dhcp: heed TODO item - divorced options from their string descriptions

code shrink while at it.

function                                             old     new   delta
dhcp_option_strings                                    -     258    +258
udhcp_run_script                                    1135    1174     +39
dhcp_option_lengths                                    -      11     +11
udhcp_add_simple_option                               93      92      -1
packet_num                                             4       -      -4
read_opt                                             746     739      -7
udhcp_option_lengths                                  11       -     -11
udhcpc_main                                         2590    2494     -96
dhcp_options                                         490      70    -420
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 1/4 up/down: 308/-539)         Total: -231 bytes
   text    data     bss     dec     hex filename
 775309     929    9100  785338   bfbba busybox_old
 775098     929    9084  785111   bfad7 busybox_unstripped

8 files changed, 135 insertions, 88 deletions

diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h
index eecb72ca2..55782b51b 100644
--- a/networking/udhcp/common.h
+++ b/networking/udhcp/common.h
@@ -77,7 +77,6 @@ void udhcp_run_script(struct dhcpMessage *packet, const char *name);
 #define end_option              udhcp_end_option
 #define add_option_string       udhcp_add_option_string
 #define add_simple_option       udhcp_add_simple_option
-#define option_lengths          udhcp_option_lengths
 /* from socket.h */
 #define listen_socket           udhcp_listen_socket
 #define read_interface          udhcp_read_interface
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c
index 6ade1ee34..d8077f7e8 100644
--- a/networking/udhcp/dhcpc.c
+++ b/networking/udhcp/dhcpc.c
@@ -19,15 +19,9 @@
 #include "options.h"
 
 
-/* Something is definitely wrong here. IPv4 addresses
- * in variables of type long?? BTW, we use inet_ntoa()
- * in the code. Manpage says that struct in_addr has a member of type long (!)
- * which holds IPv4 address, and the struct is passed by value (!!)
- */
 static int timeout; /* = 0. Must be signed */
 static uint32_t requested_ip; /* = 0 */
 static uint32_t server_addr;
-static int packet_num; /* = 0 */
 static int sockfd = -1;
 
 #define LISTEN_NONE 0
@@ -74,12 +68,6 @@ static void perform_renew(void)
         case INIT_SELECTING:
                 break;
         }
-
-        /* start things over */
-        packet_num = 0;
-
-        /* Kill any timeouts because the user wants this to hurry along */
-        timeout = 0;
 }
 
 
@@ -153,8 +141,11 @@ int udhcpc_main(int argc, char **argv)
         int discover_retries = 3;
         uint32_t xid = 0;
         uint32_t lease_seconds = 0; /* can be given as 32-bit quantity */
-        unsigned t1 = 0, t2 = 0; /* what a wonderful names */
-        unsigned timestamp_got_lease = 0; /* for gcc */
+        int packet_num;
+        /* t1, t2... what a wonderful names... */
+        unsigned t1 = t1; /* for gcc */
+        unsigned t2 = t2;
+        unsigned timestamp_got_lease = timestamp_got_lease;
         unsigned opt;
         int max_fd;
         int retval;
@@ -315,6 +306,7 @@ int udhcpc_main(int argc, char **argv)
         state = INIT_SELECTING;
         udhcp_run_script(NULL, "deconfig");
         change_listen_mode(LISTEN_RAW);
+        packet_num = 0;
 
         /* Main event loop. select() waits on signal pipe and possibly
          * on sockfd.
@@ -585,6 +577,10 @@ int udhcpc_main(int argc, char **argv)
                         switch (signo) {
                         case SIGUSR1:
                                 perform_renew();
+                                /* start things over */
+                                packet_num = 0;
+                                /* Kill any timeouts because the user wants this to hurry along */
+                                timeout = 0;
                                 break;
                         case SIGUSR2:
                                 perform_release();
diff --git a/networking/udhcp/dhcpd.h b/networking/udhcp/dhcpd.h
index 28106d306..216b7ab64 100644
--- a/networking/udhcp/dhcpd.h
+++ b/networking/udhcp/dhcpd.h
@@ -100,7 +100,7 @@ int send_inform(struct dhcpMessage *oldpacket);
 int read_config(const char *file);
 void write_leases(void);
 void read_leases(const char *file);
-struct option_set *find_option(struct option_set *opt_list, char code);
+struct option_set *find_option(struct option_set *opt_list, uint8_t code);
 
