udhcpc: add -x OPT:VAL option

function                                             old     new   delta
udhcp_str2optset                                       -     443    +443
add_client_options                                     -     160    +160
udhcpc_main                                         2753    2857    +104
packed_usage                                       26670   26689     +19
attach_option                                        380     385      +5
udhcpd_main                                         1964    1965      +1
udhcp_add_option_string                               94      86      -8
add_param_req_option                                 128       -    -128
read_opt                                             443       -    -443
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 4/1 up/down: 732/-579)          Total: 153 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

7 files changed, 61 insertions, 24 deletions

diff --git a/include/usage.h b/include/usage.h
index 40cb6b2..a343b41 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -4821,6 +4821,7 @@
      "\n	-t,--retries N		Send up to N discover packets" \
      "\n	-T,--timeout N		Pause between packets (default 3 seconds)" \
      "\n	-A,--tryagain N		Wait N seconds (default 20) after failure" \
+     "\n	-x OPT:VAL		Include option OPT in sent packets (cumulative)" \
      "\n	-O,--request-option OPT	Request DHCP option OPT (cumulative)" \
      "\n	-o,--no-default-options	Don't request any options (unless -O is given)" \
      "\n	-f,--foreground		Run in foreground" \
@@ -4851,6 +4852,7 @@
      "\n	-t N		Send up to N discover packets" \
      "\n	-T N		Pause between packets (default 3 seconds)" \
      "\n	-A N		Wait N seconds (default 20) after failure" \
+     "\n	-x OPT:VAL	Include option OPT in sent packets" \
      "\n	-O OPT		Request DHCP option OPT (cumulative)" \
      "\n	-o		Don't request any options (unless -O is given)" \
      "\n	-f		Run in foreground" \
diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index 15fe785..9c3b496 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -161,6 +161,11 @@ struct dhcp_option {
 	uint8_t code;
 };
 
+struct option_set {
+	uint8_t *data;
+	struct option_set *next;
+};
+
 extern const struct dhcp_option dhcp_options[];
 extern const char dhcp_option_strings[];
 extern const uint8_t dhcp_option_lengths[];
@@ -173,6 +178,9 @@ void udhcp_add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data) FA
 char *dname_dec(const uint8_t *cstr, int clen, const char *pre) FAST_FUNC;
 uint8_t *dname_enc(const uint8_t *cstr, int clen, const char *src, int *retlen) FAST_FUNC;
 #endif
+/* 2nd param is actually "struct option_set**" */
+int FAST_FUNC udhcp_str2optset(const char *const_line, void *arg);
+
 
 // RFC 2131  Table 5: Fields and options used by DHCP clients
 //
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 7587509..4565d7f 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -331,11 +331,11 @@ static void init_packet(struct dhcp_packet *packet, char type)
 	}
 }
 
-/* Add a parameter request list for stubborn DHCP servers. Pull the data
- * from the struct in options.c. Don't do bounds checking here because it
- * goes towards the head of the packet. */
-static void add_param_req_option(struct dhcp_packet *packet)
+static void add_client_options(struct dhcp_packet *packet)
 {
+	/* Add am "param req" option with the list of options we'd like to have
+	 * from stubborn DHCP servers. Pull the data from the struct in options.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;
@@ -355,6 +355,19 @@ static void add_param_req_option(struct dhcp_packet *packet)
 		packet->options[end + OPT_LEN] = len;
 		packet->options[end + OPT_DATA + len] = DHCP_END;
 	}
+
+	/* Add -x options if any */
+	{
+		struct option_set *curr = client_config.options;
+		while (curr) {
+			udhcp_add_option_string(packet->options, 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);
+	}
 }
 
 /* RFC 2131
@@ -395,7 +408,7 @@ static int send_discover(uint32_t xid, uint32_t requested)
 	/* Explicitly saying that we want RFC-compliant packets helps
 	 * some buggy DHCP servers to NOT send bigger packets */
 	udhcp_add_simple_option(packet.options, DHCP_MAX_SIZE, htons(576));
-	add_param_req_option(&packet);
+	add_client_options(&packet);
 
 	bb_info_msg("Sending discover...");
 	return raw_bcast_from_client_config_ifindex(&packet);
@@ -414,7 +427,7 @@ static int send_select(uint32_t xid, uint32_t server, uint32_t requested)
 	packet.xid = xid;
 	udhcp_add_simple_option(packet.options, DHCP_REQUESTED_IP, requested);
 	udhcp_add_simple_option(packet.options, DHCP_SERVER_ID, server);
-	add_param_req_option(&packet);
+	add_client_options(&packet);
 
 	addr.s_addr = requested;
 	bb_info_msg("Sending select for %s...", inet_ntoa(addr));
@@ -429,7 +442,7 @@ static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
 	init_packet(&packet, DHCPREQUEST);
 	packet.xid = xid;
 	packet.ciaddr = ciaddr;
-	add_param_req_option(&packet);
+	add_client_options(&packet);
 
 	bb_info_msg("Sending renew...");
 	if (server)
@@ -728,6 +741,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 	const char *str_c, *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;
 	int tryagain_timeout = 20;
 	int discover_timeout = 3;
 	int discover_retries = 3;
@@ -792,9 +806,10 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 		OPT_A = 1 << 16,
 		OPT_O = 1 << 17,
 		OPT_o = 1 << 18,
-		OPT_f = 1 << 19,
+		OPT_x = 1 << 19,
+		OPT_f = 1 << 20,
 /* The rest has variable bit positions, need to be clever */
-		OPTBIT_f = 19,
+		OPTBIT_f = 20,
 		USE_FOR_MMU(             OPTBIT_b,)
 		IF_FEATURE_UDHCPC_ARPING(OPTBIT_a,)
 		IF_FEATURE_UDHCP_PORT(   OPTBIT_P,)
@@ -811,14 +826,14 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 	str_V = "udhcp "BB_VER;
 
