lpr: add more accurate comments
[oweals/busybox.git] / networking / udhcp / options.c
index ae9819413951ece3c54d53afee9002131b3120a4..12e56621087defeac85906da2f5133811279fdc5 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
  * options.c -- DHCP server option packet tools
  * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
  */
 
-#include <stdlib.h>
-#include <string.h>
-
+#include "common.h"
 #include "dhcpd.h"
-#include "files.h"
 #include "options.h"
-#include "common.h"
 
 
-/* supported options are easily added here */
-struct dhcp_option dhcp_options[] = {
-       /* name[10]     flags                                   code */
-       {"subnet",      OPTION_IP | OPTION_REQ,                 0x01},
-       {"timezone",    OPTION_S32,                             0x02},
-       {"router",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x03},
-       {"timesvr",     OPTION_IP | OPTION_LIST,                0x04},
-       {"namesvr",     OPTION_IP | OPTION_LIST,                0x05},
-       {"dns",         OPTION_IP | OPTION_LIST | OPTION_REQ,   0x06},
-       {"logsvr",      OPTION_IP | OPTION_LIST,                0x07},
-       {"cookiesvr",   OPTION_IP | OPTION_LIST,                0x08},
-       {"lprsvr",      OPTION_IP | OPTION_LIST,                0x09},
-       {"hostname",    OPTION_STRING | OPTION_REQ,             0x0c},
-       {"bootsize",    OPTION_U16,                             0x0d},
-       {"domain",      OPTION_STRING | OPTION_REQ,             0x0f},
-       {"swapsvr",     OPTION_IP,                              0x10},
-       {"rootpath",    OPTION_STRING,                          0x11},
-       {"ipttl",       OPTION_U8,                              0x17},
-       {"mtu",         OPTION_U16,                             0x1a},
-       {"broadcast",   OPTION_IP | OPTION_REQ,                 0x1c},
-       {"nisdomain",   OPTION_STRING | OPTION_REQ,             0x28},
-       {"nissrv",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x29},
-       {"ntpsrv",      OPTION_IP | OPTION_LIST | OPTION_REQ,   0x2a},
-       {"wins",        OPTION_IP | OPTION_LIST,                0x2c},
-       {"requestip",   OPTION_IP,                              0x32},
-       {"lease",       OPTION_U32,                             0x33},
-       {"dhcptype",    OPTION_U8,                              0x35},
-       {"serverid",    OPTION_IP,                              0x36},
-       {"message",     OPTION_STRING,                          0x38},
-       {"tftp",        OPTION_STRING,                          0x42},
-       {"bootfile",    OPTION_STRING,                          0x43},
-       {"",            0x00,                           0x00}
+/* Supported options are easily added here */
+const struct dhcp_option dhcp_options[] = {
+       /* 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                           , 0x28 }, /* nisdomain          */
+       { OPTION_IP | OPTION_LIST                 , 0x29 }, /* nissrv             */
+       { OPTION_IP | OPTION_LIST     | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER    */
+       { OPTION_IP | OPTION_LIST                 , 0x2c }, /* DHCP_WINS_SERVER   */
+       { OPTION_IP                               , 0x32 }, /* DHCP_REQUESTED_IP  */
+       { OPTION_U32                              , 0x33 }, /* DHCP_LEASE_TIME    */
+       { OPTION_U8                               , 0x35 }, /* dhcptype           */
+       { OPTION_IP                               , 0x36 }, /* DHCP_SERVER_ID     */
+       { 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
+       { OPTION_STR1035 | OPTION_LIST            , 0x77 }, /* search             */
+#endif
+       /* MSIE's "Web Proxy Autodiscovery Protocol" support */
+       { 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         */
+       "timesrv" "\0"     /* DHCP_TIME_SERVER    */
+       "namesrv" "\0"     /* DHCP_NAME_SERVER    */
+       "dns" "\0"         /* DHCP_DNS_SERVER     */
+       "logsrv" "\0"      /* DHCP_LOG_SERVER     */
+       "cookiesrv" "\0"   /* DHCP_COOKIE_SERVER  */
+       "lprsrv" "\0"      /* DHCP_LPR_SERVER     */
+       "hostname" "\0"    /* DHCP_HOST_NAME      */
+       "bootsize" "\0"    /* DHCP_BOOT_SIZE      */
+       "domain" "\0"      /* DHCP_DOMAIN_NAME    */
+       "swapsrv" "\0"     /* DHCP_SWAP_SERVER    */
+       "rootpath" "\0"    /* DHCP_ROOT_PATH      */
+       "ipttl" "\0"       /* DHCP_IP_TTL         */
+       "mtu" "\0"         /* DHCP_MTU            */
+       "broadcast" "\0"   /* DHCP_BROADCAST      */
+       "nisdomain" "\0"   /*                     */
+       "nissrv" "\0"      /*                     */
+       "ntpsrv" "\0"      /* DHCP_NTP_SERVER     */
+       "wins" "\0"        /* DHCP_WINS_SERVER    */
+       "requestip" "\0"   /* DHCP_REQUESTED_IP   */
+       "lease" "\0"       /* DHCP_LEASE_TIME     */
+       "dhcptype" "\0"    /*                     */
+       "serverid" "\0"    /* DHCP_SERVER_ID      */
+       "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 */
-int option_lengths[] = {
-       [OPTION_IP] =           4,
-       [OPTION_IP_PAIR] =      8,
-       [OPTION_BOOLEAN] =      1,
-       [OPTION_STRING] =       1,
-       [OPTION_U8] =           1,
-       [OPTION_U16] =          2,
-       [OPTION_S16] =          2,
-       [OPTION_U32] =          4,
-       [OPTION_S32] =          4
+const uint8_t dhcp_option_lengths[] ALIGN1 = {
+       [OPTION_IP] =      4,
+       [OPTION_IP_PAIR] = 8,
+       [OPTION_BOOLEAN] = 1,
+       [OPTION_STRING] =  1,
+#if ENABLE_FEATURE_RFC3397
+       [OPTION_STR1035] = 1,
+#endif
+       [OPTION_U8] =      1,
+       [OPTION_U16] =     2,
+       [OPTION_S16] =     2,
+       [OPTION_U32] =     4,
+       [OPTION_S32] =     4
 };
 