 
 #endif
diff --git a/networking/udhcp/files.c b/networking/udhcp/files.c
index 5026598d7..63c90647d 100644
--- a/networking/udhcp/files.c
+++ b/networking/udhcp/files.c
@@ -71,7 +71,7 @@ static int read_yn(const char *line, void *arg)
 
 
 /* find option 'code' in opt_list */
-struct option_set *find_option(struct option_set *opt_list, char code)
+struct option_set *find_option(struct option_set *opt_list, uint8_t code)
 {
         while (opt_list && opt_list->data[OPT_CODE] < code)
                 opt_list = opt_list->next;
@@ -154,31 +154,29 @@ static int read_opt(const char *const_line, void *arg)
 {
         struct option_set **opt_list = arg;
         char *opt, *val, *endptr;
-        const struct dhcp_option *option;
-        int retval = 0, length;
-        char buffer[8];
         char *line;
+        const struct dhcp_option *option;
+        int retval, length, idx;
+        char buffer[8] __attribute__((aligned(4)));
         uint16_t *result_u16 = (uint16_t *) buffer;
         uint32_t *result_u32 = (uint32_t *) buffer;
 
         /* Cheat, the only const line we'll actually get is "" */
         line = (char *) const_line;
         opt = strtok(line, " \t=");
-        if (!opt) return 0;
+        if (!opt)
+                return 0;
 
-        option = dhcp_options;
-        while (1) {
-                if (!option->code)
-                        return 0;
-                if (!strcasecmp(option->opt_name, opt))
-                        break;
-                option++;
-        }
+        idx = index_in_strings(opt, dhcp_option_strings); /* NB: was strcasecmp! */
+        if (idx < 0)
+                return 0;
+        option = &dhcp_options[idx];
 
+        retval = 0;
         do {
                 val = strtok(NULL, ", \t");
                 if (!val) break;
-                length = option_lengths[option->flags & TYPE_MASK];
+                length = dhcp_option_lengths[option->flags & TYPE_MASK];
                 retval = 0;
                 opt = buffer; /* new meaning for variable opt */
                 switch (option->flags & TYPE_MASK) {
diff --git a/networking/udhcp/leases.c b/networking/udhcp/leases.c
index 60e9edc68..1745fee03 100644
--- a/networking/udhcp/leases.c
+++ b/networking/udhcp/leases.c
@@ -98,7 +98,9 @@ struct dhcpOfferedAddr *find_lease_by_yiaddr(uint32_t yiaddr)
 /* check is an IP is taken, if it is, add it to the lease table */
 static int nobody_responds_to_arp(uint32_t addr)
 {
-        static const uint8_t blank_chaddr[16]; /* 16 zero bytes */
+        /* 16 zero bytes */
+        static const uint8_t blank_chaddr[16] = { 0 };
+        /* = { 0 } helps gcc to put it in rodata, not bss */
 
         struct in_addr temp;
         int r;
diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c
index ffc0ed127..c224f3670 100644
--- a/networking/udhcp/options.c
+++ b/networking/udhcp/options.c
@@ -11,54 +11,97 @@
 
