fix: remove cluttered state machine code

Makefile

@@ -1,6 +1,6 @@
 CC=gcc
 CFLAGS=-g3
-CFILES=tinyparser.c headers.c
+CFILES=tinyparser.c strings.c
 CFILES_STREECMP=streecmp/streecmp.c
 OUTPUT=tinyparser
 

README

@@ -20,7 +20,6 @@ TODO
     
     * headers table needs length fields 
     * refactor header parsing 
-    * refactor state machine 
     * implement tests 
     * integrations with tinyproxy..?
 

streecmp

@@ -1 +1 @@
-Subproject commit 42ed96353d186078e34e4c541e7c92d433cda138
+Subproject commit ca1293aa8f123adb91d80f687933ea5c596c114a

strings.c

@@ -1,3 +1,13 @@
+char *methods = "GET\n"
+                "HEAD\n"
+                "POST\n"
+                "PUT\n"
+                "DELETE\n"
+                "CONNECT\n"
+                "OPTIONS\n"
+                "TRACE\n"
+                "PATCH\n";
+
 char *headers = "A-IM\n"
                 "Accept\n"
                 "Accept-Charset\n"

tinyparser.c

@@ -5,16 +5,16 @@
 #include "streecmp/streecmp.h"
 
 extern char *headers;
+extern char *methods;
 
-enum errs err = err_init;
+int method = 0;
-enum states state = state_init;
-enum methods method = method_init;
 char *uri = NULL; 
 char *ver = NULL;
 int uri_len = 0;
 int ver_len = 0;
 
-struct nod *header_tree = NULL;
+struct nod *header_tree = NULL; 
+struct nod *method_tree = NULL;
 char **header_table = NULL; 
 
 int read_line(char **buffer, char **buffer_limit) {
@@ -35,39 +35,6 @@ int read_line(char **buffer, char **buffer_limit) {
     return ret;
 }
 
-int cmp_orig(char *ch, char *orig, char *limit) {
-    int diff = 0;
-    for (; *orig != '\0' && *ch != '\0' && ch < limit; orig++, ch++, diff++) 
-        if (*orig != *ch)
-            return -1;
-
-    return diff;
-}
-
-int cmp_ascii(char *ch, char *limit) {
-    int diff = 0; 
-    for (; *ch != '\0' && *ch != ' ' && ch < limit; ch++, diff++) {
-        if (*ch >= '0' && *ch <= '9')   continue;
-        if (*ch >= 'A' && *ch <= 'Z')   continue;
-        if (*ch >= 'a' && *ch <= 'z')   continue;
-        if (*ch >= '#' && *ch <= '/')   continue;
-        if (*ch == '!')                 continue;
-        if (*ch == ':')                 continue;
-        if (*ch == ';')                 continue;
-        if (*ch == '=')                 continue;
-        if (*ch == '?')                 continue;
-        if (*ch == '@')                 continue;
-        if (*ch == '[')                 continue;
-        if (*ch == ']')                 continue;
-        if (*ch == '_')                 continue;
-        if (*ch == '~')                 continue;
-
-        return -1;
-    }
-
-    return diff;
-}
-
 int parse_header(char *offset, int len) {
     int cursor = 0;
     int ret = 0; 
@@ -94,108 +61,55 @@ int parse_header(char *offset, int len) {
 }
 
 int parse_title(char *offset, int len) {
-    int cursor = 0;
+    int ret = 0; 
+    int diff = 0; 
+    char *cursor = offset;
+    char *cursor_lim = cursor+len;
 
-    while (state != state_title_ok && state != state_title_err) {
+    // method
-        if (cursor >= len) {
+    char *method_lim = strchr(offset, ' ');
-            state = state_title_err;
+    if (!method_lim) {
-            err = err_parse_title;
+        return -1;
-        }
-
-        int ret = 0; 
-        char *ch = offset+cursor;
-        char *lim = offset+len-1;
-
-        switch (state) {
-        case state_init: 
-            state = state_title_method;
-            break;
-        case state_title_method: 
-            if ((ret = cmp_orig(ch, "GET", lim))) {
-                cursor += ret;
-                state = state_title_after_method;
-                method = method_get;
-                break;
-            }
-            if ((ret = cmp_orig(ch, "POST", lim))) {
-                cursor += ret;
-                state = state_title_after_method;
-                method = method_post;
-                break;
-            }
-            if ((ret = cmp_orig(ch, "HEAD", lim))) {
-                cursor += ret;
-                state = state_title_after_method;
-                method = method_head;
-                break;
-            }
-
-            state = state_title_err;
-            err = err_parse_title_method;
-            break;
-        case state_title_after_method: 
-            cursor++;
-            state = state_title_uri;
-            break;
-        case state_title_uri: 
-            if ((ret = cmp_ascii(ch, lim)) <= 0) {
-                state = state_title_err;
-                err = err_parse_title_uri;
-                break;
-            }
-
-            if (!(uri = strndup(ch, ret))) {
-                state = state_title_err;
-                err = err_memory;
-                break;
-            }
-
-            uri_len = ret;
-            cursor += ret;
-            state = state_title_after_uri;
-            break;
-        case state_title_after_uri: 
-            cursor++; 
-            state = state_title_version;
-            break;
-        case state_title_version: 
-            if ((ret = cmp_ascii(ch, lim)) <= 0) {
-                state = state_title_err;
-                err = err_parse_title_version;
-                break;
-            }
-
-            if (!(ver = strndup(ch, ret))) {
-                state = state_title_err;
-                err = err_memory;
-                break;
-            }
-
-            ver_len = ret;
-            cursor += ret;
-            state = state_title_ok;
-            break;
-        case state_title_ok: 
-            for (;ch < lim;ch++) {
-                if (*ch == ' ') continue;
-                if (*ch == '\t') continue;
-                if (*ch == '\0') continue;
-                if (*ch == '\r') continue;
-
-                state = state_title_err;
-                err = err_parse_title;
-                break;
-            }
-            break;
-        case state_title_err:
-            fprintf(stderr, "failed\n");
-            return -1;
-            break;
-        default: 
-            break;
-        }
     }
 
