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authorFranciszek Malinka <franciszek.malinka@gmail.com>2021-04-19 18:05:41 +0200
committerFranciszek Malinka <franciszek.malinka@gmail.com>2021-04-19 18:05:41 +0200
commit9247a4c0998de14ef5993822cac75b4a6327ee1e (patch)
tree50ebb7e1db657a70b6309265661fb5cf6dfd49ff /Semestr 4/sieci/pracownia2
parentbf9914308497839c1d05905f6f156ee4165fdae1 (diff)
Router working finally
Diffstat (limited to 'Semestr 4/sieci/pracownia2')
-rw-r--r--Semestr 4/sieci/pracownia2/router/config.h6
-rw-r--r--Semestr 4/sieci/pracownia2/router/dist_vector.c99
-rw-r--r--Semestr 4/sieci/pracownia2/router/dist_vector.h18
-rw-r--r--Semestr 4/sieci/pracownia2/router/linked_list.c5
-rw-r--r--Semestr 4/sieci/pracownia2/router/linked_list.h2
-rw-r--r--Semestr 4/sieci/pracownia2/router/network_addr.c22
-rw-r--r--Semestr 4/sieci/pracownia2/router/network_addr.h10
-rw-r--r--Semestr 4/sieci/pracownia2/router/router.c74
-rw-r--r--Semestr 4/sieci/pracownia2/router/utils.c132
-rw-r--r--Semestr 4/sieci/pracownia2/router/utils.h13
10 files changed, 295 insertions, 86 deletions
diff --git a/Semestr 4/sieci/pracownia2/router/config.h b/Semestr 4/sieci/pracownia2/router/config.h
index 3537c03..ef8bf47 100644
--- a/Semestr 4/sieci/pracownia2/router/config.h
+++ b/Semestr 4/sieci/pracownia2/router/config.h
@@ -3,6 +3,12 @@
#define SERVER_PORT 54321
#define TURN_LEN_S 5
+
+#define INFINITY_DIST 16
+#define REACHABILITY_WAIT_TIME 5
+
+#define DV_DATAGRAM_LEN 9
+
#define TURN_LEN_MS (1000 * TURN_LEN_S)
#define TURN_LEN_US (1000000 * TURN_LEN_S)
diff --git a/Semestr 4/sieci/pracownia2/router/dist_vector.c b/Semestr 4/sieci/pracownia2/router/dist_vector.c
index 1e09bff..f1c8c67 100644
--- a/Semestr 4/sieci/pracownia2/router/dist_vector.c
+++ b/Semestr 4/sieci/pracownia2/router/dist_vector.c
@@ -1,8 +1,101 @@
#include "dist_vector.h"
+#include <stdio.h>
bool is_connected_directly(struct vector_item item) {
- return (get_network_address(item.network).s_addr ==
- get_network_address(item.via_ip).s_addr);
+ return item.is_connected_directly;
}
-void update_distance_vector(list_t *distance_vector, struct vector_item new_item) {} \ No newline at end of file
+bool is_reachable(struct vector_item item) {
+ return (item.distance < INFINITY_DIST);
+}
+
+void init_dv(list_t *dv, int n_cnt, struct network_addr *neighbours) {
+ for (int i = 0; i < n_cnt; i++) {
+ struct vector_item new_item;
+ new_item.network = neighbours[i];
+ new_item.distance = INFINITY_DIST;
+ new_item.is_connected_directly = true;
+ insert(dv, &new_item, sizeof(new_item));
+ }
+}
+
+void update_dv_reachability(list_t *distance_vector) {
+ reset(distance_vector);
+ while (distance_vector->it != NULL) {
+ struct vector_item *current = (struct vector_item *)distance_vector->it->data;
+ if(++current->reachable > REACHABILITY_WAIT_TIME) {
+ if (current->distance >= INFINITY_DIST) {
+ if (!is_connected_directly(*current)) {
+ erase_it(distance_vector);
+ }
+ } else {
+ current->distance = INFINITY_DIST;
+ current->reachable = 0;
+ }
+ }
+ iterate(distance_vector);
+ }
+}
+
+void update_dv_new_item(list_t *distance_vector, struct vector_item new_item) {
+ bool new_entry = true;
+ reset(distance_vector);
+ while (distance_vector->it != NULL) {
+ struct vector_item *current = (struct vector_item *)distance_vector->it->data;
+
+ /* If the network is already in the distance vector, then we possibly want to change it:
+ * - if the new item has better distance than the previous one, then we just want to change it no matter what,
+ * - if the new item has the same via ip, then we want to check two things:
+ * - if new item has infinity dist, then we want to set infinity (if it wasn't set, then we want to change reachable to 0)
+ * - if new item has < inf dist, then we want to change reachable to 0 and set our dist accordingly.