 /* Supported options are easily added here */
 const struct dhcp_option dhcp_options[] = {
-        /* opt_name[12] flags                                   code */
-        {"subnet",      OPTION_IP | OPTION_REQ,                 0x01},   /* DHCP_SUBNET         */
-        {"timezone",    OPTION_S32,                             0x02},   /* DHCP_TIME_OFFSET    */
-        {"router",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x03},   /* DHCP_ROUTER         */
-        {"timesvr",     OPTION_IP | OPTION_LIST,                0x04},   /* DHCP_TIME_SERVER    */
-        {"namesvr",     OPTION_IP | OPTION_LIST,                0x05},   /* DHCP_NAME_SERVER    */
-        {"dns",         OPTION_IP | OPTION_LIST | OPTION_REQ,   0x06},   /* DHCP_DNS_SERVER     */
-        {"logsvr",      OPTION_IP | OPTION_LIST,                0x07},   /* DHCP_LOG_SERVER     */
-        {"cookiesvr",   OPTION_IP | OPTION_LIST,                0x08},   /* DHCP_COOKIE_SERVER  */
-        {"lprsvr",      OPTION_IP | OPTION_LIST,                0x09},   /* DHCP_LPR_SERVER     */
-        {"hostname",    OPTION_STRING | OPTION_REQ,             0x0c},   /* DHCP_HOST_NAME      */
-        {"bootsize",    OPTION_U16,                             0x0d},   /* DHCP_BOOT_SIZE      */
-        {"domain",      OPTION_STRING | OPTION_LIST | OPTION_REQ, 0x0f}, /* DHCP_DOMAIN_NAME    */
-        {"swapsvr",     OPTION_IP,                              0x10},   /* DHCP_SWAP_SERVER    */
-        {"rootpath",    OPTION_STRING,                          0x11},   /* DHCP_ROOT_PATH      */
-        {"ipttl",       OPTION_U8,                              0x17},   /* DHCP_IP_TTL         */
-        {"mtu",         OPTION_U16,                             0x1a},   /* DHCP_MTU            */
-        {"broadcast",   OPTION_IP | OPTION_REQ,                 0x1c},   /* DHCP_BROADCAST      */
-        {"nisdomain",   OPTION_STRING | OPTION_REQ,             0x28},   /* DHCP_NTP_SERVER     */
-        {"nissrv",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x29},   /* DHCP_WINS_SERVER    */
-        {"ntpsrv",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x2a},   /* DHCP_REQUESTED_IP   */
-        {"wins",        OPTION_IP | OPTION_LIST,                0x2c},   /* DHCP_LEASE_TIME     */
-        {"requestip",   OPTION_IP,                              0x32},   /* DHCP_OPTION_OVER    */
-        {"lease",       OPTION_U32,                             0x33},   /* DHCP_MESSAGE_TYPE   */
-        {"dhcptype",    OPTION_U8,                              0x35},   /* DHCP_SERVER_ID      */
-        {"serverid",    OPTION_IP,                              0x36},   /* DHCP_PARAM_REQ      */
-        {"message",     OPTION_STRING,                          0x38},   /* DHCP_MESSAGE        */
-// TODO: 1) some options should not be parsed & passed to script -
-// maxsize sure should not, since it cannot appear in server responses!
-// grep for opt_name is fix the mess.
-// 2) Using fixed-sized char[] vector wastes space.
-        {"maxsize",     OPTION_U16,                             0x39},   /* DHCP_MAX_SIZE       */
-        {"vendorclass", OPTION_STRING,                          0x3C},   /* DHCP_VENDOR         */
-        {"clientid",    OPTION_STRING,                          0x3D},   /* DHCP_CLIENT_ID      */
-        {"tftp",        OPTION_STRING,                          0x42},
-        {"bootfile",    OPTION_STRING,                          0x43},
-        {"userclass",   OPTION_STRING,                          0x4D},
