Diff: modules/pico_dhcp_common.c

Revision:

63:97f481e33cb2

Parent:

51:ab4529a384a6

--- a/modules/pico_dhcp_common.c	Mon Sep 16 12:07:35 2013 +0000
+++ b/modules/pico_dhcp_common.c	Thu Sep 19 12:38:53 2013 +0000
@@ -12,174 +12,56 @@
 #include "pico_dhcp_common.h"
 
 #if defined (PICO_SUPPORT_DHCPC) || defined (PICO_SUPPORT_DHCPD)
-/* pico_dhcp_are_options_valid needs to be called first to prevent illegal memory access */
-/* The argument pointer is moved forward to the next option */
-struct pico_dhcp_opt *pico_dhcp_next_option(struct pico_dhcp_opt **ptr)
+//this function should only be used after you checked if the options are valid! otherwise it could read from bad memory!
+uint8_t dhcp_get_next_option(uint8_t *begin, uint8_t *data, int *len, uint8_t **nextopt)
 {
-  uint8_t **p = (uint8_t **)ptr;
-  struct pico_dhcp_opt *opt = *ptr;
+	uint8_t *p;
+	uint8_t type;
+	uint8_t opt_len;
+
+	if (!begin)
+		p = *nextopt;
+	else
+		p = begin;
 
-	if (opt->code == PICO_DHCP_OPT_END)
-    return NULL;
-  if (opt->code == PICO_DHCP_OPT_PAD) {
-    *p += 1; 
-		return *ptr;
-  }
-
-  *p += (opt->len + 2); /* (len + 2) to account for code and len octet */
-  return *ptr;
+	type = *p;
+	*nextopt = ++p;
+	if ((type == PICO_DHCPOPT_END) || (type == PICO_DHCPOPT_PAD)) {
+		memset(data, 0, *len);
+		len = 0;
+		return type;
+	}
+	opt_len = *p;
+	p++;
+	if (*len > opt_len)
+		*len = opt_len;
+	memcpy(data, p, *len);
+	*nextopt = p + opt_len;
+	return type;
 }
 
-int pico_dhcp_are_options_valid(void *ptr, int len)
+int is_options_valid(uint8_t *opt_buffer, int len)
 {
-	uint8_t optlen = 0, *p = ptr;
-
+	uint8_t *p = opt_buffer;
 	while (len > 0) {
-    switch (*p)
-    {
-      case PICO_DHCP_OPT_END:
-        return 1;
-
-      case PICO_DHCP_OPT_PAD:
-        p++;
-        len--;
-        break;
-
-      default:
-        p++; /* move pointer from code octet to len octet */
-        if ((--len <= 0) || (len - (*p + 1) < 0)) /* (*p + 1) to account for len octet */
-          return 0;
-        optlen = *p;
-        p += optlen + 1;
-        len -= optlen;
-        break;
-    }
+		if (*p == PICO_DHCPOPT_END)
+			return 1;
+		else if (*p == PICO_DHCPOPT_PAD) {
+			p++;
+			len--;
+		} else {
+			uint8_t opt_len;
+			p++;
+			len--;
+			if(len > 0) {
+				opt_len = *p;
+				p += opt_len + 1;
+				len -= opt_len;
+			}else
+				return 0;
+		}
 	}
 	return 0;
 }
 
-int pico_dhcp_opt_netmask(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: netmask */
-  opt->code = PICO_DHCP_OPT_NETMASK;
-  opt->len = PICO_DHCP_OPTLEN_NETMASK - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.netmask.ip = *ip;
-  return PICO_DHCP_OPTLEN_NETMASK;
-}
-
-int pico_dhcp_opt_router(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: router */
-  opt->code = PICO_DHCP_OPT_ROUTER;
-  opt->len = PICO_DHCP_OPTLEN_ROUTER - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.router.ip = *ip;
-  return PICO_DHCP_OPTLEN_ROUTER;
-}
-
-int pico_dhcp_opt_dns(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: dns */
-  opt->code = PICO_DHCP_OPT_DNS;
-  opt->len = PICO_DHCP_OPTLEN_DNS - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.dns.ip = *ip;
-  return PICO_DHCP_OPTLEN_DNS;
-}
-
-int pico_dhcp_opt_broadcast(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: broadcast */
-  opt->code = PICO_DHCP_OPT_BROADCAST;
-  opt->len = PICO_DHCP_OPTLEN_BROADCAST - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.broadcast.ip = *ip;
-  return PICO_DHCP_OPTLEN_BROADCAST;
-}
-
-int pico_dhcp_opt_reqip(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: request IP address */
-  opt->code = PICO_DHCP_OPT_REQIP;
-  opt->len = PICO_DHCP_OPTLEN_REQIP - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.req_ip.ip = *ip;
-  return PICO_DHCP_OPTLEN_REQIP;
-}
-
-int pico_dhcp_opt_leasetime(void *ptr, uint32_t time)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: lease time */
-  opt->code = PICO_DHCP_OPT_LEASETIME;
-  opt->len = PICO_DHCP_OPTLEN_LEASETIME - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.lease_time.time = time;
-  return PICO_DHCP_OPTLEN_LEASETIME;
-}
-
-int pico_dhcp_opt_msgtype(void *ptr, uint8_t type)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: message type */
-  opt->code = PICO_DHCP_OPT_MSGTYPE;
-  opt->len = PICO_DHCP_OPTLEN_MSGTYPE - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.msg_type.type = type;
-  return PICO_DHCP_OPTLEN_MSGTYPE;
-}
-
-int pico_dhcp_opt_serverid(void *ptr, struct pico_ip4 *ip)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: server identifier */
-  opt->code = PICO_DHCP_OPT_SERVERID;
-  opt->len = PICO_DHCP_OPTLEN_SERVERID - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.server_id.ip = *ip;
-  return PICO_DHCP_OPTLEN_SERVERID;
-}
-
-int pico_dhcp_opt_paramlist(void *ptr)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: parameter list */
-  opt->code = PICO_DHCP_OPT_PARAMLIST;
-  opt->len = PICO_DHCP_OPTLEN_PARAMLIST - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.param_list.code[0] = PICO_DHCP_OPT_NETMASK;
-  opt->ext.param_list.code[1] = PICO_DHCP_OPT_TIME;
-  opt->ext.param_list.code[2] = PICO_DHCP_OPT_ROUTER;
-  opt->ext.param_list.code[3] = PICO_DHCP_OPT_HOSTNAME;
-  opt->ext.param_list.code[4] = PICO_DHCP_OPT_RENEWALTIME;
-  opt->ext.param_list.code[5] = PICO_DHCP_OPT_REBINDINGTIME;
-  return PICO_DHCP_OPTLEN_PARAMLIST;
-}
-
-int pico_dhcp_opt_maxmsgsize(void *ptr, uint16_t size)
-{
-  struct pico_dhcp_opt *opt = (struct pico_dhcp_opt *)ptr;
-
-  /* option: maximum message size */
-  opt->code = PICO_DHCP_OPT_MAXMSGSIZE;
-  opt->len = PICO_DHCP_OPTLEN_MAXMSGSIZE - PICO_DHCP_OPTLEN_HDR;
-  opt->ext.max_msg_size.size = short_be(size);
-  return PICO_DHCP_OPTLEN_MAXMSGSIZE;
-}
-
-int pico_dhcp_opt_end(void *ptr)
-{
-  uint8_t *opt = (uint8_t *)ptr;
-
-  /* option: end of options */
-  *opt = PICO_DHCP_OPT_END;
-  return PICO_DHCP_OPTLEN_END;
-}
-
 #endif