+ * - else we ignore the entry.
+ */
+ if (get_network_address(current->network).s_addr == get_network_address(new_item.network).s_addr) {
+ if (current->distance > new_item.distance) {
+ *current = new_item;
+ current->reachable = 0;
+ } else if(current->via_ip.s_addr == new_item.via_ip.s_addr) {
+ if (new_item.distance >= INFINITY_DIST) {
+ if (current->distance < INFINITY_DIST) {
+ current->distance = INFINITY_DIST;
+ current->reachable = 0;
+ }
+ } else if (new_item.distance < INFINITY_DIST) {
+ if (current->distance >= INFINITY_DIST) {
+ current->distance = new_item.distance;
+ }
+ current->reachable = 0;
+ }
+ }
+ new_entry = false;
+ }
+
+ iterate(distance_vector);
+ }
+
+ if (new_entry) {
+ insert(distance_vector, &new_item, sizeof(new_item));
+ }
+}
+
+void print_dv(list_t *distance_vector) {
+ printf("Distance vector:\n");
+ reset(distance_vector);
+ while (distance_vector->it != NULL) {
+ char addr[20], via_addr[20];
+ struct vector_item current = *(struct vector_item *)distance_vector->it->data;
+ struct in_addr net_addr = get_network_address(current.network);
+ inet_ntop(AF_INET, &net_addr, addr, sizeof(addr));
+ printf("%s/%d ", addr, current.network.netmask);
+
+ if (is_reachable(current)) printf("distance %d ", current.distance);
+ else printf("unreachable ");
+
+ inet_ntop(AF_INET, &current.via_ip, via_addr, sizeof(via_addr));
+ if (is_connected_directly(current)) printf("connected directly\n");
+ else printf("via %s\n", via_addr);
+
+ iterate(distance_vector);
+ }
+ printf("\n");
+} \ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia2/router/dist_vector.h b/Semestr 4/sieci/pracownia2/router/dist_vector.h
index cd1a995..14159b4 100644
--- a/Semestr 4/sieci/pracownia2/router/dist_vector.h
+++ b/Semestr 4/sieci/pracownia2/router/dist_vector.h
@@ -3,6 +3,7 @@
#include "linked_list.h"
#include "network_addr.h"
+#include "config.h"
/* Item of the distance vector.
* If <<reachable>> is set to 0, then it means that the network is reachable.
@@ -11,14 +12,25 @@
*/
struct vector_item {
struct network_addr network;
- router_addr via_ip;
+ struct in_addr via_ip;
+ uint16_t distance;
uint8_t reachable;
+ bool is_connected_directly;
};
-/* Returns true if given distance vector item is connected directly, false otherwise */
+/* Initis distance vector with given neighbours array. */
+void init_dv(list_t *dv, int n_cnt, struct network_addr *neighbours);
+
+/* Returns true if given distance vector item is connected directly, false otherwise. */
bool is_connected_directly(struct vector_item item);
/* Updates the distance vector. */
-void update_distance_vector(list_t *distance_vector, struct vector_item new_item);
+void update_dv_new_item(list_t *distance_vector, struct vector_item new_item);
+
+/* Updates reachabilities. */
+void update_dv_reachability(list_t *distance_vector);
+
+/* Print distance vector. */
+void print_dv(list_t *distance_vector);
#endif \ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia2/router/linked_list.c b/Semestr 4/sieci/pracownia2/router/linked_list.c
index f3bccc9..09f6025 100644
--- a/Semestr 4/sieci/pracownia2/router/linked_list.c
+++ b/Semestr 4/sieci/pracownia2/router/linked_list.c
@@ -8,10 +8,7 @@ node_t *_next(node_t *node) {
void _insert(node_t **head, void *data, size_t data_size) {
node_t *new_node = (node_t *)malloc(sizeof(node_t));
- new_node->data = malloc(data_size);
- for (int i = 0; i < data_size; i++)
- *(uint8_t *)(new_node->data + i) = *(uint8_t *)(data + i);