+        /* flags                                     code */
+        { OPTION_IP | OPTION_REQ,                    0x01 }, /* DHCP_SUBNET        */
+        { OPTION_S32,                                0x02 }, /* DHCP_TIME_OFFSET   */
+        { OPTION_IP | OPTION_LIST | OPTION_REQ,      0x03 }, /* DHCP_ROUTER        */
+        { OPTION_IP | OPTION_LIST,                   0x04 }, /* DHCP_TIME_SERVER   */
+        { OPTION_IP | OPTION_LIST,                   0x05 }, /* DHCP_NAME_SERVER   */
+        { OPTION_IP | OPTION_LIST | OPTION_REQ,      0x06 }, /* DHCP_DNS_SERVER    */
+        { OPTION_IP | OPTION_LIST,                   0x07 }, /* DHCP_LOG_SERVER    */
+        { OPTION_IP | OPTION_LIST,                   0x08 }, /* DHCP_COOKIE_SERVER */
+        { OPTION_IP | OPTION_LIST,                   0x09 }, /* DHCP_LPR_SERVER    */
+        { OPTION_STRING | OPTION_REQ,                0x0c }, /* DHCP_HOST_NAME     */
+        { OPTION_U16,                                0x0d }, /* DHCP_BOOT_SIZE     */
+        { OPTION_STRING | OPTION_LIST | OPTION_REQ,  0x0f }, /* DHCP_DOMAIN_NAME   */
+        { OPTION_IP,                                 0x10 }, /* DHCP_SWAP_SERVER   */
+        { OPTION_STRING,                             0x11 }, /* DHCP_ROOT_PATH     */
+        { OPTION_U8,                                 0x17 }, /* DHCP_IP_TTL        */
+        { OPTION_U16,                                0x1a }, /* DHCP_MTU           */
+        { OPTION_IP | OPTION_REQ,                    0x1c }, /* DHCP_BROADCAST     */
+        { OPTION_STRING | OPTION_REQ,                0x28 }, /* DHCP_NTP_SERVER    */
+        { OPTION_IP | OPTION_LIST | OPTION_REQ,      0x29 }, /* DHCP_WINS_SERVER   */
+        { OPTION_IP | OPTION_LIST | OPTION_REQ,      0x2a }, /* DHCP_REQUESTED_IP  */
+        { OPTION_IP | OPTION_LIST,                   0x2c }, /* DHCP_LEASE_TIME    */
+        { OPTION_IP,                                 0x32 }, /* DHCP_OPTION_OVER   */
+        { OPTION_U32,                                0x33 }, /* DHCP_MESSAGE_TYPE  */
+        { OPTION_U8,                                 0x35 }, /* DHCP_SERVER_ID     */
+        { OPTION_IP,                                 0x36 }, /* DHCP_PARAM_REQ     */
+        { OPTION_STRING,                             0x38 }, /* DHCP_MESSAGE       */
+        { OPTION_STRING,                             0x3C }, /* DHCP_VENDOR        */
+        { OPTION_STRING,                             0x3D }, /* DHCP_CLIENT_ID     */
+        { OPTION_STRING,                             0x42 }, /* "tftp"             */
+        { OPTION_STRING,                             0x43 }, /* "bootfile"         */
+        { OPTION_STRING,                             0x4D }, /* "userclass"        */
 #if ENABLE_FEATURE_RFC3397
-        {"search",      OPTION_STR1035 | OPTION_LIST | OPTION_REQ, 0x77},
+        { OPTION_STR1035 | OPTION_LIST | OPTION_REQ, 0x77 }, /* "search"           */
 #endif
         /* MSIE's "Web Proxy Autodiscovery Protocol" support */
-        {"wpad",        OPTION_STRING,                          0xfc},
-        {} /* zero-padded terminating entry */
+        { OPTION_STRING,                             0xfc }, /* "wpad"             */
+
+        /* Options below have no match in dhcp_option_strings[],
+         * are not passed to dhcpc scripts, and cannot be specified
+         * with "option XXX YYY" syntax in dhcpd config file. */
+
+        { OPTION_U16,                                0x39 }, /* DHCP_MAX_SIZE      */
+        { } /* zeroed terminating entry */
 };
 
