8 files changed, 181 insertions, 0 deletions

diff --git a/Semestr 4/sieci/pracownia1/icmp_checksum.c b/Semestr 4/sieci/pracownia1/icmp_checksum.c
new file mode 100644
index 0000000..c9dc96b
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/icmp_checksum.c
@@ -0,0 +1,10 @@
+u_int16_t compute_icmp_checksum (const void *buff, int length)
+{
+	u_int32_t sum;
+	const u_int16_t* ptr = buff;
+	assert (length % 2 == 0);
+	for (sum = 0; length > 0; length -= 2)
+		sum += *ptr++;
+	sum = (sum >> 16) + (sum & 0xffff);
+	return (u_int16_t)(~(sum + (sum >> 16)));
+}
diff --git a/Semestr 4/sieci/pracownia1/icmp_receive.c b/Semestr 4/sieci/pracownia1/icmp_receive.c
new file mode 100644
index 0000000..07d3b69
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/icmp_receive.c
@@ -0,0 +1,53 @@
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+
+void print_as_bytes (unsigned char* buff, ssize_t length)
+{
+	for (ssize_t i = 0; i < length; i++, buff++)
+		printf ("%.2x ", *buff);	
+}
+
+
+int main()
+{
+	int sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+	if (sockfd < 0) {
+		fprintf(stderr, "socket error: %s\n", strerror(errno)); 
+		return EXIT_FAILURE;
+	}
+
+	for (;;) {
+		
+		struct sockaddr_in 	sender;	
+		socklen_t 			sender_len = sizeof(sender);
+		u_int8_t 			buffer[IP_MAXPACKET];
+
+		ssize_t packet_len = recvfrom (sockfd, buffer, IP_MAXPACKET, 0, (struct sockaddr*)&sender, &sender_len);
+		if (packet_len < 0) {
+			fprintf(stderr, "recvfrom error: %s\n", strerror(errno)); 
+			return EXIT_FAILURE;
+		}
+
+		char sender_ip_str[20]; 
+		inet_ntop(AF_INET, &(sender.sin_addr), sender_ip_str, sizeof(sender_ip_str));
+		printf ("Received IP packet with ICMP content from: %s\n", sender_ip_str);
+
+		struct ip* 			ip_header = (struct ip*) buffer;
+		ssize_t				ip_header_len = 4 * ip_header->ip_hl;
+
+		printf ("IP header: "); 
+		print_as_bytes (buffer, ip_header_len);
+		printf("\n");
+
+		printf ("IP data:   ");
+		print_as_bytes (buffer + ip_header_len, packet_len - ip_header_len);
+		printf("\n\n");
+	}
+
+	return EXIT_SUCCESS;
+}
diff --git a/Semestr 4/sieci/pracownia1/makefile b/Semestr 4/sieci/pracownia1/makefile
new file mode 100644
index 0000000..63f9518
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/makefile
@@ -0,0 +1,12 @@
+CC=gcc
+CFLAGS=-g -Wall -Wextra -Wshadow -pedantic -fsanitize=address -fsanitize=undefined
+
+TARGET=traceroute
+
+all: $(TARGET)
+
+$(TARGET): $(TARGET).c
+	$(CC) $(CFLAGS) -o $(TARGET) $(TARGET).c
+
+clean:
+	$(RM) $(TARGET)
\ No newline at end of file
diff --git a/Semestr 4/sieci/pracownia1/p1.pdf b/Semestr 4/sieci/pracownia1/p1.pdf
new file mode 100644
index 0000000..4b06555
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/p1.pdf
diff --git a/Semestr 4/sieci/pracownia1/traceroute.c b/Semestr 4/sieci/pracownia1/traceroute.c
new file mode 100644
index 0000000..7918957
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/traceroute.c
@@ -0,0 +1,106 @@
+#include <stdio.h>
+#include <errno.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+#include <strings.h>
+#include <string.h>
+#include <stdlib.h>
+#include <netinet/ip_icmp.h>
+#include <assert.h>
+
+#define MAX_TTL 30
+#define MESSAGES_PER_TTL 3
