*****************************************************************************/
-/*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ALGORITHMS <<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/
+/******************************* ALGORITHMS ******************************/
/** \file dhcp.c <pre>
* **************** State-transition diagram for DHCP client *************
* </pre> */
-/*>>>>>>>>>>>>>>>>>>>>> DEFINITIONS & DECLARATIONS <<<<<<<<<<<<<<<<<<<<<<*/
+/********************** DEFINITIONS & DECLARATIONS ***********************/
#include <dhcp.h>
#include <ethernet.h>
#include <ipv4.h>
#include <udp.h>
#include <dns.h>
+#include <netapps/args.h>
#include <stdio.h>
#include <string.h>
* If flag[i] == TRUE then field for i-th option retains valid value and
* information from this field may retrived (in case of receiving) or will
* be transmitted (in case of transmitting).
- *
+ *
*/
typedef struct {
uint8_t flag[256]; /**< Show if corresponding opt. is valid */
- uint8_t request_list[256]; /**< o.55 If i-th member is TRUE, then i-th
+ uint8_t request_list[256]; /**< o.55 If i-th member is TRUE, then i-th
option will be requested from server */
uint32_t server_ID; /**< o.54 Identifies DHCP-server */
uint32_t requested_IP; /**< o.50 Must be filled in DHCP-Request */
static uint8_t dhcp_state;
-/*>>>>>>>>>>>>>>>>>>>>>>>>>>>> PROTOTYPES <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/
-
-static int32_t
-dhcp_attempt(int fd);
+/***************************** PROTOTYPES ********************************/
-static int32_t
-dhcp_encode_options(uint8_t * opt_field, dhcp_options_t * opt_struct);
+static int32_t dhcp_attempt(int fd);
-static int32_t
-dhcp_decode_options(uint8_t opt_field[], uint32_t opt_len,
- dhcp_options_t * opt_struct);
+static int32_t dhcp_encode_options(uint8_t * opt_field, dhcp_options_t * opt_struct);
-static int8_t
-dhcp_merge_options(uint8_t dst_options[], uint32_t * dst_len,
- uint8_t src_options[], uint32_t src_len);
+static int32_t dhcp_decode_options(uint8_t opt_field[], uint32_t opt_len,
+ dhcp_options_t * opt_struct);
-static int8_t
-dhcp_find_option(uint8_t options[], uint32_t len,
- uint8_t op_code, uint32_t * op_offset);
-
-static void
-dhcp_append_option(uint8_t dst_options[], uint32_t * dst_len,
- uint8_t * new_option);
+static int8_t dhcp_merge_options(uint8_t dst_options[], uint32_t * dst_len,
+ uint8_t src_options[], uint32_t src_len);
-static void
-dhcp_combine_option(uint8_t dst_options[], uint32_t * dst_len,
- uint32_t dst_offset, uint8_t * new_option);
+static int8_t dhcp_find_option(uint8_t options[], uint32_t len,
+ uint8_t op_code, uint32_t * op_offset);
-static void
-dhcp_send_discover(int fd);
+static void dhcp_append_option(uint8_t dst_options[], uint32_t * dst_len,
+ uint8_t * new_option);
-static void
-dhcp_send_request(int fd);
+static void dhcp_combine_option(uint8_t dst_options[], uint32_t * dst_len,
+ uint32_t dst_offset, uint8_t * new_option);
-static uint8_t
-strtoip(int8_t * str, uint32_t * ip);
+static void dhcp_send_discover(int fd);
+static void dhcp_send_request(int fd);
-/*>>>>>>>>>>>>>>>>>>>>>>>>>>>> LOCAL VARIABLES <<<<<<<<<<<<<<<<<<<<<<<<<<*/
+/***************************** LOCAL VARIABLES ***************************/
static uint8_t ether_packet[ETH_MTU_SIZE];
static uint32_t dhcp_own_ip = 0;
static uint32_t dhcp_server_ip = 0;
