660. (Make\n" \
	"the last line match .* to override this.)\n\n" \
	)

@@ -3843,44 +3843,50 @@ USE_FEATURE_RUN_PARTS_FANCY("\n -l Prints names of all matching files even when
	" [-p pidfile] [-r IP] [-s script]"
	#define udhcpc_full_usage \
	USE_GETOPT_LONG( \
-	" -V,--vendorclass=CLASSID Set vendor class identifier" \
-	"\n -i,--interface=INTERFACE Interface to use (default: eth0)" \
+	" -V,--vendorclass=CLASSID Vendor class identifier" \
+	"\n -i,--interface=INTERFACE Interface to use (default eth0)" \
	"\n -H,-h,--hostname=HOSTNAME Client hostname" \
-	"\n -c,--clientid=CLIENTID Set client identifier" \
+	"\n -c,--clientid=CLIENTID Client identifier" \
	"\n -C,--clientid-none Suppress default client identifier" \
-	"\n -p,--pidfile=file Store process ID of daemon in file" \
+	"\n -p,--pidfile=file Create pidfile" \
	"\n -r,--request=IP IP address to request" \
	"\n -s,--script=file Run file at dhcp events (default: /usr/share/udhcpc/default.script)" \
-	"\n -t,--retries=N Send up to N request packets"\
-	"\n -T,--timeout=N Try to get a lease for N seconds (default: 3)"\
-	"\n -A,--tryagain=N Wait N seconds (default: 60) after failure"\
+	"\n -t,--retries=N Send up to N request packets" \
+	"\n -T,--timeout=N Try to get a lease for N seconds (default 3)" \
+	"\n -A,--tryagain=N Wait N seconds (default 60) after failure" \
	"\n -f,--foreground Run in foreground" \
-	"\n -b,--background Background if lease cannot be immediately negotiated" \
+	"\n -b,--background Background if lease is not immediately obtained" \
	"\n -S,--syslog Log to syslog too" \
-	"\n -n,--now Exit with failure if lease cannot be immediately negotiated" \
+	"\n -n,--now Exit with failure if lease is not immediately obtained" \
	"\n -q,--quit Quit after obtaining lease" \
	"\n -R,--release Release IP on quit" \
-	"\n -v,--version Display version" \
+	USE_FEATURE_UDHCPC_ARPING( \
+	"\n -a,--arping Use arping to validate offered address" \
+	"\n -W,--wait=N Wait N seconds after declining (default 10)" \
+	) \
	) \
	SKIP_GETOPT_LONG( \
-	" -V CLASSID Set vendor class identifier" \
+	" -V CLASSID Vendor class identifier" \
	"\n -i INTERFACE Interface to use (default: eth0)" \
	"\n -H,-h HOSTNAME Client hostname" \
-	"\n -c CLIENTID Set client identifier" \
+	"\n -c CLIENTID Client identifier" \
	"\n -C Suppress default client identifier" \
-	"\n -p file Store process ID of daemon in file" \
+	"\n -p file Create pidfile" \
	"\n -r IP IP address to request" \
	"\n -s file Run file at dhcp events (default: /usr/share/udhcpc/default.script)" \
-	"\n -t N Send up to N request packets"\
-	"\n -T N Try to get a lease for N seconds (default: 3)"\
-	"\n -A N Wait N seconds (default: 60) after failure"\
+	"\n -t N Send up to N request packets" \
+	"\n -T N Try to get a lease for N seconds (default 3)" \
+	"\n -A N Wait N seconds (default 60) after failure" \
	"\n -f Run in foreground" \
-	"\n -b Background if lease cannot be immediately negotiated" \
+	"\n -b Background if lease is not immediately obtained" \
	"\n -S Log to syslog too" \
-	"\n -n Exit with failure if lease cannot be immediately negotiated" \
+	"\n -n Exit with failure if lease is not immediately obtained" \
	"\n -q Quit after obtaining lease" \
	"\n -R Release IP on quit" \
-	"\n -v Display version" \
+	USE_FEATURE_UDHCPC_ARPING( \
+	"\n -a Use arping to validate offered address" \
+	"\n -W N Wait N seconds after declining (default 10)" \
+	) \
	)

	#define udhcpd_trivial_usage \

networking/udhcp/Config.in+10 -0

@@ -54,6 +54,16 @@ config APP_UDHCPC

	See http://udhcp.busybox.net for further details.

