Parsing of simple requests. HashMap.

CMakeLists.txt

@@ -9,6 +9,8 @@ add_library(
     STATIC
     src/httpserver.h
     src/httpserver.c
+        src/utils/hashmap.c
+        src/utils/hashmap.h
 )
 
 add_executable(

app/main.c

@@ -5,14 +5,15 @@
 #include "main.h"
 #include <stdio.h>
 
-struct HttpResponse* handleRequest(struct HttpRequest* request)
+http_response_t* handle_request(http_request_t* request)
 {
-    struct HttpResponse* http_response = {};
+    http_response_t* http_response = {};
     return http_response;
 }
 
 int main() {
-    struct HttpServer http_server;
+    http_server_t http_server;
+    http_server.handle_request = &handle_request;
     printf("Starting the server...\n");
     start_http_server(&http_server, ADDRESS, PORT);
     printf("Bye!\n");

app/main.h

@@ -9,8 +9,7 @@
 #define ADDRESS "127.0.0.1"
 #define PORT 8080
 
-struct HttpResponse* handleRequest(struct HttpRequest* request);
-
+http_response_t* handle_request(http_request_t* request);
 int main();
 
 #endif //SIMPLEHTTPSERVER_MAIN_H

src/httpserver.c

@@ -3,17 +3,36 @@
 //
 
 #include "httpserver.h"
-#include <stdio.h>
 
-void start_http_server(struct HttpServer* http_server, const char *addr, const short port)
+struct {
+    const char* name;
+    enum http_method method;
+} method_map[] = {
+    { "GET", GET },
+    { "HEAD", HEAD },
+    { "POST", POST },
+    { "PUT", PUT },
+    { "DELETE", DELETE },
+    { "CONNECT", CONNECT },
+    { "OPTIONS", OPTIONS },
+    { "TRACE", TRACE },
+    { "PATCH", PATCH }
+};
+
+void start_http_server(http_server_t* http_server, const char *addr, const short port)
 {
     const int server_fd = socket(AF_INET, SOCK_STREAM, 0);
     if (server_fd == -1)
     {
-        printf("Failed to create new socket.\n");
+        perror("Failed to create new socket.\n");
         return;
     }
 
+    int opt = 1;
+    if (setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
+        perror("setsockopt(SO_REUSEADDR) failed");
+    }
+
     struct sockaddr_in address;
     address.sin_family = AF_INET;
     address.sin_addr.s_addr = inet_addr(addr);
@@ -22,14 +41,14 @@ void start_http_server(struct HttpServer* http_server, const char *addr, const s
     const int bind_c = bind(server_fd, (struct sockaddr*)&address, sizeof(address));
     if (bind_c == -1)
     {
-        printf("Failed to bind address.\n");
+        perror("Failed to bind address.\n");
         return;
     }
 
     const int listen_c = listen(server_fd, 3);
     if (listen_c == -1)
     {
-        printf("Failed to begin listening.\n");
+        perror("Failed to begin listening.\n");
         return;
     }
 
@@ -41,26 +60,194 @@ void start_http_server(struct HttpServer* http_server, const char *addr, const s
     close(server_fd);
 }
 
-void process_conn(struct HttpServer* http_server, const int server_fd, struct sockaddr* address, socklen_t* addr_len)
+void process_conn(http_server_t* http_server, const int server_fd, struct sockaddr* address, socklen_t* addr_len)
 {
     const int socket_d = accept(server_fd, address, addr_len);
     if (socket_d == -1)
     {
-        printf("Failed to accept connection.\n");
+        perror("Failed to accept connection.\n");
         return;
     }
 
     char buffer[1024] = {0};
+
     const ssize_t bytes_read = read(socket_d, buffer, 1024);
+    if (bytes_read == -1)
+    {
+        perror("Failed white reading socket.");
+        return;
+    }
+
+    // Debug output
     printf("Client message (%ld):\n", bytes_read);
     for (int i = 0; i < bytes_read; i++)
     {
-        if (buffer[i] == '\r')
-            continue;
-        putchar(buffer[i]);
+        if (buffer[i] != '\r')
+            putchar(buffer[i]);
     }
     putchar('\n');
     fflush(stdout);
 
