From 4e2f824d997bae569e5418af3ee7d192ac6384ee Mon Sep 17 00:00:00 2001
From: ston1th <ston1th@giftfish.de>
Date: Sat, 20 May 2017 11:31:51 +0200
Subject: [PATCH] some improvements

---
 ddns.c | 109 +++++++++++++++++++++------------------------------------
 1 file changed, 40 insertions(+), 69 deletions(-)

diff --git a/ddns.c b/ddns.c
index c6107cc..705e7f4 100644
--- a/ddns.c
+++ b/ddns.c
@@ -6,45 +6,30 @@
 #include <sys/file.h>
 #include <err.h>
 
-#define SEP '='
 #define MAX_QUERY_LEN 255
-#define MAX_QUERY_ARGS 2
 #define IP_LEN 16
 #define IP_FILE "ip.txt"
 #define TOKEN "<empty>"
 
-void free_arr(void *arr) {
-        uintptr_t *a = arr;
-        while(*a) {
-                free((void*)*a++);
-        }
-        free(arr);
-}
-
-char **parse(const char *str) {
-        const char *s = str;
-        char *qs, *token;
-        char **arr = NULL;
-        int c = 1, argc = 0;
-        qs = strdup(s);
-        while((token = strsep(&qs, "&")) != NULL) {
-                if(++argc > MAX_QUERY_ARGS)
+char *form_value(const char *args, const char *field) {
+        char *s;
+        char *token;
+        char *value;
+        char *ret = NULL;
+        size_t len;
+        len = strlen(field);
+        s = strdup(args);
+        while((token = strsep(&s, "&")) != NULL) {
+                if(strlen(token) < len)
+                        continue;
+                if(strncmp(field, token, len) == 0) {
+                        value = strchr(token, '=');
+                        ret = strdup(value);
                         break;
-                c++;
-                if(arr == NULL) {
-                        arr = malloc(c*sizeof(char *));
-                        if(arr == NULL)
-                                break;
-                } else {
-                        arr = realloc(arr, c*sizeof(char *));
-                        if(arr == NULL)
-                                break;
                 }
-                arr[c-1] = NULL;
-                arr[c-2] = strdup(token);
         }
-        free(qs);
-        return(arr);
+        free(s);
+        return(ret);
 }
 
 void header() {
@@ -73,46 +58,32 @@ int ctc(const char *a, const char *b) {
         return(ctb(v, 0));
 }
 
-int set_ip(char *env, int fd) {
-        char *ip = NULL, *token = NULL, *tmp = NULL;
-        int ret = -1, len = 0;
-        char **arg = parse(env);
-        char **arr = arg;
-        if(arg == NULL)
-                return(0);
-        for(; *arr; arr++) {
-                if(strncmp(*arr, "ip", 2) == 0) {
-                        tmp = strchr(*arr, SEP);
-                        if(++tmp == NULL)  
-                                continue;
-                        ip = strdup(tmp);
-                } else if(strncmp(*arr, "token", 5) == 0) {
-                        tmp = strchr(*arr, SEP);
-                        if(++tmp == NULL)  
-                                continue;
-                        token = strdup(tmp);
-                }
-        }
-        tmp = NULL;
-        free_arr(arg);
-        if(ctc(token, TOKEN) == 1) {
-                if(ip) {
-                        len = strlen(ip);
-                        if(len >= IP_LEN-1)
-                                len = IP_LEN-1;
-                        write(fd, ip, len);
-                }
-                close(fd);
-        } else
-                ret = 1;
-        if(ip)
+int set_ip(char *env, int wfd) {
+        char *ip = NULL, *token = NULL;
+        int ret = 1;
+        size_t len;
+        ip = form_value(env, "ip");
+        if(!ip)
+                return(ret);
+        token = form_value(env, "token");
+        if(!token)
                 free(ip);
-        if(token)
-                free(token);
+                return(ret);
+        if(ctc(token, TOKEN) == 1) {
+                len = strlen(ip);
+                if(len >= IP_LEN-1)
+                        len = IP_LEN-1;
+                write(wfd, ip, len);
+                close(wfd);
+                ret = 0;
+        } else
+                ret = 2;
+        free(ip);
+        free(token);
         return(ret);
 }
 
-char *err_msg[2] = {"wrong input", "wrong token"};
+char *err_msg[2] = {"invalid arguments", "wrong token"};
 
 int main(void) {
         char *env = NULL;
@@ -136,8 +107,8 @@ int main(void) {
                         puts("query longer than 255 bytes");
                         return(EXIT_SUCCESS);
                 }
-                if((errn = set_ip(env, wfd)) >= 0)
-                        puts(err_msg[errn]);
+                if((errn = set_ip(env, wfd)) > 0)
+                        puts(err_msg[errn-1]);
                 else
                         puts("ok");
         } else {