clean: split code in multiple files

src/dns.c

@@ -0,0 +1,36 @@
+
+
+#include "print.h"
+#include <arpa/inet.h>
+#include <stddef.h>
+#include <netdb.h>
+#include <strings.h>
+
+int dns_lookup(const char *hostname, char *ipstr)
+{
+    struct addrinfo filter;
+
+    bzero(&filter, sizeof(filter));
+    filter.ai_family = AF_INET; 
+
+    struct addrinfo *responses;
+    if (getaddrinfo(hostname, NULL, &filter, &responses) != 0)
+    {
+        print_err("dns lookup failed");
+        return 1;
+    }
+
+    struct addrinfo *first = responses;
+    struct in_addr *addr = &(((struct sockaddr_in *) responses->ai_addr)->sin_addr);
+    
+    inet_ntop(first->ai_family, addr, ipstr, sizeof(char) * INET_ADDRSTRLEN);
+
+    freeaddrinfo(responses);
+
+    return 0;
+}
+
+int dns_reverse_lookup(const char *ipstr, char *hostname);
+{
+
+}

src/dns.h

@@ -0,0 +1,4 @@
+#pragma once
+
+int dns_lookup(const char *hostname, char *ipstr);
+int dns_reverse_lookup(const char *ipstr, char *hostname);

src/main.c

@@ -1,3 +1,5 @@
+#include "packet.h"
+#include "print.h"
 #include <signal.h>
 #include <stddef.h>
 #include <stdint.h>
@@ -20,162 +22,12 @@
 
 bool loop = true;
 
-void print_err(const char *format, ...)
-{
-    va_list args;
-
-    puts("ft_ping: ");
-    va_start(args, format);
-    vprintf(format, args);
-    va_end(args);
-    putchar('\n');
-}
-
-unsigned short checksum(void *b, int len) {
-    unsigned short *buf = b;
-    unsigned int sum = 0;
-    unsigned short result;
-
-    for (sum = 0; len > 1; len -= 2)
-        sum += *buf++;
-    if (len == 1)
-        sum += *(unsigned char *)buf;
-    sum = (sum >> 16) + (sum & 0xFFFF);
-    sum += (sum >> 16);
-    result = ~sum;
-    return result;
-}
-
-int pktcmp(const char *sent, const char *received, size_t packet_size)
-{
-    const struct icmphdr *sent_hdr = (const struct icmphdr*) sent;
-    const struct icmphdr *received_hdr = (const struct icmphdr*) received;
-    
-    if (received_hdr->type != 0 || received_hdr->code != 8)
-        return 1;
-
-    if (received_hdr->un.echo.sequence == sent_hdr->un.echo.sequence)
-        return 2;
-
-    const char *sent_payload = sent + sizeof(struct icmphdr);
-    const char *received_payload = received + sizeof(struct icmphdr);
-
-    return memcmp(sent_payload, received_payload, packet_size - sizeof(struct icmphdr));
-}
-
-int fill_with_random(char *str, size_t nb)
-{
-    int fd;
-    
-    fd = open("/dev/random", O_RDONLY);
-    if (fd < 0)
-    {
-        print_err("error: open /dev/random failed.");
-        return 1;
-    }
-    if (read(fd, str, nb) != (ssize_t) nb)
-    {
-        close(fd);
-        print_err("error: read /dev/random failed.");
-        return 2;
-    }
-    close(fd);
-    return 0;
-}
-
-int update_packet(char *packet, size_t payload_size)
-{
-    static size_t sequence = 1;
-    size_t hdr_size = sizeof(struct icmphdr);
-    size_t packet_size = hdr_size + payload_size;
-
-    struct icmphdr *hdr = (void*)packet;
-
-    hdr->un.echo.sequence = htons(sequence++);
-    hdr->checksum = 0;
-
-    if (fill_with_random(packet + hdr_size, payload_size))
-    {
-        free(packet);
-        return 1;
-    }
-
-    hdr->checksum = checksum(packet, packet_size);
-    return 0;
-}
-
-void *create_packet(size_t payload_size)
-{
-    size_t hdr_size = sizeof(struct icmphdr);
-    size_t packet_size = hdr_size + payload_size;
-
-    char *packet;
-
-    packet = malloc(packet_size);
-    if (packet == NULL)
-    {
-        print_err("allocation failed.");
-        return NULL;
-    }
-
-    struct icmphdr *hdr = (struct icmphdr *)packet;
-
-    hdr->type = ICMP_ECHO;
-    hdr->code = 0;
-    hdr->un.echo.id = htons(getpid() & 0xFFFF);
-
-    update_packet(packet, payload_size);
-
-    return packet;
-}
-
-int packet_check(char *packet, size_t packet_size)
-{
-    struct icmphdr *hdr = (struct icmphdr *) packet;
-    
-    const uint16_t checksum_bak = hdr->checksum;
-    hdr->checksum = 0;
-    int tmp = checksum(packet, packet_size);
-    hdr->checksum = checksum_bak;
-
-    return tmp - checksum_bak;
-}
-
 void signal_handler(int code)
 {
     (void) code;
     loop = false;
 }
 
-char *dns_lookup(const char *hostname)
-{
-    char *ipstr = malloc(sizeof(char) * INET_ADDRSTRLEN);
-    if (ipstr == NULL)
-        return NULL;
-
-    struct addrinfo filter;
-
-    bzero(&filter, sizeof(filter));
-    filter.ai_family = AF_INET; 
-
-    struct addrinfo *responses;
-    if (getaddrinfo(hostname, NULL, &filter, &responses) != 0)
-    {
-        print_err("dns lookup failed");
-        free(ipstr);
-        return NULL;
-    }
-
-    struct addrinfo *first = responses;
-    struct in_addr *addr = &(((struct sockaddr_in *) responses->ai_addr)->sin_addr);
-    
-    inet_ntop(first->ai_family, addr, ipstr, sizeof(char) * INET_ADDRSTRLEN);
-
-    freeaddrinfo(responses);
-
-    return ipstr;
-}
-
 int main(int ac, char **av)
 {
     (void) ac;
@@ -204,7 +56,7 @@ int main(int ac, char **av)
         return 1;
     }
 