+    diff = method_lim-cursor;
+    ret = streencmp(method_tree, cursor, diff);
+    if (ret == 0) {
+        return -1;
+    }
+
+    method = ret;
+    cursor += diff;
+
+    // white space 
+    while (*cursor == ' ') {
+        cursor++;
+    }
+
+    // uri 
+    char *uri_lim = strchr(cursor, ' ');
+    if (!uri_lim) {
+        return -1;
+    }
+
+    diff = uri_lim-cursor;
+    uri = cursor;
+    uri_len = diff;
+
+    cursor += diff;
+    
+    // white space 
+    while (*cursor == ' ') {
+        cursor++;
+    }
+
+    // ver
+    diff = cursor_lim-cursor;
+    ver = cursor;
+    ver_len = diff;
+
+    cursor += diff;
+
     return 0;
 }
 
@@ -217,7 +131,6 @@ int parse_request(char *buffer) {
         
         // IF END OF MESSAGE
         if (!header_len) {
-            state = state_fin;
             break;
         }
 
@@ -227,9 +140,6 @@ int parse_request(char *buffer) {
         }
     }
 
-    free(uri);
-    free(ver);
-
     return 0;
 }
 
@@ -249,8 +159,20 @@ int main(void) {
         return -1;
     }
 
+    method_tree = allocnod();
+    if (!method_tree) {
+        fprintf(stderr, "Not enough dynamic memory\n");
+        return -1;
+    }
+
     ret = gentree(header_tree, headers, NULL);
-    if (gentree < 0) {
+    if (ret < 0) {
+        fprintf(stderr, "Failed generating the header comparison tree\n");
+        return -1;
+    }
+
+    ret = gentree(method_tree, methods, NULL);
+    if (ret < 0) {
         fprintf(stderr, "Failed generating the header comparison tree\n");
         return -1;
     }
@@ -261,8 +183,14 @@ int main(void) {
         return -1;
     }
 
-    fprintf(stderr, "Finished parsing request\n");
+    fprintf(stderr, "[+] Finished parsing request\n"
+                    "       method: %d\n"
+                    "       uri   : %.*s\n"
+                    "       ver   : %.*s\n",
+                    method, uri_len, uri, ver_len, ver
+            );
 
+    frenod(method_tree);
     frenod(header_tree);
     free(header_table);
     free(str);

tinyparser.h

@@ -13,49 +13,17 @@
 
 // ENUMS
 
-// SRC:https://datatracker.ietf.org/doc/html/rfc2616
-enum errs {
-    err_init = 0,
-    err_generic,
-    err_memory,
-    err_parse_title,
-    err_parse_title_method,
-    err_parse_title_uri,
-    err_parse_title_version,
-    err_parse_header_not_found
-};
-
-// SRC:https://datatracker.ietf.org/doc/html/rfc2616
-enum states {
-    state_init = 0,
-    state_title_method,
-    state_title_after_method,
-    state_title_uri,
-    state_title_after_uri,
-    state_title_version,
-    state_title_ok,
-    state_title_err,
-    
-    state_header_init, 
-    state_header_alloc,
-    state_header_parse,
-    state_header_not_found,
-    state_header_ok,
-    state_header_err,
-
-    state_body_init,
-    state_body_ok,
-    state_body_err,
-
-    state_fin,
-};
-
 // SRC:https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods
 enum methods {
-    method_init = 0,
+    method_get = 1,
-    method_get,
+    method_head,
     method_post,
-    method_head
+    method_put,
+    method_delete,
+    method_connect,
+    method_options,
+    method_trace,
+    method_patch
 };
 
 // SRC:https://en.wikipedia.org/wiki/List_of_HTTP_header_fields