static uint32_t dhcp_siaddr_ip = 0;
-static int8_t dhcp_filename[256];
-static int8_t dhcp_tftp_name[256];
+static char dhcp_filename[256];
+static char dhcp_tftp_name[256];
+static uint32_t dhcp_xid;
static char * response_buffer;
-/*>>>>>>>>>>>>>>>>>>>>>>>>>>>> IMPLEMENTATION <<<<<<<<<<<<<<<<<<<<<<<<<<<*/
+/***************************** IMPLEMENTATION ****************************/
-int32_t
-dhcpv4(char *ret_buffer, filename_ip_t * fn_ip) {
+void dhcpv4_generate_transaction_id(void)
+{
+ dhcp_xid = (rand() << 16) ^ rand();
+}
+int32_t dhcpv4(char *ret_buffer, filename_ip_t *fn_ip)
+{
uint32_t dhcp_tftp_ip = 0;
int fd = fn_ip->fd;
- strcpy((char *) dhcp_filename, "");
- strcpy((char *) dhcp_tftp_name, "");
+ strcpy(dhcp_filename, "");
+ strcpy(dhcp_tftp_name, "");
response_buffer = ret_buffer;
dhcp_siaddr_ip = fn_ip->server_ip;
}
if(fn_ip->filename[0] != 0) {
- strcpy((char *) dhcp_filename, (char *) fn_ip->filename);
+ strcpy(dhcp_filename, (char *) fn_ip->filename);
}
// TFTP SERVER
- if (!strlen((char *) dhcp_tftp_name)) {
+ if (!strlen(dhcp_tftp_name)) {
if (!dhcp_siaddr_ip) {
// ERROR: TFTP name is not presented
return -3;
}
else {
// TFTP server defined by its name
- if (!strtoip(dhcp_tftp_name, &(dhcp_tftp_ip))) {
- if (!dns_get_ip(fd, dhcp_tftp_name, (uint8_t *)&(dhcp_tftp_ip), 4)) {
- // DNS error - can't obtain TFTP-server name
+ if (!strtoip(dhcp_tftp_name, (char *)&dhcp_tftp_ip)) {
+ if (!dns_get_ip(fd, dhcp_tftp_name, (uint8_t *)&dhcp_tftp_ip, 4)) {
+ // DNS error - can't obtain TFTP-server name
// Use TFTP-ip from siaddr field, if presented
if (dhcp_siaddr_ip) {
dhcp_tftp_ip = dhcp_siaddr_ip;
// Store configuration info into filename_ip strucutre
fn_ip -> own_ip = dhcp_own_ip;
fn_ip -> server_ip = dhcp_tftp_ip;
- strcpy((char *) fn_ip -> filename, (char *) dhcp_filename);
+ strcpy((char *) fn_ip -> filename, dhcp_filename);
return 0;
}
/**
* DHCP: Tries o obtain DHCP parameters, refer to state-transition diagram
*/
-static int32_t
-dhcp_attempt(int fd) {
+static int32_t dhcp_attempt(int fd)
+{
int sec;
// Send DISCOVER message and switch DHCP-client to SELECT state
} while (get_timer() > 0);
}
- // timeout
+ // timeout
return 0;
}
* DHCP: Supplements DHCP-message with options stored in structure.
* For more information about option coding see dhcp_options_t.
*
- * @param opt_field Points to the "vend" field of DHCP-message
+ * @param opt_field Points to the "vend" field of DHCP-message
* (destination)
* @param opt_struct this structure stores info about the options which
* will be added to DHCP-message (source)
* FALSE - error condition occurs.
* @see dhcp_options_t
*/
-static int32_t
-dhcp_encode_options(uint8_t * opt_field, dhcp_options_t * opt_struct) {
+static int32_t dhcp_encode_options(uint8_t * opt_field, dhcp_options_t * opt_struct)
+{
uint8_t * options = opt_field;
uint16_t i, sum; // used to define is any options set
* DHCP: Extracts encoded options from DHCP-message into the structure.
* For more information about option coding see dhcp_options_t.
*
- * @param opt_field Points to the "options" field of DHCP-message
+ * @param opt_field Points to the "options" field of DHCP-message
* (source).
* @param opt_len Length of "options" field.
* @param opt_struct this structure stores info about the options which
* FALSE - error condition occurs.