+
+void print_as_bytes (unsigned char* buff, ssize_t length)
+{
+	for (ssize_t i = 0; i < length; i++, buff++)
+		printf ("%.2x ", *buff);	
+}
+
+struct sockaddr_in get_sockaddr_from_ip(char *ip) {
+    struct sockaddr_in sock;
+    bzero(&sock, sizeof(sock));
+    sock.sin_family = AF_INET;
+    if (!inet_pton(AF_INET, ip, &sock.sin_addr)) {
+        fprintf(stderr, "Given ip is invalid: %s\n", ip);
+        exit(EXIT_FAILURE);
+    }
+    return sock;
+}
+
+int create_raw_icmp_socket() {
+    int sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
+    if (sockfd < 0) {
+        fprintf(stderr, "socket error: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    return sockfd;
+}
+
+uint16_t compute_icmp_checksum (const void *buff, int length)
+{
+	uint32_t sum;
+	const uint16_t* ptr = buff;
+	assert (length % 2 == 0);
+	for (sum = 0; length > 0; length -= 2)
+		sum += *ptr++;
+	sum = (sum >> 16) + (sum & 0xffff);
+	return (uint16_t)(~(sum + (sum >> 16)));
+}
+
+struct icmp create_icmp_header() {
+    static uint16_t pid = 0;
+    static uint16_t seq = 0;
+    
+    struct icmp header;
+    header.icmp_type = ICMP_ECHO;
+    header.icmp_code = 0;
+    header.icmp_id = ++pid;
+    header.icmp_seq = ++seq;
+    header.icmp_cksum = 0;
+    header.icmp_cksum = compute_icmp_checksum(
+        (uint16_t*)&header, sizeof(header));
+
+    return header;
+}
+
+void send_icmp_packet(int sockfd, struct sockaddr_in *destination, int ttl) {
+    struct icmp header = create_icmp_header();
+    setsockopt(sockfd, IPPROTO_IP, IP_TTL, &ttl, sizeof(int));
+
+    printf("%ld %d\n", destination->sin_addr.s_addr, sockfd);
+    ssize_t bytes_sent = sendto(
+        sockfd,
+        &header,
+        sizeof(header),
+        0,
+        (struct sockaddr*)destination,
+        sizeof(*destination)
+    );
+    if (bytes_sent == -1) {
+        fprintf(stderr, "Error while sending ICMP packet: %s\n", strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+    fprintf(stdout, "Bytes sent: %ld\n", bytes_sent);
+}
+
+int traceroute(struct sockaddr_in *destination) {
+    int sockfd = create_raw_icmp_socket();
+
+    struct sockaddr_in  sender;
+    socklen_t           sender_len = sizeof(sender);
+    uint8_t             buffer[IP_MAXPACKET];
+    for (int ttl = 1; ttl <= MAX_TTL; ++ttl) {
+        send_icmp_packet(sockfd, destination, ttl);
+    }
+}     
+
+int main(int argc, char * argv[]) {
+    if (argc < 2) {
+        fprintf(stderr, "Usage:\n\t%s [host ip]\n", argv[0]);
+        return 1;
+    }
+
+    struct sockaddr_in destination = get_sockaddr_from_ip(argv[1]);
+    traceroute(&destination);
+}
\ No newline at end of file
diff --git a/Semestr 4/sieci/warsztaty2/w2.pdf b/Semestr 4/sieci/warsztaty2/w2.pdf
new file mode 100644
index 0000000..60cdc33
--- /dev/null
+++ b/Semestr 4/sieci/warsztaty2/w2.pdf
diff --git a/Semestr 4/sieci/wyklady/lec1.pdf b/Semestr 4/sieci/wyklady/lec1.pdf
new file mode 100644
index 0000000..5da8f03
--- /dev/null
+++ b/Semestr 4/sieci/wyklady/lec1.pdf
diff --git a/Semestr 4/sieci/wyklady/lec2.pdf b/Semestr 4/sieci/wyklady/lec2.pdf
new file mode 100644
index 0000000..edb1398
--- /dev/null
+++ b/Semestr 4/sieci/wyklady/lec2.pdf