add: parsing

src/dns.c

@@ -1,5 +1,6 @@
 
 
+#include "host.h"
 #include "print.h"
 #include <arpa/inet.h>
 #include <stddef.h>
@@ -8,7 +9,7 @@
 #include <string.h>
 #include <strings.h>
 
-int dns_lookup(const char *hostname, char *ipstr)
+int dns_lookup(struct hostenv *host)
 {
     struct addrinfo filter;
 
@@ -16,48 +17,34 @@ int dns_lookup(const char *hostname, char *ipstr)
     filter.ai_family = AF_INET; 
 
     struct addrinfo *responses;
-    if (getaddrinfo(hostname, NULL, &filter, &responses) != 0)
+    if (getaddrinfo(host->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);
+    struct in_addr *addr = &(((struct sockaddr_in *) first->ai_addr)->sin_addr);
     
-    inet_ntop(first->ai_family, addr, ipstr, sizeof(char) * INET_ADDRSTRLEN);
+    inet_ntop(first->ai_family, addr, host->ipstr, sizeof(char) * INET_ADDRSTRLEN);
 
     freeaddrinfo(responses);
 
     return 0;
 }
 
-char *dns_reverse_lookup(const char *ipstr)
+int dns_reverse_lookup(struct hostenv *host)
 {
-    struct sockaddr_in sa;
-    char host[NI_MAXHOST];
-
-    bzero(&sa, sizeof(sa));
-    sa.sin_family = AF_INET;
-
-    printf("%s\n", ipstr);
-
-    if (inet_pton(AF_INET, ipstr, &sa.sin_addr) <= 0)
-    {
-        print_err("inet_pton failed");
-        return NULL;
-    }
-
     int ret = getnameinfo(
-        (struct sockaddr *)&sa, sizeof(sa),
+        (struct sockaddr *)&host->ip, sizeof(host->ip),
-        host, sizeof(host),
+        host->reverse_dns, sizeof(host->reverse_dns),
         NULL, 0, NI_NAMEREQD);
 
     if (ret != 0) 
     {
         print_err("reverse dns failed.");
-        return NULL;
+        return 1;
     }
 
-    return strdup(host);
+    return 0;
 }

src/dns.h

@@ -1,4 +1,6 @@
 #pragma once
 
-int dns_lookup(const char *hostname, char *ipstr);
+#include "host.h"
-char *dns_reverse_lookup(const char *ipstr);
+
+int dns_lookup(struct hostenv *host);
+int dns_reverse_lookup(struct hostenv *host);

src/host.h

@@ -1,9 +1,11 @@
 #pragma once
 
+#include <netdb.h>
 #include <netinet/in.h>
 
-struct host {
+struct hostenv {
-    char ip[INET_ADDRSTRLEN];
+    char ipstr[INET_ADDRSTRLEN];
+    struct sockaddr_in ip;
     char *hostname;
-    char *reverse_dns;
+    char reverse_dns[NI_MAXHOST];
 };

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;
+    get_setting(av + 1, &settings);
-
-    host.hostname = "localhost";
 
     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;
+    dns_reverse_lookup(&settings.dest);
-    dest.sin_port = htons(0);       
-    inet_pton(AF_INET, host.ip, &dest.sin_addr);
 
     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);
 

src/parsing.c

@@ -6,31 +6,22 @@
 #include <stdbool.h>
 #include <string.h>
 
-static struct param parameters[] = {
+
-    {NULL, "?", OPTION, false},
-    {NULL, "v", OPTION, false},
-    {NULL, "f", OPTION, false},
-    {NULL, "n", OPTION, false},
-    {NULL, "w", ARGUMENT, NULL},
-    {NULL, "W",ARGUMENT, NULL},
-    {"ttl", NULL, ARGUMENT, "116"},
-    {NULL, NULL, NULL, NULL},
-};
 
 static struct param *get_parameter(struct param parameters[], const char *str)
 {
-    size_t count = str[0] == '-' + str[1] == '-';
+    size_t count = (str[0] == '-') + (str[1] == '-');
     for (size_t i = 0; parameters[i].name || parameters[i].alias; i++)
     {
-        if (count == 2 && !strcmp(parameters[i].name, str + count))
+        if (count == 2 && parameters[i].name != NULL && !strcmp(parameters[i].name, str + count))
             return parameters + i;
-        else if (count == 1 && !strcmp(parameters[i].alias, str + count))
+        else if (count == 1 && parameters[i].alias != NULL && !strcmp(parameters[i].alias, str + count))
             return parameters + i;
     }
     return NULL;
 }
 
-int parsing(const char * const *av)
+char *parsing(char * const *av, struct param parameters[])
 {
     char *host;
     for (size_t i = 0; av[i]; i++)
@@ -55,5 +46,5 @@ int parsing(const char * const *av)
             host = (char*) av[i];
         }
     }
-    return 0;
+    return host;
 }

src/parsing.h

@@ -11,3 +11,5 @@ struct param  {
     e_type type;
     void *value;
 };
+
+char *parsing(char * const *av, struct param parameters[]);

src/setting.h

@@ -0,0 +1,17 @@
+#pragma once
+
+#include "host.h"
+
+#include <stddef.h>
+#include <stdbool.h>
+
+struct setting
+{
+    bool help;
+    bool verbose;
+    bool flood;
+    bool numeric_only;
+    size_t timeout;
+    size_t ttl;
+    struct hostenv dest;
+};