* @see dhcp_options_t
*/
-static int32_t
-dhcp_decode_options(uint8_t opt_field[], uint32_t opt_len,
- dhcp_options_t * opt_struct) {
- int32_t offset = 0;
+static int32_t dhcp_decode_options(uint8_t opt_field[], uint32_t opt_len,
+ dhcp_options_t * opt_struct)
+{
+ uint32_t offset = 0;
memset(opt_struct, 0, sizeof(dhcp_options_t));
switch(opt_field[offset]) {
case DHCP_OVERLOAD :
opt_struct -> overload = opt_field[offset + 2];
- offset += 2 + opt_field[offset + 1];
+ offset += 2 + opt_field[offset + 1];
break;
case DHCP_REQUESTED_IP :
opt_struct -> requested_IP = htonl(* (uint32_t *) (opt_field + offset + 2));
- offset += 2 + opt_field[offset + 1];
+ offset += 2 + opt_field[offset + 1];
break;
case DHCP_MASK :
opt_struct -> flag[DHCP_MASK] = 1;
opt_struct -> subnet_mask = htonl(* (uint32_t *) (opt_field + offset + 2));
- offset += 2 + opt_field[offset + 1];
+ offset += 2 + opt_field[offset + 1];
break;
case DHCP_DNS :
opt_struct -> flag[DHCP_DNS] = 1;
opt_struct -> dns_IP = htonl(* (uint32_t *) (opt_field + offset + 2));
- offset += 2 + opt_field[offset + 1];
+ offset += 2 + opt_field[offset + 1];
break;
case DHCP_ROUTER :
opt_struct -> flag[DHCP_ROUTER] = 1;
opt_struct -> router_IP = htonl(* (uint32_t *) (opt_field + offset + 2));
- offset += 2 + opt_field[offset + 1];
+ offset += 2 + opt_field[offset + 1];
break;
case DHCP_MSG_TYPE :
* FALSE - error condition occurs.
*/
static int8_t dhcp_merge_options(uint8_t dst_options[], uint32_t * dst_len,
- uint8_t src_options[], uint32_t src_len) {
- int32_t dst_offset, src_offset = 0;
+ uint8_t src_options[], uint32_t src_len)
+{
+ uint32_t dst_offset, src_offset = 0;
// remove ENDOPT if presented
- if (dhcp_find_option(dst_options, * dst_len, DHCP_ENDOPT, (uint32_t *) &dst_offset))
+ if (dhcp_find_option(dst_options, * dst_len, DHCP_ENDOPT, &dst_offset))
* dst_len = dst_offset;
while (src_offset < src_len) {
default:
if (dhcp_find_option(dst_options, * dst_len,
src_options[src_offset],
- (uint32_t *) &dst_offset)) {
+ &dst_offset)) {
dhcp_combine_option(dst_options, dst_len,
dst_offset,
(uint8_t *) src_options +
}
}
- if (src_offset == src_len)
+ if (src_offset == src_len)
return 1;
return 0;
}
* FALSE - option wasn't find.
*/
static int8_t dhcp_find_option(uint8_t options[], uint32_t len,
- uint8_t op_code, uint32_t * op_offset) {
+ uint8_t op_code, uint32_t * op_offset)
+{
uint32_t srch_offset = 0;
* op_offset = 0;
* @param dst_len length of the "options" field (modified)
* @param new_option points to an option in another list (src)
*/
-static void
-dhcp_append_option(uint8_t dst_options[], uint32_t * dst_len,
- uint8_t * new_option) {
+static void dhcp_append_option(uint8_t dst_options[], uint32_t * dst_len,
+ uint8_t * new_option)
+{
memcpy(dst_options + ( * dst_len), new_option, 2 + (* (new_option + 1)));
* dst_len += 2 + *(new_option + 1);
}
* @param dst_offset offset of the option from beginning of the list
* @param new_option points to an option in another list (src)
*/
-static void
-dhcp_combine_option(uint8_t dst_options[], uint32_t * dst_len,
- uint32_t dst_offset, uint8_t * new_option) {
-
+static void dhcp_combine_option(uint8_t dst_options[], uint32_t * dst_len,
+ uint32_t dst_offset, uint8_t * new_option)
+{
uint8_t tmp_buffer[1024]; // use to provide safe memcpy
uint32_t tail_len;
/**
* DHCP: Sends DHCP-Discover message. Looks for DHCP servers.
*/
-static void
-dhcp_send_discover(int fd) {
+static void dhcp_send_discover(int fd)
+{
uint32_t packetsize = sizeof(struct iphdr) +
sizeof(struct udphdr) + sizeof(struct btphdr);
struct btphdr *btph;
btph -> op = 1;
btph -> htype = 1;
btph -> hlen = 6;
+ btph -> xid = dhcp_xid;
memcpy(btph -> chaddr, get_mac_address(), 6);
memset(&opt, 0, sizeof(dhcp_options_t));
/**
* DHCP: Sends DHCP-Request message. Asks for acknowledgment to occupy IP.
