add: parsing

src/main.c

@@ -1,7 +1,9 @@
 #include "dns.h"
 #include "host.h"
 #include "packet.h"
+#include "parsing.h"
 #include "print.h"
+#include "setting.h"
 #include <netinet/ip.h>
 #include <signal.h>
 #include <stddef.h>
@@ -32,30 +34,81 @@ void signal_handler(int code)
     loop = false;
 }
 
+static int parsing_number(const char *str, size_t min, size_t max, size_t *out)
+{
+    size_t number = 0;
+    const char *start = str;
+
+    while (*start != '\0')
+    {
+        size_t tmp = number * 10 + *start - '0';
+        if (tmp < number)
+            goto value_error;
+        number = tmp;
+        start++;
+    }
+
+    if (min > number || number > max)
+        goto value_error;
+
+    *out = number;
+
+    return 0;
+
+value_error:
+    print_err("invalid argument: '%s': out of range: %zu <= value <= %zu", str, min, max);
+    return 1;
+}
+
+static int get_setting(char * const *av, struct setting *setting)
+{
+    struct param parameters[] = {
+        {NULL, "?", OPTION, false},
+        {NULL, "v", OPTION, false},
+        {NULL, "f", OPTION, false},
+        {NULL, "n", OPTION, false},
+        {NULL, "W",ARGUMENT, "0"},
+        {"ttl", NULL, ARGUMENT, "116"},
+        {NULL, NULL, 0, NULL},
+    };
+    char *hostname = parsing(av, parameters);
+    if (hostname == NULL)
+        return 1;
+    setting->dest.hostname = hostname;
+
+    setting->help = parameters[0].value;
+    setting->verbose = parameters[1].value;
+    setting->flood = parameters[2].value;
+    setting->numeric_only = parameters[3].value;
+    if (parsing_number(parameters[4].value, 0, 2147483647, &setting->timeout))
+        return 1;
+    if (parsing_number(parameters[5].value, 0, 255, &setting->ttl))
+        return 1;
+    return  0;
+}
+
 int main(int ac, char **av)
 {
     (void) ac;
-    (void) av;
+    struct setting settings;
 
-    struct host host;
-
-    host.hostname = "localhost";
+    get_setting(av + 1, &settings);
 
     size_t payload_size = 20;
     size_t packet_size = sizeof(struct icmphdr) + payload_size;
 
     signal(SIGINT, signal_handler);
 
-    if (dns_lookup(host.hostname, host.ip))
+    if (dns_lookup(&settings.dest))
         return 5;
 
-    host.reverse_dns = dns_reverse_lookup(host.ip);
+    
+    settings.dest.ip.sin_family = AF_INET;
+    settings.dest.ip.sin_port = htons(0);       
+    inet_pton(AF_INET, settings.dest.ipstr, &settings.dest.ip.sin_addr);
 
-    struct sockaddr_in dest;
 
-    dest.sin_family = AF_INET;
-    dest.sin_port = htons(0);       
-    inet_pton(AF_INET, host.ip, &dest.sin_addr);
+    dns_reverse_lookup(&settings.dest);
 
     int sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
 
@@ -89,7 +142,7 @@ int main(int ac, char **av)
         struct timeval stop, start;
 
         gettimeofday(&start, NULL);
-        if (sendto(sockfd, packet, packet_size, 0,  (struct sockaddr *) &dest, sizeof(dest)) == -1)
+        if (sendto(sockfd, packet, packet_size, 0,  (struct sockaddr *) &settings.dest.ip, sizeof(settings.dest.ip)) == -1)
         {
             print_err("error: send packet failed.");
             free(packet);
@@ -113,7 +166,7 @@ int main(int ac, char **av)
 
         double time_interval = ((stop.tv_sec - start.tv_sec) * 1000 + ((double)stop.tv_usec - (double) start.tv_usec)  / 1000);
         struct icmphdr *hdr = (struct icmphdr *) packet;
-        printf("%zu bytes from %s (%s): icmp_seq=%d, ttl=%u, time=%fms\n", payload_size + sizeof(struct icmphdr) + sizeof(struct iphdr) + sizeof(struct ether_header), host.reverse_dns, host.ip, htons(hdr->un.echo.sequence), 116, time_interval);
+        printf("%zu bytes from %s (%s): icmp_seq=%d, ttl=%u, time=%fms\n", payload_size + sizeof(struct icmphdr) + sizeof(struct iphdr) + sizeof(struct ether_header), settings.dest.reverse_dns, settings.dest.ipstr, htons(hdr->un.echo.sequence), 116, time_interval);
         
         sleep(1);