-
+ new_node->data = malloc(data_size);
new_node->next = *head;
*head = new_node;
}
diff --git a/Semestr 4/sieci/pracownia2/router/linked_list.h b/Semestr 4/sieci/pracownia2/router/linked_list.h
index 28e8ef7..1574b2f 100644
--- a/Semestr 4/sieci/pracownia2/router/linked_list.h
+++ b/Semestr 4/sieci/pracownia2/router/linked_list.h
@@ -15,7 +15,7 @@ typedef struct list_t {
node_t *prev_it;
} list_t;
-/* Creates an empty list */
+/* Creates an empty list. */
list_t create_list();
/* Insert a new node in the begining of a list. */
diff --git a/Semestr 4/sieci/pracownia2/router/network_addr.c b/Semestr 4/sieci/pracownia2/router/network_addr.c
index a65f48c..d1982c2 100644
--- a/Semestr 4/sieci/pracownia2/router/network_addr.c
+++ b/Semestr 4/sieci/pracownia2/router/network_addr.c
@@ -5,21 +5,31 @@
struct in_addr _get_broadcast_address(struct in_addr addr, uint16_t netmask) {
struct in_addr result = addr;
+ result.s_addr = ntohl(result.s_addr);
/* bitshift by more than 31 is UB */
- if (netmask < 32) {
- result.s_addr |= ~((1<<netmask) - 1);
+ if (netmask == 0) {
+ result.s_addr = -1;
+ }
+ else {
+ result.s_addr |= ((1 << (32 - netmask)) - 1);
}
+ result.s_addr = htonl(result.s_addr);
+
return result;
}
struct in_addr _get_network_address(struct in_addr addr, uint16_t netmask) {
struct in_addr result = addr;
+ result.s_addr = ntohl(result.s_addr);
+
if (netmask == 0) {
- addr.s_addr = 0;
+ result.s_addr = 0;
}
else {
result.s_addr &= ~((1 << (32 - netmask)) - 1);
}
+ result.s_addr = htonl(result.s_addr);
+
return result;
}
@@ -31,13 +41,13 @@ struct in_addr get_network_address(struct network_addr na) {
return _get_network_address(na.addr, na.netmask);
}
-void pretty_print(struct network_addr na) {
+void pretty_print_network(struct network_addr na) {
char ip_addr[20];
inet_ntop(AF_INET, &na.addr, ip_addr, sizeof(ip_addr));
- printf("%s/%d distance %d\n", ip_addr, na.netmask, na.distance);
+ printf("%s/%d\n", ip_addr, na.netmask);
}
-struct network_addr stora(char *str) {
+struct network_addr stona(char *str) {
struct network_addr result;
char addr[20];
size_t ip_preffix = strcspn(str, "/");
diff --git a/Semestr 4/sieci/pracownia2/router/network_addr.h b/Semestr 4/sieci/pracownia2/router/network_addr.h
index 2067e05..616c64f 100644
--- a/Semestr 4/sieci/pracownia2/router/network_addr.h
+++ b/Semestr 4/sieci/pracownia2/router/network_addr.h
@@ -5,12 +5,9 @@
#include <stdint.h>
#include <stdbool.h>
-#define INFINITY_DIST 128
-
-/* Network address and sitance */
+/* Network address with netmask. */
struct network_addr {
struct in_addr addr;
- uint16_t distance;
uint8_t netmask;
};
@@ -23,10 +20,9 @@ struct in_addr get_broadcast_address(struct network_addr na);
struct in_addr get_network_address(struct network_addr na);
/* Prints network_addr via stdio. */
-void pretty_print(struct network_addr na);
+void pretty_print_network(struct network_addr na);
/* Converts string of ip in CIDR notation with a netmask to network_addr. */
-struct network_addr stora(char *str);
-
+struct network_addr stona(char *str);
#endif \ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia2/router/router.c b/Semestr 4/sieci/pracownia2/router/router.c
index 031ead8..7262ee6 100644
--- a/Semestr 4/sieci/pracownia2/router/router.c
+++ b/Semestr 4/sieci/pracownia2/router/router.c
@@ -7,74 +7,78 @@
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
+#include <limits.h>
#include "network_addr.h"
#include "utils.h"
+#include "dist_vector.h"