 	/* Parse command line */
-	/* Cc: mutually exclusive; O: list; -T,-t,-A take numeric param */
-	opt_complementary = "c--C:C--c:O::T+:t+:A+"
+	/* Cc: mutually exclusive; O,x: list; -T,-t,-A take numeric param */
+	opt_complementary = "c--C:C--c: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:of"
+	opt = getopt32(argv, "c: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:")
@@ -828,6 +843,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 		, &client_config.script /* s */
 		, &discover_timeout, &discover_retries, &tryagain_timeout /* T,t,A */
 		, &list_O
+		, &list_x
 		IF_FEATURE_UDHCP_PORT(, &str_P)
 #if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 1
 		, &dhcp_verbose
@@ -868,6 +884,19 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 		n = dhcp_options[n].code;
 		client_config.opt_mask[n >> 3] |= 1 << (n & 7);
 	}
+	while (list_x) {
+		int n;
+		char *optstr = llist_pop(&list_x);
+		char *colon = strchr(optstr, ':');
+		if (colon)
+			*colon = '\0';
+		n = index_in_strings(dhcp_option_strings, optstr);
+		if (n < 0)
+			bb_error_msg_and_die("unknown option '%s'", optstr);
+		if (colon)
+			*colon = ' ';
+		udhcp_str2optset(optstr, &client_config.options);
+	}
 
 	if (udhcp_read_interface(client_config.interface,
 			&client_config.ifindex,
diff --git a/networking/udhcp/dhcpc.h b/networking/udhcp/dhcpc.h
index 4c17353..fba747f 100644
--- a/networking/udhcp/dhcpc.h
+++ b/networking/udhcp/dhcpc.h
@@ -13,6 +13,7 @@ struct client_config_t {
 	const char *interface;          /* The name of the interface to use */
 	char *pidfile;                  /* Optionally store the process ID */
 	const char *script;             /* User script to run at dhcp events */
+	struct option_set *options;     /* list of DHCP options to send to server */
 	uint8_t *clientid;              /* Optional client id to use */
 	uint8_t *vendorclass;           /* Optional vendor class-id to use */
 	uint8_t *hostname;              /* Optional hostname to use */
diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index b163ce7..a4e9a58 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -13,11 +13,6 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
 #define DHCPD_CONF_FILE         "/etc/udhcpd.conf"
 
 
-struct option_set {
-	uint8_t *data;
-	struct option_set *next;
-};
-
 struct static_lease {
 	struct static_lease *next;
 	uint32_t nip;
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 05a7b99..fddda4c 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -145,7 +145,7 @@ static NOINLINE void attach_option(
 }
 
 /* read a dhcp option and add it to opt_list */
-static int FAST_FUNC read_opt(const char *const_line, void *arg)
+int FAST_FUNC udhcp_str2optset(const char *const_line, void *arg)
 {
 	struct option_set **opt_list = arg;
 	char *opt, *val, *endptr;
@@ -292,8 +292,8 @@ static const struct config_keyword keywords[] = {
 	{"pidfile",      read_str, &(server_config.pidfile),      "/var/run/udhcpd.pid"},
 	{"siaddr",       read_nip, &(server_config.siaddr_nip),   "0.0.0.0"},
 	/* keywords with no defaults must be last! */
-	{"option",       read_opt, &(server_config.options),      ""},
-	{"opt",          read_opt, &(server_config.options),      ""},
+	{"option",       udhcp_str2optset, &(server_config.options), ""},
+	{"opt",          udhcp_str2optset, &(server_config.options), ""},
 	{"notify_file",  read_str, &(server_config.notify_file),  ""},
 	{"sname",        read_str, &(server_config.sname),        ""},
 	{"boot_file",    read_str, &(server_config.boot_file),    ""},
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index b4d2d2d..af3c217 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -212,7 +212,7 @@ int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 
 	while (optionptr[i] != DHCP_END) {
 		if (optionptr[i] != DHCP_PADDING)
-			i += optionptr[i + OPT_LEN] + 1;
+			i += optionptr[i + OPT_LEN] + OPT_DATA-1;
 		i++;
 	}
 	return i;
@@ -222,7 +222,8 @@ int FAST_FUNC udhcp_end_option(uint8_t *optionptr)
 /* option bytes: [code][len][data1][data2]..[dataLEN] */
 void FAST_FUNC udhcp_add_option_string(uint8_t *optionptr, uint8_t *string)
 {
-	int end = udhcp_end_option(optionptr);
+	unsigned len;
+	unsigned end = udhcp_end_option(optionptr);
 
 	/* end position + string length + option code/length + end option */
 	if (end + string[OPT_LEN] + 2 + 1 >= DHCP_OPTIONS_BUFSIZE) {
@@ -231,8 +232,9 @@ void FAST_FUNC udhcp_add_option_string(uint8_t *optionptr, uint8_t *string)
 		return;
 	}
 	log_option("Adding option", string);
-	memcpy(optionptr + end, string, string[OPT_LEN] + 2);
-	optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
+	len = OPT_DATA + string[OPT_LEN];
+	memcpy(optionptr + end, string, len);
+	optionptr[end + len] = DHCP_END;
 }
 
 /* add a one to four byte option to a packet */