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 40cb6b2bb..a343b41da 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 15fe785c1..9c3b4960b 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 758750907..4565d7fd2 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 4c173533c..fba747f0c 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 b163ce7eb..a4e9a58ff 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 05a7b998a..fddda4cba 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 b4d2d2de3..af3c217e8 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 */