 
@@ -65,19 +122,20 @@ uint8_t *get_option(struct dhcpMessage *packet, int code)
 {
        int i, length;
        uint8_t *optionptr;
-       int over = 0, done = 0, curr = OPTION_FIELD;
+       int over = 0;
+       int curr = OPTION_FIELD;
 
        optionptr = packet->options;
        i = 0;
-       length = 308;
-       while (!done) {
+       length = sizeof(packet->options);
+       while (1) {
                if (i >= length) {
-                       LOG(LOG_WARNING, "bogus packet, option fields too long.");
+                       bb_error_msg("bogus packet, option fields too long");
                        return NULL;
                }
                if (optionptr[i + OPT_CODE] == code) {
                        if (i + 1 + optionptr[i + OPT_LEN] >= length) {
-                               LOG(LOG_WARNING, "bogus packet, option fields too long.");
+                               bb_error_msg("bogus packet, option fields too long");
                                return NULL;
                        }
                        return optionptr + i + 2;
@@ -88,24 +146,25 @@ uint8_t *get_option(struct dhcpMessage *packet, int code)
                        break;
                case DHCP_OPTION_OVER:
                        if (i + 1 + optionptr[i + OPT_LEN] >= length) {
-                               LOG(LOG_WARNING, "bogus packet, option fields too long.");
+                               bb_error_msg("bogus packet, option fields too long");
                                return NULL;
                        }
                        over = optionptr[i + 3];
                        i += optionptr[OPT_LEN] + 2;
                        break;
                case DHCP_END:
-                       if (curr == OPTION_FIELD && over & FILE_FIELD) {
+                       if (curr == OPTION_FIELD && (over & FILE_FIELD)) {
                                optionptr = packet->file;
                                i = 0;
-                               length = 128;
+                               length = sizeof(packet->file);
                                curr = FILE_FIELD;
-                       } else if (curr == FILE_FIELD && over & SNAME_FIELD) {
+                       } else if (curr == FILE_FIELD && (over & SNAME_FIELD)) {
                                optionptr = packet->sname;
                                i = 0;
-                               length = 64;
+                               length = sizeof(packet->sname);
                                curr = SNAME_FIELD;
-                       } else done = 1;
+                       } else
+                               return NULL;
                        break;
                default:
                        i += optionptr[OPT_LEN + i] + 2;
@@ -121,8 +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;
 }
@@ -135,11 +196,12 @@ int add_option_string(uint8_t *optionptr, uint8_t *string)
        int end = end_option(optionptr);
 