+	config FEATURE_UDHCPC_ARPING
+	bool "Ask udhcpc to verify that the offered address is free, using arpping"
+	default y
+	depends on APP_UDHCPC
+	help
+	If selected, udhcpc will use arpping to make sure the offered address
+	is really available. The client will DHCPDECLINE the offer if the
+	address is in use, and restart the discover process.
+
+
	config FEATURE_UDHCP_DEBUG
	bool "Compile udhcp with noisy debugging messages"
	default n

networking/udhcp/Kbuild+6 -0

@@ -10,10 +10,16 @@ lib-$(CONFIG_APP_UDHCPC) += common.o options.o packet.o \
	signalpipe.o socket.o
	lib-$(CONFIG_APP_UDHCPD) += common.o options.o packet.o \
	signalpipe.o socket.o
+
	lib-$(CONFIG_APP_UDHCPC) += dhcpc.o clientpacket.o clientsocket.o \
	script.o
+
+	UDHCPC_NEEDS_ARPING-$(CONFIG_FEATURE_UDHCPC_ARPING) = y
+	lib-$(UDHCPC_NEEDS_ARPING) += arpping.o
+
	lib-$(CONFIG_APP_UDHCPD) += dhcpd.o arpping.o files.o leases.o \
	serverpacket.o static_leases.o
+
	lib-$(CONFIG_APP_DUMPLEASES) += dumpleases.o
	lib-$(CONFIG_APP_DHCPRELAY) += dhcprelay.o
	lib-$(CONFIG_FEATURE_RFC3397) += domain_codec.o

networking/udhcp/arpping.c+20 -9

@@ -32,12 +32,16 @@ struct arpMsg {
	uint8_t pad[18]; /* 2a pad for min. ethernet payload (60 bytes) */
	} ATTRIBUTE_PACKED;

+	enum {
+	ARP_MSG_SIZE = 0x2a
+	};
+

	/* Returns 1 if no reply received */

	int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t from_mac, const char interface)
	{
-	int timeout_ms = 2000;
+	int timeout_ms;
	struct pollfd pfd[1];
	#define s (pfd[0].fd) /* socket */
	int rv = 1; /* "no reply received" yet */
@@ -51,7 +55,7 @@ int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t from_mac, const char i
	}

	if (setsockopt_broadcast(s) == -1) {
-	bb_perror_msg("cannot setsocketopt on raw socket");
+	bb_perror_msg("cannot enable bcast on raw socket");
	goto ret;
	}

@@ -67,28 +71,35 @@ int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t from_mac, const char i
	arp.operation = htons(ARPOP_REQUEST); /* ARP op code */
	memcpy(arp.sHaddr, from_mac, 6); /* source hardware address */
	memcpy(arp.sInaddr, &from_ip, sizeof(from_ip)); /* source IP address */
-	/* tHaddr / / target hardware address */
+	/* tHaddr is zero-fiiled / / target hardware address */
	memcpy(arp.tInaddr, &test_ip, sizeof(test_ip)); /* target IP address */

	memset(&addr, 0, sizeof(addr));
	safe_strncpy(addr.sa_data, interface, sizeof(addr.sa_data));
-	if (sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0)
+	if (sendto(s, &arp, sizeof(arp), 0, &addr, sizeof(addr)) < 0) {
+	// TODO: error message? caller didn't expect us to fail,
+	// just returning 1 "no reply received" misleads it.
	goto ret;
+	}

	/* wait for arp reply, and check it */
+	timeout_ms = 2000;
	do {
	int r;
	unsigned prevTime = monotonic_us();

	pfd[0].events = POLLIN;
	r = safe_poll(pfd, 1, timeout_ms);
-	if (r < 0) {
+	if (r < 0)
	break;
-	} else if (r) {
-	if (read(s, &arp, sizeof(arp)) < 0)
+	if (r) {
+	r = read(s, &arp, sizeof(arp));
+	if (r < 0)
	break;
-	if (arp.operation == htons(ARPOP_REPLY)
-	&& memcmp(arp.tHaddr, from_mac, 6) == 0
+	if (r >= ARP_MSG_SIZE
+	&& arp.operation == htons(ARPOP_REPLY)
+	/* don't check it: Linux doesn't return proper tHaddr (fixed in 2.6.24?) */
+	/* && memcmp(arp.tHaddr, from_mac, 6) == 0 */
	&& ((uint32_t ) arp.sInaddr) == test_ip
	) {
	rv = 0;

networking/udhcp/clientpacket.c+16 -0

@@ -69,6 +69,22 @@ static void add_requests(struct dhcpMessage *packet)