-uint16_t read_configuration(struct network_addr** networks) {
+uint16_t read_configuration(struct network_addr** networks, uint16_t **dists) {
uint16_t n;
scanf("%hd", &n);
*networks = malloc(n * sizeof(struct network_addr));
+ *dists = malloc(n * sizeof(uint16_t));
for (int i = 0; i < n; i++) {
char addr[20];
char _dist[10];
uint16_t dist;
scanf(" %s %s %hd", addr, _dist, &dist);
- (*networks)[i] = stora(addr);
- (*networks)[i].distance = dist;
+ (*networks)[i] = stona(addr);
+ (*dists)[i] = dist;
}
return n;
}
-void listen_for_routers(int sockfd, int timeout, int networks_number, struct network_addr *netowrks) {
- printf("Listening for %dms.\n", timeout);
+void listen_for_routers(int sockfd, int timeout, int networks_number, struct network_addr *networks, uint16_t *dists, list_t *dv) {
+ // printf("Listening for %dms.\n", timeout);
+ char buffer[IP_MAXPACKET + 1];
+ struct sockaddr_in sender;
+
while (poll_socket_modify_timeout(sockfd, &timeout)) {
- printf("Poll returned, remaining timeout: %dms.\n", timeout);
- recv_and_print(sockfd, networks_number, netowrks);
- }
- printf("Finished listening\n\n");
-}
+ size_t buf_len = recv_message(sockfd, buffer, &sender);
+ struct vector_item new_item = parse_message(buffer, &sender);
+ // char addr[20];
+ // inet_ntop(AF_INET, &sender.sin_addr, addr, sizeof(addr));
+ // printf("Via ip: %s\n", addr);
-int send_distance_vector(int sockfd, struct in_addr network) {
- char* message = "Hello server! My name is S1\n";
- ssize_t message_len = strlen(message);
- int result;
+ if (!is_from_network(sender.sin_addr, new_item.network)) {
+ for (int i = 0; i < networks_number; i++) {
+ if (is_from_network(sender.sin_addr, networks[i])) {
+ new_item.distance += dists[i];
+ break;
+ }
+ }
+ new_item.is_connected_directly = false;
+ }
- char addr[20];
- inet_ntop(AF_INET, &network, addr, sizeof(addr));
- printf("Sending datagram to %s\n", addr);
- if ((result = send_message(sockfd, message, message_len, network)) != message_len) {
- fprintf(stderr, "sendto error: %s\n", strerror(errno));
+ update_dv_new_item(dv, new_item);
}
+ update_dv_reachability(dv);
+ // printf("Finished listening\n\n");
}
-void propagate_distance_vector(int sockfd, int networks_number, struct network_addr *networks) {
- printf("Propagating distance vector\n");
- for (int i = 0; i < networks_number; i++) {
- struct in_addr broadcast_address = get_broadcast_address(networks[i]);
- send_distance_vector(sockfd, broadcast_address);
- }
- printf("Distance vector propagated.\n\n");
-}
+void router_loop(int sockfd, int networks_number, struct network_addr *networks, uint16_t *dists) {
+ list_t dv = create_list();
+ init_dv(&dv, networks_number, networks);
-void router_loop(int sockfd, int networks_number, struct network_addr *networks) {
printf("Starting the router loop...\n");
for (;;) {
- listen_for_routers(sockfd, TURN_LEN_MS, networks_number, networks);
- propagate_distance_vector(sockfd, networks_number, networks);
+ print_dv(&dv);
+ propagate_distance_vector(sockfd, networks_number, networks, dists, &dv);
+ listen_for_routers(sockfd, TURN_LEN_MS, networks_number, networks, dists, &dv);
}
}
int main() {
struct network_addr* networks;
- int n = read_configuration(&networks);
- for (int i = 0; i < n; i++) {
- pretty_print(networks[i]);
- }
+ uint16_t *dists;
+ int n = read_configuration(&networks, &dists);
int sockfd = get_socket();
bind_to_port(sockfd, SERVER_PORT);
- router_loop(sockfd, n, networks);
+