+/* Used for converting options from incoming packets to env variables
+ * for udhcpc stript */
+/* Must match dhcp_options[] order */
+const char dhcp_option_strings[] ALIGN1 =
+        "subnet" "\0"      /* DHCP_SUBNET         */
+        "timezone" "\0"    /* DHCP_TIME_OFFSET    */
+        "router" "\0"      /* DHCP_ROUTER         */
+        "timesvr" "\0"     /* DHCP_TIME_SERVER    */
+        "namesvr" "\0"     /* DHCP_NAME_SERVER    */
+        "dns" "\0"         /* DHCP_DNS_SERVER     */
+        "logsvr" "\0"      /* DHCP_LOG_SERVER     */
+        "cookiesvr" "\0"   /* DHCP_COOKIE_SERVER  */
+        "lprsvr" "\0"      /* DHCP_LPR_SERVER     */
+        "hostname" "\0"    /* DHCP_HOST_NAME      */
+        "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
+        "domain" "\0"      /* DHCP_DOMAIN_NAME    */
+        "swapsvr" "\0"     /* DHCP_SWAP_SERVER    */
+        "rootpath" "\0"    /* DHCP_ROOT_PATH      */
+        "ipttl" "\0"       /* DHCP_IP_TTL         */
+        "mtu" "\0"         /* DHCP_MTU            */
+        "broadcast" "\0"   /* DHCP_BROADCAST      */
+        "nisdomain" "\0"   /* DHCP_NTP_SERVER     */
+        "nissrv" "\0"      /* DHCP_WINS_SERVER    */
+        "ntpsrv" "\0"      /* DHCP_REQUESTED_IP   */
+        "wins" "\0"        /* DHCP_LEASE_TIME     */
+        "requestip" "\0"   /* DHCP_OPTION_OVER    */
+        "lease" "\0"       /* DHCP_MESSAGE_TYPE   */
+        "dhcptype" "\0"    /* DHCP_SERVER_ID      */
+        "serverid" "\0"    /* DHCP_PARAM_REQ      */
+        "message" "\0"     /* DHCP_MESSAGE        */
+        "vendorclass" "\0" /* DHCP_VENDOR         */
+        "clientid" "\0"    /* DHCP_CLIENT_ID      */
+        "tftp" "\0"
+        "bootfile" "\0"
+        "userclass" "\0"
+#if ENABLE_FEATURE_RFC3397
+        "search" "\0"
+#endif
+        /* MSIE's "Web Proxy Autodiscovery Protocol" support */
+        "wpad" "\0"
+        ;
+
 