        /* end position + string length + option code/length + end option */
-       if (end + string[OPT_LEN] + 2 + 1 >= 308) {
-               LOG(LOG_ERR, "Option 0x%02x did not fit into the packet!", string[OPT_CODE]);
+       if (end + string[OPT_LEN] + 2 + 1 >= DHCP_OPTIONS_BUFSIZE) {
+               bb_error_msg("option 0x%02x did not fit into the packet",
+                               string[OPT_CODE]);
                return 0;
        }
-       DEBUG(LOG_INFO, "adding option 0x%02x", string[OPT_CODE]);
+       DEBUG("adding option 0x%02x", string[OPT_CODE]);
        memcpy(optionptr + end, string, string[OPT_LEN] + 2);
        optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
        return string[OPT_LEN] + 2;
@@ -149,82 +211,24 @@ int add_option_string(uint8_t *optionptr, uint8_t *string)
 /* add a one to four byte option to a packet */
 int add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
 {
-       char length = 0;
-       int i;
-       uint8_t option[2 + 4];
-       uint8_t *u8;
-       uint16_t *u16;
-       uint32_t *u32;
-       uint32_t aligned;
-       u8 = (uint8_t *) &aligned;
-       u16 = (uint16_t *) &aligned;
-       u32 = &aligned;
-
-       for (i = 0; dhcp_options[i].code; i++)
-               if (dhcp_options[i].code == code) {
-                       length = option_lengths[dhcp_options[i].flags & TYPE_MASK];
+       const struct dhcp_option *dh;
+
+       for (dh = dhcp_options; dh->code; dh++) {
+               if (dh->code == code) {
+                       uint8_t option[6], len;
+
+                       option[OPT_CODE] = code;
+                       len = dhcp_option_lengths[dh->flags & TYPE_MASK];
+                       option[OPT_LEN] = len;
+                       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);
                }
-
-       if (!length) {
-               DEBUG(LOG_ERR, "Could not add option 0x%02x", code);
-               return 0;
        }
 
-       option[OPT_CODE] = code;
-       option[OPT_LEN] = length;
-
-       switch (length) {
-               case 1: *u8 =  data; break;
-               case 2: *u16 = data; break;
-               case 4: *u32 = data; break;
-       }
-       memcpy(option + 2, &aligned, length);
-       return add_option_string(optionptr, option);
-}
-
-
-/* find option 'code' in opt_list */
-struct option_set *find_option(struct option_set *opt_list, char code)
-{
-       while (opt_list && opt_list->data[OPT_CODE] < code)
-               opt_list = opt_list->next;
-
-       if (opt_list && opt_list->data[OPT_CODE] == code) return opt_list;
-       else return NULL;
-}
-
-
-/* add an option to the opt_list */
-void attach_option(struct option_set **opt_list, struct dhcp_option *option, char *buffer, int length)
-{
-       struct option_set *existing, *new, **curr;
-
-       /* add it to an existing option */
-       if ((existing = find_option(*opt_list, option->code))) {
-               DEBUG(LOG_INFO, "Attaching option %s to existing member of list", option->name);
-               if (option->flags & OPTION_LIST) {
-                       if (existing->data[OPT_LEN] + length <= 255) {
-                               existing->data = realloc(existing->data,
-                                               existing->data[OPT_LEN] + length + 2);
-                               memcpy(existing->data + existing->data[OPT_LEN] + 2, buffer, length);
-                               existing->data[OPT_LEN] += length;
-                       } /* else, ignore the data, we could put this in a second option in the future */
-               } /* else, ignore the new data */
-       } else {
-               DEBUG(LOG_INFO, "Attaching option %s to list", option->name);
-
-               /* make a new option */
-               new = xmalloc(sizeof(struct option_set));
-               new->data = xmalloc(length + 2);
-               new->data[OPT_CODE] = option->code;
-               new->data[OPT_LEN] = length;
-               memcpy(new->data + 2, buffer, length);
-
-               curr = opt_list;
-               while (*curr && (*curr)->data[OPT_CODE] < option->code)
-                       curr = &(*curr)->next;
-
-               new->next = *curr;
-               *curr = new;
-       }
+       bb_error_msg("cannot add option 0x%02x", code);
+       return 0;
 }