+ router_loop(sockfd, n, networks, dists);
close(sockfd);
free(networks);
+ free(dists);
} \ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia2/router/utils.c b/Semestr 4/sieci/pracownia2/router/utils.c
index 2872a35..3f9078e 100644
--- a/Semestr 4/sieci/pracownia2/router/utils.c
+++ b/Semestr 4/sieci/pracownia2/router/utils.c
@@ -5,6 +5,7 @@
#include <errno.h>
#include <stdio.h>
#include <string.h>
+#include <limits.h>
int get_socket() {
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
@@ -37,7 +38,7 @@ long get_time_interval(struct timespec start, struct timespec finish) {
int poll_socket_modify_timeout(int sockfd, int *timeout) {
if (*timeout < 0) {
- fprintf(stderr, "poll_modify_timeout: timeout is negative.\n");
+ fprintf(stderr, "poll_socket_modify_timeout: timeout is negative.\n");
exit(EXIT_FAILURE);
}
@@ -62,35 +63,9 @@ int poll_socket_modify_timeout(int sockfd, int *timeout) {
clock_gettime(CLOCK_REALTIME, &finish);
*timeout -= get_time_interval(start, finish);
- printf("Timeout: %dms, time waiting: %ldms.\n", *timeout, get_time_interval(start, finish));
return result;
}
-void recv_and_print(int sockfd, int networks_number, struct network_addr *networks) {
- struct sockaddr_in sender;
- socklen_t sender_len = sizeof(sender);
- uint8_t buffer[IP_MAXPACKET + 1];
- ssize_t datagram_len = recvfrom(sockfd, buffer, IP_MAXPACKET, 0,
- (struct sockaddr*)&sender, &sender_len);
- if (datagram_len < 0) {
- fprintf(stderr, "recvfrom error: %s\n", strerror(errno));
- exit(EXIT_FAILURE);
- }
- for (int i = 0; i < networks_number; i++) {
- if (networks[i].addr.s_addr == sender.sin_addr.s_addr) {
- return;
- }
- }
-
- char sender_ip_str[20];
- inet_ntop(AF_INET, &(sender.sin_addr), sender_ip_str, sizeof(sender_ip_str));
- printf("Received UDP packet from IP address: %s, port %d\n",
- sender_ip_str, ntohs(sender.sin_port));
-
- buffer[datagram_len] = 0;
- printf("%ld-byte message: +%s+\n", datagram_len, buffer);
-}
-
size_t send_message(int sockfd, char *buffer, int buffer_len, struct in_addr network) {
struct sockaddr_in network_address;
bzero (&network_address, sizeof(network_address));
@@ -100,3 +75,106 @@ size_t send_message(int sockfd, char *buffer, int buffer_len, struct in_addr net
return sendto(sockfd, buffer, buffer_len, 0, (struct sockaddr*) &network_address, sizeof(network_address));
}
+
+size_t recv_message(int sockfd, char *buffer, struct sockaddr_in *sender) {
+ socklen_t sender_len = sizeof(*sender);
+ for (int i = 0; i < DV_DATAGRAM_LEN; i++) buffer[i] = 0;
+ size_t datagram_len = recvfrom(sockfd, buffer, IP_MAXPACKET, 0,
+ (struct sockaddr*)sender, &sender_len);
+ if (datagram_len < 0) {
+ fprintf(stderr, "recvfrom error: %s\n", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+ // printf("Received a message: ");
+ // for (int i = 0 ; i < 9; i++) {
+ // printf("%u ", (uint8_t)buffer[i]);
+ // }
+ // printf("\n");
+ return datagram_len;
+}
+
+struct vector_item parse_message(char *buffer, struct sockaddr_in *sender) {
+ // printf("Parsing a message: ");
+ // for (int i = 0 ; i < 9; i++) {
+ // printf("%u ", (uint8_t)buffer[i]);
+ // }
+ // printf("\n");
+ struct vector_item res;
+ uint32_t ip_addr = *(uint32_t *)buffer;
+ // ip_addr = ip_addr;
+ uint32_t dist = *(uint32_t *)(buffer + 5);
+ dist = ntohl(dist);
+
+ res.network.addr.s_addr = ip_addr;
+ res.network.netmask = buffer[4];
+ res.is_connected_directly = true;
+ res.via_ip = sender->sin_addr;
+ res.distance = (dist < INFINITY_DIST ? dist : INFINITY_DIST);