 /* Lengths of the different option types */
-const unsigned char option_lengths[] ALIGN1 = {
+const uint8_t dhcp_option_lengths[] ALIGN1 = {
         [OPTION_IP] =      4,
         [OPTION_IP_PAIR] = 8,
         [OPTION_BOOLEAN] = 1,
@@ -137,8 +180,10 @@ int end_option(uint8_t *optionptr)
         int i = 0;
 
         while (optionptr[i] != DHCP_END) {
-                if (optionptr[i] == DHCP_PADDING) i++;
-                else i += optionptr[i + OPT_LEN] + 2;
+                if (optionptr[i] == DHCP_PADDING)
+                        i++;
+                else
+                        i += optionptr[i + OPT_LEN] + 2;
         }
         return i;
 }
@@ -173,10 +218,11 @@ int add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
                         uint8_t option[6], len;
 
                         option[OPT_CODE] = code;
-                        len = option_lengths[dh->flags & TYPE_MASK];
+                        len = dhcp_option_lengths[dh->flags & TYPE_MASK];
                         option[OPT_LEN] = len;
-                        if (BB_BIG_ENDIAN) data <<= 8 * (4 - len);
-                        /* This memcpy is for broken processors which can't
+                        if (BB_BIG_ENDIAN)
+                                data <<= 8 * (4 - len);
+                        /* This memcpy is for processors which can't
                          * handle a simple unaligned 32-bit assignment */
                         memcpy(&option[OPT_DATA], &data, 4);
                         return add_option_string(optionptr, option);
diff --git a/networking/udhcp/options.h b/networking/udhcp/options.h
index 4bf73a17e..c98aec48f 100644
--- a/networking/udhcp/options.h
+++ b/networking/udhcp/options.h
@@ -98,13 +98,13 @@ enum {
 #define OPT_DATA 2
 
 struct dhcp_option {
-        char opt_name[12];
-        char flags;
+        uint8_t flags;
         uint8_t code;
 };
 
 extern const struct dhcp_option dhcp_options[];
-extern const unsigned char option_lengths[];
+extern const char dhcp_option_strings[];
+extern const uint8_t dhcp_option_lengths[];
 
 uint8_t *get_option(struct dhcpMessage *packet, int code);
 int end_option(uint8_t *optionptr);
diff --git a/networking/udhcp/script.c b/networking/udhcp/script.c
index 33d96e687..8a188988e 100644
--- a/networking/udhcp/script.c
+++ b/networking/udhcp/script.c
@@ -33,7 +33,7 @@ static const uint8_t max_option_length[] = {
 static inline int upper_length(int length, int opt_index)
 {
         return max_option_length[opt_index] *
-                (length / option_lengths[opt_index]);
+                (length / dhcp_option_lengths[opt_index]);
 }
 
 
@@ -57,7 +57,7 @@ static int mton(uint32_t mask)
 
 
 /* Allocate and fill with the text of option 'option'. */
-static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
+static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p, const char *opt_name)
 {
         int len, type, optlen;
         uint16_t val_u16;
@@ -68,10 +68,10 @@ static char *alloc_fill_opts(uint8_t *option, const struct dhcp_option *type_p)
 
         len = option[OPT_LEN - 2];
         type = type_p->flags & TYPE_MASK;
-        optlen = option_lengths[type];
+        optlen = dhcp_option_lengths[type];
 
-        dest = ret = xmalloc(upper_length(len, type) + strlen(type_p->opt_name) + 2);
-        dest += sprintf(ret, "%s=", type_p->opt_name);
+        dest = ret = xmalloc(upper_length(len, type) + strlen(opt_name) + 2);
+        dest += sprintf(ret, "%s=", opt_name);
 
         for (;;) {
                 switch (type) {
@@ -133,6 +133,7 @@ static char **fill_envp(struct dhcpMessage *packet)
         int i, j;
         char **envp;
         char *var;
+        const char *opt_name;
         uint8_t *temp;
         char over = 0;
 
@@ -171,11 +172,13 @@ static char **fill_envp(struct dhcpMessage *packet)
         envp[j] = xmalloc(sizeof("ip=255.255.255.255"));
         sprintip(envp[j++], "ip=", (uint8_t *) &packet->yiaddr);
 
-        for (i = 0; dhcp_options[i].code; i++) {
+        opt_name = dhcp_option_strings;
+        i = 0;
+        while (*opt_name) {
                 temp = get_option(packet, dhcp_options[i].code);
                 if (!temp)
-                        continue;
-                envp[j++] = alloc_fill_opts(temp, &dhcp_options[i]);
+                        goto next;
+                envp[j++] = alloc_fill_opts(temp, &dhcp_options[i], opt_name);
 
                 /* Fill in a subnet bits option for things like /24 */
                 if (dhcp_options[i].code == DHCP_SUBNET) {
@@ -183,6 +186,9 @@ static char **fill_envp(struct dhcpMessage *packet)
                         memcpy(&subnet, temp, 4);
                         envp[j++] = xasprintf("mask=%d", mton(subnet));
                 }
+ next:
+                opt_name += strlen(opt_name) + 1;
+                i++;
         }
         if (packet->siaddr) {
                 envp[j] = xmalloc(sizeof("siaddr=255.255.255.255"));