-    char *packet = create_packet(payload_size);
+    char *packet = packet_create(payload_size);
     if (packet == NULL)
     {
         close(sockfd);
@@ -248,14 +100,19 @@ int main(int ac, char **av)
             }
             gettimeofday(&stop, NULL);
         }
-        while (len == packet_size && packet_check(buffer, packet_size) == 0 && pktcmp(packet, buffer, packet_size) == 0);
+        while (len == packet_size && packet_check(buffer, packet_size) == 0 && packet_compare(packet, buffer, packet_size) == 0);
 
         double time_interval = ((stop.tv_sec - start.tv_sec) * 1000 + (stop.tv_usec - start.tv_usec)) / 1000;
         printf("icmp reply received %fms\n", time_interval);
         
         sleep(1);
 
-        update_packet(packet, payload_size);
+        if (packet_update(packet, payload_size))
+        {
+            close(sockfd);
+            free(buffer);
+            free(packet);
+        }
     }
     free(packet);
     free(buffer);

src/packet.c

@@ -0,0 +1,120 @@
+#include "print.h"
+#include <fcntl.h>
+#include <netinet/ip_icmp.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static int fill_with_random(char *str, size_t nb)
+{
+    int fd;
+    
+    fd = open("/dev/random", O_RDONLY);
+    if (fd < 0)
+    {
+        print_err("error: open /dev/random failed.");
+        return 1;
+    }
+    if (read(fd, str, nb) != (ssize_t) nb)
+    {
+        close(fd);
+        print_err("error: read /dev/random failed.");
+        return 2;
+    }
+    close(fd);
+    return 0;
+}
+
+static unsigned short checksum(void *b, int len) {
+    unsigned short *buf = b;
+    unsigned int sum = 0;
+    unsigned short result;
+
+    for (sum = 0; len > 1; len -= 2)
+        sum += *buf++;
+    if (len == 1)
+        sum += *(unsigned char *)buf;
+    sum = (sum >> 16) + (sum & 0xFFFF);
+    sum += (sum >> 16);
+    result = ~sum;
+    return result;
+}
+
+int packet_compare(const char *sent, const char *received, size_t packet_size)
+{
+    const struct icmphdr *sent_hdr = (const struct icmphdr*) sent;
+    const struct icmphdr *received_hdr = (const struct icmphdr*) received;
+    
+    if (received_hdr->type != 0 || received_hdr->code != 8)
+        return 1;
+
+    if (received_hdr->un.echo.sequence == sent_hdr->un.echo.sequence)
+        return 2;
+
+    const char *sent_payload = sent + sizeof(struct icmphdr);
+    const char *received_payload = received + sizeof(struct icmphdr);
+
+    return memcmp(sent_payload, received_payload, packet_size - sizeof(struct icmphdr));
+}
+
+int packet_check(char *packet, size_t packet_size)
+{
+    struct icmphdr *hdr = (struct icmphdr *) packet;
+    
+    const uint16_t checksum_bak = hdr->checksum;
+    hdr->checksum = 0;
+    int tmp = checksum(packet, packet_size);
+    hdr->checksum = checksum_bak;
+
+    return tmp - checksum_bak;
+}
+
+
+int packet_update(char *packet, size_t payload_size)
+{
+    static size_t sequence = 1;
+    size_t hdr_size = sizeof(struct icmphdr);
+    size_t packet_size = hdr_size + payload_size;
+
+    struct icmphdr *hdr = (void*)packet;
+
+    hdr->un.echo.sequence = htons(sequence++);
+    hdr->checksum = 0;
+
+    if (fill_with_random(packet + hdr_size, payload_size))
+        return 1;
+
+    hdr->checksum = checksum(packet, packet_size);
+
+    return 0;
+}
+
+void *packet_create(size_t payload_size)
+{
+    size_t hdr_size = sizeof(struct icmphdr);
+    size_t packet_size = hdr_size + payload_size;
+
+    char *packet;
+
+    packet = malloc(packet_size);
+    if (packet == NULL)
+    {
+        print_err("allocation failed.");
+        return NULL;
+    }
+
+    struct icmphdr *hdr = (struct icmphdr *)packet;
+
+    hdr->type = ICMP_ECHO;
+    hdr->code = 0;
+    hdr->un.echo.id = htons(getpid() & 0xFFFF);
+
+    if (packet_update(packet, payload_size))
+    {
+        free(packet);
+        return NULL;
+    }
+
+    return packet;
+}

src/packet.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <stddef.h>
+
+int packet_compare(const char *sent, const char *received, size_t packet_size);
+int packet_check(char *packet, size_t packet_size);
+int packet_update(char *packet, size_t payload_size);
+void *packet_create(size_t payload_size);

src/print.c

@@ -0,0 +1,15 @@
+
+
+#include <stdarg.h>
+#include <stdio.h>
+
+void print_err(const char *format, ...)
+{
+    va_list args;
+
+    puts("ft_ping: ");
+    va_start(args, format);
+    vprintf(format, args);
+    va_end(args);
+    putchar('\n');
+}

src/print.h

@@ -0,0 +1,3 @@
+#pragma once
+
+void print_err(const char *format, ...);