*/
-static void
-dhcp_send_request(int fd) {
+static void dhcp_send_request(int fd)
+{
uint32_t packetsize = sizeof(struct iphdr) +
sizeof(struct udphdr) + sizeof(struct btphdr);
struct btphdr *btph;
btph -> op = 1;
btph -> htype = 1;
btph -> hlen = 6;
+ btph -> xid = dhcp_xid;
memcpy(btph -> chaddr, get_mac_address(), 6);
memset(&opt, 0, sizeof(dhcp_options_t));
/**
* DHCP: Sends DHCP-Release message. Releases occupied IP.
*/
-void dhcp_send_release(int fd) {
+void dhcp_send_release(int fd)
+{
uint32_t packetsize = sizeof(struct iphdr) +
sizeof(struct udphdr) + sizeof(struct btphdr);
struct btphdr *btph;
btph -> op = 1;
btph -> htype = 1;
btph -> hlen = 6;
+ btph -> xid = dhcp_xid;
strcpy((char *) btph -> file, "");
memcpy(btph -> chaddr, get_mac_address(), 6);
btph -> ciaddr = htonl(dhcp_own_ip);
dhcp_encode_options(btph -> vend, &opt);
- fill_udphdr(ðer_packet[sizeof(struct iphdr)],
+ fill_udphdr(ðer_packet[sizeof(struct iphdr)],
sizeof(struct btphdr) + sizeof(struct udphdr),
UDPPORT_BOOTPC, UDPPORT_BOOTPS);
fill_iphdr(ether_packet, sizeof(struct btphdr) +
* @see btphdr
*/
-int8_t
-handle_dhcp(int fd, uint8_t * packet, int32_t packetsize) {
+int8_t handle_dhcp(int fd, uint8_t * packet, int32_t packetsize)
+{
struct btphdr * btph;
struct iphdr * iph;
dhcp_options_t opt;
- memset(&opt, 0, sizeof(dhcp_options_t));
+ memset(&opt, 0, sizeof(dhcp_options_t));
btph = (struct btphdr *) packet;
iph = (struct iphdr *) packet - sizeof(struct udphdr) -
sizeof(struct iphdr);
- if (btph -> op != 2)
- return -1; // it is not Boot Reply
+
+ if (btph->op != 2)
+ return -1; /* It is not a Bootp/DHCP reply */
+ if (btph->xid != dhcp_xid)
+ return -1; /* The transaction ID does not match */
if (memcmp(btph -> vend, dhcp_magic, 4)) {
// It is BootP - RFC 951
}
- // decode options
+ // decode options
if (!dhcp_decode_options(btph -> vend, packetsize -
sizeof(struct btphdr) + sizeof(btph -> vend),
&opt)) {
else {
strcpy((char *) dhcp_filename, "");
if (opt.overload != DHCP_OVERLOAD_FILE &&
- opt.overload != DHCP_OVERLOAD_BOTH &&
+ opt.overload != DHCP_OVERLOAD_BOTH &&
strlen((char *) btph -> file)) {
strncpy((char *) dhcp_filename,
(char *) btph->file,
return 0;
}
-
-/**
- * DHCP: Converts "255.255.255.255" -> 32-bit long IP
- *
- * @param str string to be converted
- * @param ip in case of SUCCESS - 32-bit long IP
- in case of FAULT - zero
- * @return TRUE - IP converted successfully;
- * FALSE - error condition occurs (e.g. bad format)
- */
-static uint8_t
-strtoip(int8_t * str, uint32_t * ip) {
- int8_t ** ptr = &str;
- int16_t i = 0, res, len;
- char octet[256];
-
- * ip = 0;
-
- while (**ptr != 0) {
- if (i > 3 || !isdigit(**ptr))
- return 0;
- if (strstr((char *) * ptr, ".") != NULL) {
- len = (int16_t) ((int8_t *) strstr((char *) * ptr, ".") -
- (int8_t *) (* ptr));
- strncpy(octet, (char *) * ptr, len); octet[len] = 0;
- * ptr += len;
- }
- else {
- strcpy(octet, (char *) * ptr);
- * ptr += strlen(octet);
- }
- res = strtol(octet, NULL, 10);
- if ((res > 255) || (res < 0))
- return 0;
- * ip = ((* ip) << 8) + res;
- i++;
- if (** ptr == '.')
- (*ptr)++;
- }
-
- if (i != 4)
- return 0;
- return 1;
-}
Code Review / kvmfornfv.git / blobdiff