	}

+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	/* Unicast a DHCP decline message */
+	int send_decline(uint32_t xid, uint32_t server)
+	{
+	struct dhcpMessage packet;
+
+	init_packet(&packet, DHCPDECLINE);
+	packet.xid = xid;
+	add_requests(&packet);
+
+	bb_info_msg("Sending decline...");
+
+	return udhcp_raw_packet(&packet, INADDR_ANY, CLIENT_PORT, INADDR_BROADCAST,
+	SERVER_PORT, MAC_BCAST_ADDR, client_config.ifindex);
+	}
+	#endif

	/* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
	int send_discover(uint32_t xid, uint32_t requested)

networking/udhcp/common.h+1 -1

@@ -76,7 +76,7 @@ void udhcp_run_script(struct dhcpMessage packet, const char name);

	void udhcp_sp_setup(void);
	int udhcp_sp_fd_set(fd_set *rfds, int extra_fd);
-	int udhcp_sp_read(fd_set *rfds);
+	int udhcp_sp_read(const fd_set *rfds);
	int raw_socket(int ifindex);
	int read_interface(const char interface, int ifindex, uint32_t addr, uint8_t arp);
	int listen_socket(/uint32_t ip,/ int port, const char *inf);

networking/udhcp/dhcpc.c+53 -12

@@ -145,6 +145,13 @@ int udhcpc_main(int argc, char **argv)
	{
	uint8_t temp, message;
	char str_c, str_V, str_h, str_F, str_r, str_T, str_A, str_t;
+	int tryagain_timeout = 60;
+	int discover_timeout = 3;
+	int discover_retries = 3;
+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	int decline_wait = 10;
+	char *str_W;
+	#endif
	uint32_t xid = 0;
	uint32_t lease = 0; /* can be given as 32-bit quantity */
	unsigned t1 = 0, t2 = 0; /* what a wonderful names */
@@ -180,6 +187,10 @@ int udhcpc_main(int argc, char **argv)
	OPT_v = 1 << 17,
	OPT_S = 1 << 18,
	OPT_A = 1 << 19,
+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	OPT_a = 1 << 20,
+	OPT_W = 1 << 21,
+	#endif
	};
	#if ENABLE_GETOPT_LONG
	static const char udhcpc_longopts[] ALIGN1 =
@@ -203,14 +214,15 @@ int udhcpc_main(int argc, char **argv)
	"retries\0" Required_argument "t"
	"tryagain\0" Required_argument "A"
	"syslog\0" No_argument "S"
+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	"arping\0" No_argument "a"
+	"wait\0" Required_argument "W"
+	#endif
	;
	#endif
	/* Default options. */
	client_config.interface = "eth0";
	client_config.script = DEFAULT_SCRIPT;
-	client_config.retries = 3;
-	client_config.timeout = 3;
-	client_config.tryagain = 60;

	/* Parse command line */
	opt_complementary = "c--C:C--c" // mutually exclusive
@@ -218,10 +230,12 @@ int udhcpc_main(int argc, char **argv)
	#if ENABLE_GETOPT_LONG
	applet_long_options = udhcpc_longopts;
	#endif
-	opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:",
-	&str_c, &str_V, &str_h, &str_h, &str_F,
+	opt = getopt32(argv, "c:CV:fbH:h:F:i:np:qRr:s:T:t:vSA:"
+	USE_FEATURE_UDHCPC_ARPING("aW:")
+	, &str_c, &str_V, &str_h, &str_h, &str_F,
	&client_config.interface, &client_config.pidfile, &str_r,
	&client_config.script, &str_T, &str_t, &str_A
+	USE_FEATURE_UDHCPC_ARPING(, &str_W)
	);

	if (opt & OPT_c)
@@ -259,11 +273,11 @@ int udhcpc_main(int argc, char **argv)
	requested_ip = inet_addr(str_r);
	// if (opt & OPT_s) client_config.script = ...
	if (opt & OPT_T)
-	client_config.timeout = xatoi_u(str_T);
+	discover_timeout = xatoi_u(str_T);
	if (opt & OPT_t)
-	client_config.retries = xatoi_u(str_t);
+	discover_retries = xatoi_u(str_t);
	if (opt & OPT_A)
-	client_config.tryagain = xatoi_u(str_A);
+	tryagain_timeout = xatoi_u(str_A);
	if (opt & OPT_v) {
	puts("version "BB_VER);
	return 0;
@@ -274,6 +288,11 @@ int udhcpc_main(int argc, char **argv)
	logmode \|= LOGMODE_SYSLOG;
	}

