1 files changed, 235 insertions, 59 deletions

diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 27d6ad1a8..78aabedf2 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -346,31 +346,28 @@ static ALWAYS_INLINE uint32_t random_xid(void)
 /* 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);
-        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
-        ) {
-                udhcp_add_binary_option(packet, client_config.vendorclass);
-        }
 }
 
 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));
+
         /* 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
@@ -387,6 +384,13 @@ static void add_client_options(struct dhcp_packet *packet)
                 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);
+
         /* Add -x options if any */
         {
                 struct option_set *curr = client_config.options;
@@ -428,17 +432,25 @@ static int raw_bcast_from_client_config_ifindex(struct dhcp_packet *packet)
 }
 
 /* Broadcast a DHCP discover packet to the network, with an optionally requested IP */
-static int send_discover(uint32_t xid, uint32_t requested)
+/* NOINLINE: limit stack usage in caller */
+static NOINLINE int send_discover(uint32_t xid, uint32_t requested)
 {
         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...");
@@ -449,15 +461,39 @@ static int send_discover(uint32_t xid, uint32_t requested)
 /* RFC 2131 3.1 paragraph 3:
  * "The client _broadcasts_ a DHCPREQUEST message..."
  */
-static int send_select(uint32_t xid, uint32_t server, uint32_t requested)
+/* NOINLINE: limit stack usage in caller */
+static NOINLINE int send_select(uint32_t xid, uint32_t server, uint32_t requested)
 {
         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;
@@ -466,13 +502,38 @@ static int send_select(uint32_t xid, uint32_t server, uint32_t requested)
 }
 
 /* Unicast or broadcast a DHCP renew message */
-static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
+/* NOINLINE: limit stack usage in caller */
+static NOINLINE int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
 {
         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...");
@@ -485,13 +546,25 @@ static int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr)
 
 #if ENABLE_FEATURE_UDHCPC_ARPING
 /* Broadcast a DHCP decline message */
-static int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
+/* NOINLINE: limit stack usage in caller */
+static NOINLINE int send_decline(uint32_t xid, uint32_t server, uint32_t requested)
 {
         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...");
@@ -504,8 +577,12 @@ static int send_release(uint32_t server, uint32_t ciaddr)
 {
         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);
@@ -515,6 +592,7 @@ static int send_release(uint32_t server, uint32_t ciaddr)
 }
 
 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
+/* NOINLINE: limit stack usage in caller */
 static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd)
 {
         int bytes;
@@ -765,12 +843,97 @@ static void client_background(void)
 }
 #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;)
+        void *clientid_mac_ptr;
         llist_t *list_O = NULL;
         llist_t *list_x = NULL;
         int tryagain_timeout = 20;
@@ -792,7 +955,6 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 
 #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"
@@ -818,29 +980,28 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 ;
 #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,)
@@ -849,7 +1010,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 IF_FEATURE_UDHCP_PORT(   OPT_P = 1 << OPTBIT_P,)
         };
 
-        /* Default options. */
+        /* Default options */
         IF_FEATURE_UDHCP_PORT(SERVER_PORT = 67;)
         IF_FEATURE_UDHCP_PORT(CLIENT_PORT = 68;)
         client_config.interface = "eth0";
@@ -857,19 +1018,19 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
         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 */
@@ -931,13 +1092,13 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 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 */
+        clientid_mac_ptr = NULL;
+        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);
+                clientid_mac_ptr = client_config.clientid + OPT_DATA+1;
+                memcpy(clientid_mac_ptr, client_config.client_mac, 6);
         }
         if (str_V[0] != '\0')
                 client_config.vendorclass = alloc_dhcp_option(DHCP_VENDOR, str_V, 0);
@@ -1015,6 +1176,21 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                  * 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:
+                         */
+                        if (udhcp_read_interface(client_config.interface,
+                                        &client_config.ifindex,
+                                        NULL,
+                                        client_config.client_mac)
+                        ) {
+                                return 1; /* iface is gone? */
+                        }
+                        if (clientid_mac_ptr)
+                                memcpy(clientid_mac_ptr, client_config.client_mac, 6);
+
                         /* We will restart the wait in any case */
                         already_waited_sec = 0;
 
@@ -1174,7 +1350,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
 
                 /* 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?
@@ -1194,13 +1370,13 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv)
                 /* TODO: why we don't just fetch server's IP from IP header? */
                                 temp = udhcp_get_option(&packet, DHCP_SERVER_ID);
                                 if (!temp) {
-                                        bb_error_msg("no server ID in message");
+                                        bb_error_msg("no server ID, ignoring packet");
                                         continue;
                                         /* still selecting - this server looks bad */
                                 }
                                 /* 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 */