Merge pull request #1 from RemcodM/master

Fixing security bugs and memory leaks.

arg_parse.c

@@ -13,7 +13,7 @@ int get_argc(char *s)
             sp++;
         if (*sp == '\0')
             return count;
-        else 
+        else
             count++;
         while (!isspace(*sp) && *sp != '\0') 
             sp++;
@@ -33,7 +33,7 @@ char **get_args(char *s, int index)
 {
     char **args, arg[BUFSIZE], *argp;
     int i;
-    args = (char **) malloc (BUFSIZ);    
+    args = (char **) malloc (BUFSIZE);
 
     s += index;
     _argc = get_argc(s);
@@ -48,7 +48,7 @@ char **get_args(char *s, int index)
             _argc--;
             goto top;
         }
-        while (!isspace(*s) || *s == '\0') 
+        while (!isspace(*s) && *s != '\0')
             *argp++ = *s++;
 
         *argp = '\0';
@@ -58,8 +58,9 @@ char **get_args(char *s, int index)
     return args;
 }
 
-char *get_flags(char *buf, char *flags)
+char *get_flags(char *buf)
 {
+    char* flags = (char *) malloc(BUFSIZE);
     while (*buf != '\0') {
         if (*buf == '-') {
             buf++;
@@ -71,3 +72,14 @@ char *get_flags(char *buf, char *flags)
     *flags = '\0';
     return flags;
 }
+
+void free_args(char **args) {
+    for (int i = 0; i < _argc; i++) {
+        free(args[i]);
+    }
+    free(args);
+}
+
+void free_flags(char *flags) {
+    free(flags);
+}

arg_parse.h

@@ -6,6 +6,7 @@
 int get_argc(char *s);
 char *skip_flag(char *s);
 char **get_args(char *s, int index);
-char *get_flags(char *buf, char *flags);
-
+char *get_flags(char *buf);
+void free_args(char **args);
+void free_flags(char *flags);
 #endif

cli.c

@@ -101,6 +101,8 @@ int cat(const char *name, int nflag)
     if (c != '\n')
         putchar('\n');
 
+    fclose(fp);
+
     return 0;
 }
 
@@ -172,7 +174,8 @@ int main(void)
         getcwd(cwd, BUFSIZE);
         printf("cli:%s%% ", (cwd == NULL) ? "" : cwd);
 
-        gets(buf);
+        fgets(buf, BUFSIZE, stdin);
+
         if (strlen(buf) == 0)   
             continue;
         if (strncmp(buf, "rm", 2) == 0 && !isalnum(buf[2]))
@@ -194,7 +197,7 @@ int main(void)
         else
             printf("cli: not a valid command.\n"
                    "type 'help' for a list of options\n\n");
-    } while (strcmp(buf, "exit") != 0);
+    } while (strcmp(buf, "exit\n") != 0);
 
     return 0;
 } 

cmd_mains.c

@@ -1,14 +1,15 @@
 #include "misc.h"
 #include "cmd_mains.h"
+#include "arg_parse.h"
 
 int rm_main(char *buf)
 {
-    char **args, flags[5];
+    char **args;
     int pflag = 0, vflag = 0, rflag = 0, hflag = 0, i = 0;
-        
+
     args = get_args(buf, 2);
-    get_flags(buf, flags);
-    
+    char* flags = get_flags(buf);
+
     if (flags[0] != '\0') {
         do {
             switch (flags[i])
@@ -45,16 +46,19 @@ int rm_main(char *buf)
     for (i = 0; i < _argc; ++i) {
         rm(args[i], vflag, pflag, rflag);
     }
+
+    free_args(args);
+    free_flags(flags);
     return 0;
 }
 
 int ls_main(char *buf)
 {
-    char **args, flags[4];
+    char **args;
     int aflag = 0, iflag = 0, rflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 2);
-    get_flags(buf, flags);
+    char* flags = get_flags(buf);
 
     if (flags[0] != '\0') {
         do {
@@ -94,16 +98,18 @@ int ls_main(char *buf)
     } else
         ls(args[0], aflag, iflag, rflag);
 
+    free_args(args);
+    free_flags(flags);
     return 0;
 }
 
 int mkdir_main(char *buf)
 {
-    char **args, flags[5];
+    char **args;
     int vflag = 0, hflag = 0, i = 0;
-    
+
     args = get_args(buf, 5);
-    get_flags(buf, flags);
+    char* flags = get_flags(buf);
 
    if (flags[0] != '\0') {
        do {
@@ -130,22 +136,23 @@ int mkdir_main(char *buf)
    if (_argc == 0) {
        printf("mkdir: no arguments given\n\n");
        goto mkdir_usage;
-       return 1;
    } else {
-       for (i = 0; i < _argc; ++i) 
+       for (i = 0; i < _argc; ++i)
            makedir(args[i], vflag);
    }
 
+   free_args(args);
+   free_flags(flags);
    return 0;
 }
 
 int cat_main(char *buf)
 {
-    char **args, flags[5];
+    char **args;
     int nflag = 0, hflag = 0, i = 0;
 
     args = get_args(buf, 3);
-    get_flags(buf, flags);
+    char* flags = get_flags(buf);
 
     if (flags[0] != '\0') {
         do {
@@ -178,6 +185,8 @@ int cat_main(char *buf)
     } else
         cat(args[0], nflag);
 
+    free_args(args);
+    free_flags(flags);
     return 0;
 }
 
@@ -199,6 +208,6 @@ int cd_main(char *buf)
     else
         cd(args[0]);
 
+    free_args(args);
     return 0;
-}
-
+}

cmd_mains.h

@@ -11,5 +11,4 @@ int cat(const char *name, int nflag);
 int cat_main(char *buf);
 int cd(const char *name);
 int cd_main(char *buf);
-
 #endif

misc.c

@@ -39,7 +39,6 @@ void usage(void)
            "cd\tchange working directory.\n\n"
            "appending \" -h\" to most commands will give\n"
            "additional info regarding that command\n\n");
-    exit(0);
 }
 
 char *strdup(const char *s)

misc.h

@@ -29,7 +29,7 @@ void usage(void);
 int get_argc(char *s);
 char **get_args(char *s, int index);
 char *skip_flags(char *s);
-char *get_flags(char *buf, char *flags);
+char *get_flags(char *buf);
 bool prompt(char *fmt, ...);
 
 #endif