+ res.reachable = 0;
+
+ char addr[20];
+ inet_ntop(AF_INET, &res.network.addr, addr, sizeof(addr));
+ char via[20];
+ inet_ntop(AF_INET, &sender->sin_addr, via, sizeof(via));
+
+ // printf("Po ludzku: %s/%d, distance %d, via %s\n", addr, res.network.netmask, res.distance, via);
+
+ return res;
+}
+
+void _get_message(struct vector_item item, char *message) {
+ *(uint32_t *)message = item.network.addr.s_addr;
+ message[4] = item.network.netmask;
+ uint32_t distance = htonl(item.distance >= INFINITY_DIST ? INT_MAX : item.distance);
+ for (int i = 0; i < 4; i++) {
+ *(message + 5 + i) = *((char *)(&distance) + i);
+ }
+}
+
+int _send_item(int sockfd, struct network_addr network, struct vector_item item) {
+ char message[DV_DATAGRAM_LEN + 1];
+ _get_message(item, message);
+ message[DV_DATAGRAM_LEN] = 0;
+ ssize_t message_len = DV_DATAGRAM_LEN;
+
+ struct in_addr na = get_broadcast_address(network);
+
+ char addr[20];
+ inet_ntop(AF_INET, &na, addr, sizeof(addr));
+ // printf("Sending datagram to %s: ", addr);
+ // for (int i = 0 ; i < DV_DATAGRAM_LEN; i++) {
+ // printf("%u ", (uint8_t)message[i]);
+ // }
+ // printf("\nmessage_len: %ld\n", message_len);
+ int result;
+ if ((result = send_message(sockfd, message, message_len, na)) != message_len) {
+ // fprintf(stderr, "sendto error: %s\n", strerror(errno));
+ }
+ return result;
+}
+
+void propagate_distance_vector(int sockfd, int networks_number, struct network_addr *networks, uint16_t *dists, list_t *dv) {
+ for (int i = 0; i < networks_number; i++) {
+ reset(dv);
+ while (dv->it != NULL) {
+ struct vector_item data = *(struct vector_item *)dv->it->data;
+ if (!(get_network_address(data.network).s_addr == get_network_address(networks[i]).s_addr)) {
+ _send_item(sockfd, networks[i], data);
+ }
+ iterate(dv);
+ }
+
+ struct vector_item self_item;
+ self_item.distance = dists[i];
+ self_item.network = networks[i];
+ // printf("Sending self message: %d\n", dists[i]);
+ _send_item(sockfd, networks[i], self_item);
+ }
+}
+
+bool is_from_network(struct in_addr ip_addr, struct network_addr network) {
+ struct network_addr temp;
+ temp.addr= ip_addr;
+ temp.netmask = network.netmask;
+ return (get_network_address(temp).s_addr == get_network_address(network).s_addr);
+} \ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia2/router/utils.h b/Semestr 4/sieci/pracownia2/router/utils.h
index 63ad6fb..3642779 100644
--- a/Semestr 4/sieci/pracownia2/router/utils.h
+++ b/Semestr 4/sieci/pracownia2/router/utils.h
@@ -7,6 +7,7 @@
#include <time.h>
#include <poll.h>
#include "network_addr.h"
+#include "dist_vector.h"
#define NS_TO_MS(X) ((long)(X) / (long)1000000)
#define S_TO_MS(X) ((long)(X) * (long)1000)
@@ -32,5 +33,17 @@ void recv_and_print(int sockfd, int networks_number, struct network_addr *networ
*/
size_t send_message(int sockfd, char *buffer, int buffer_len, struct in_addr addr);
+/* Receive message and write it to buffer. */
+size_t recv_message(int sockfd, char *buffer, struct sockaddr_in *sender);
+
+/* Parse datagram into a vector item. */
+struct vector_item parse_message(char *buffer, struct sockaddr_in *sender);
+
+/* Propagates dv to all connected networks. */
+void propagate_distance_vector(int sockfd, int networks_number, struct network_addr *networks, uint16_t *dists, list_t *dv);
+
+/* Checks if given address is in network range. */
+bool is_from_network(struct in_addr ip_addr, struct network_addr network);
+
#endif \ No newline at end of file