+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	if (opt & OPT_W)
+	decline_wait = xatou_range(str_W, 10, INT_MAX);
+	#endif
+
	if (read_interface(client_config.interface, &client_config.ifindex,
	NULL, client_config.arp))
	return 1;
@@ -339,14 +358,14 @@ int udhcpc_main(int argc, char **argv)
	/* timeout dropped to zero */
	switch (state) {
	case INIT_SELECTING:
-	if (packet_num < client_config.retries) {
+	if (packet_num < discover_retries) {
	if (packet_num == 0)
	xid = random_xid();

	/* send discover packet */
	send_discover(xid, requested_ip); /* broadcast */

-	timeout = now + client_config.timeout;
+	timeout = now + discover_timeout;
	packet_num++;
	} else {
	udhcp_run_script(NULL, "leasefail");
@@ -360,12 +379,12 @@ int udhcpc_main(int argc, char **argv)
	}
	/* wait to try again */
	packet_num = 0;
-	timeout = now + client_config.tryagain;
+	timeout = now + tryagain_timeout;
	}
	break;
	case RENEW_REQUESTED:
	case REQUESTING:
-	if (packet_num < client_config.retries) {
+	if (packet_num < discover_retries) {
	/* send request packet */
	if (state == RENEW_REQUESTED)
	send_renew(xid, server_addr, requested_ip); /* unicast */
@@ -491,6 +510,28 @@ int udhcpc_main(int argc, char **argv)
	lease = ntohl(lease);
	}

+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	if (opt & OPT_a) {
+	if (!arpping(packet.yiaddr,
+	(uint32_t) 0,
+	client_config.arp,
+	client_config.interface)
+	) {
+	bb_info_msg("offered address is in use,"
+	" declining");
+	send_decline(xid, server_addr);
+
+	if (state != REQUESTING)
+	udhcp_run_script(NULL, "deconfig");
+	state = INIT_SELECTING;
+	requested_ip = 0;
+	packet_num = 0;
+	change_mode(LISTEN_RAW);
+	timeout = now + decline_wait;
+	break;
+	}
+	}
+	#endif
	/* enter bound state */
	t1 = lease / 2;

networking/udhcp/dhcpc.h+4 -3

@@ -1,5 +1,6 @@
	/* vi: set sw=4 ts=4: */
	/* dhcpc.h */
+
	#ifndef _DHCPC_H
	#define _DHCPC_H

@@ -28,9 +29,6 @@ struct client_config_t {
	uint8_t hostname; / Optional hostname to use */
	uint8_t fqdn; / Optional fully qualified domain name to use */
	int ifindex; /* Index number of the interface to use */
-	int retries; /* Max number of request packets */
-	int timeout; /* Number of seconds to try to get a lease */
-	int tryagain; /* Number of seconds to try to get a lease */
	uint8_t arp[6]; /* Our arp address */
	};

@@ -42,6 +40,9 @@ struct client_config_t {
	uint32_t random_xid(void);
	int send_discover(uint32_t xid, uint32_t requested);
	int send_selecting(uint32_t xid, uint32_t server, uint32_t requested);
+	#if ENABLE_FEATURE_UDHCPC_ARPING
+	int send_decline(uint32_t xid, uint32_t server);
+	#endif
	int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr);
	int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr);
	int send_release(uint32_t server, uint32_t ciaddr);

networking/udhcp/signalpipe.c+1 -1

@@ -66,7 +66,7 @@ int udhcp_sp_fd_set(fd_set *rfds, int extra_fd)
	/* Read a signal from the signal pipe. Returns 0 if there is
	* no signal, -1 on error (and sets errno appropriately), and
	* your signal on success */
-	int udhcp_sp_read(fd_set *rfds)
+	int udhcp_sp_read(const fd_set *rfds)
	{
	unsigned char sig;