+
+    enum http_request_parsing_stage request_parsing_stage = START_LINE_METHOD;
+    http_request_t http_request = {};
+
+    char method_str[8];
+    size_t method_str_len = 0;
+
+    char http_path[2048];
+    size_t http_path_len = 0;
+
+    char http_name[16];
+    size_t http_name_len = 0;
+
+    char header_key[256];
+    size_t header_key_length = 0;
+    char header_val[1024];
+    size_t header_val_length = 0;
+
+    http_request.http_content = nullptr;
+    http_request.http_content_len = 0;
+
+    for (int i = 0; i < bytes_read; i++)
+    {
+        bool drop = false;
+        switch (request_parsing_stage)
+        {
+        case START_LINE_METHOD:
+            if (buffer[i] == ' ')
+            {
+                method_str[method_str_len] = '\0';
+                http_request.http_method = parse_method_str(method_str, method_str_len);
+
+                if (http_request.http_method == UNKNOWN)
+                {
+                    perror("Unknown HTTP method!\n");
+                    drop = true;
+                    break;
+                }
+                request_parsing_stage = START_LINE_PATH;
+                break;
+            }
+
+            method_str[method_str_len++] = buffer[i];
+            break;
+        case START_LINE_PATH:
+            if (buffer[i] == ' ')
+            {
+                http_path[http_path_len] = '\0';
+                http_request.http_path = http_path;
+                http_request.http_path_len = http_path_len;
+                request_parsing_stage = START_LINE_HTTP_VERSION_NAME;
+                break;
+            }
+
+            http_path[http_path_len++] = buffer[i];
+            break;
+        case START_LINE_HTTP_VERSION_NAME:
+            if (buffer[i] == '/')
+            {
+                http_request.http_version.http_name = http_name;
+                http_request.http_version.http_name_len = http_name_len;
+
+                request_parsing_stage = START_LINE_HTTP_VERSION_MAJOR;
+                break;
+            }
+
+            http_name[http_name_len++] = buffer[i];
+            break;
+        case START_LINE_HTTP_VERSION_MAJOR:
+            if (buffer[i] == '.')
+            {
+                request_parsing_stage = START_LINE_HTTP_VERSION_MINOR;
+                break;
+            }
+
+            http_request.http_version.major = buffer[i] - '0';
+            break;
+        case START_LINE_HTTP_VERSION_MINOR:
+            if (i + 1 < bytes_read && buffer[i] == '\r' && buffer[i + 1] == '\n')
+            {
+                i++;
+                http_request.http_headers = new_hash_map();
+                request_parsing_stage = HEADERS_KEY;
+                break;
+            }
+
+            http_request.http_version.minor = buffer[i] - '0';
+            break;
+        case HEADERS_KEY:
+            if (i + 1 < bytes_read && buffer[i] == ':' && buffer[i + 1] == ' ')
+            {
+                i++;
+                header_key[header_key_length] = '\0';
+                request_parsing_stage = HEADERS_VALUE;
+                break;
+            }
+
+            if (i + 1 < bytes_read && buffer[i] == '\r' && buffer[i + 1] == '\n')
+            {
+                request_parsing_stage = CONTENT;
+                break;
+            }
+
+            header_key[header_key_length++] = buffer[i];
+            break;
+        case HEADERS_VALUE:
+            if (i + 1 < bytes_read && buffer[i] == '\r' && buffer[i + 1] == '\n')
+            {
+                i++;
+                header_val[header_val_length] = '\0';
+                char* key = calloc(header_key_length + 1, sizeof(char));
+                strncpy(key, header_key, header_key_length);
+                char* val = calloc(header_val_length + 1, sizeof(char));
+                strncpy(val, header_val, header_val_length);
+
+                printf(
+                    "Setting header '%s' (hash %d per cap %d): '%s'\n",
+                    key, hashcode(http_request.http_headers, key),
+                    http_request.http_headers->cap, val);
+
+                set(http_request.http_headers, key, val);
+                header_key[0] = '\0';
+                header_key_length = 0;
+                header_val[0] = '\0';
+                header_val_length = 0;
+                request_parsing_stage = HEADERS_KEY;
+                break;
+            }
+
+            header_val[header_val_length++] = buffer[i];
+            break;
+        case CONTENT:
+        default:
+            drop = true;
+            break;
+        }
+
+        if (drop)
+            break;
+    }
+
+    http_response_t* http_response = http_server->handle_request(&http_request);
+
+    // TODO: Send response
+
+    free_hash_map(http_request.http_headers);
+    free(http_response);
+
     close(socket_d);
 }
+
+enum http_method parse_method_str(const char* str, const size_t len)
+{
+    for (size_t i = 0; i < sizeof(method_map) / sizeof(method_map[0]); i++) {
+        if (strlen(method_map[i].name) == len &&
+            strncmp(str, method_map[i].name, len) == 0)
+        {
+            return method_map[i].method;
+        }
+    }
+
+    return UNKNOWN;
+}

src/httpserver.h

@@ -7,30 +7,79 @@
 #define SIMPLEHTTPSERVER_H
 
 #include <netdb.h>
-#include <netinet/in.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/socket.h>
-#include <sys/types.h>
 #include <unistd.h>
 #include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include "utils/hashmap.h"
 
-struct HttpRequest
+typedef struct http_version
 {
+    char* http_name; // has to end with "HTTP" btw
+    size_t http_name_len;
+    unsigned short major;
+    unsigned short minor;
+} http_version_t;
 
+enum http_method
+{
+    UNKNOWN,
+    GET,
+    HEAD,
+    POST,
+    PUT,
+    DELETE,
+    CONNECT,
+    OPTIONS,
+    TRACE,
+    PATCH
 };
 
-struct HttpResponse
+enum http_request_parsing_stage
 {
-
+    START_LINE_METHOD,
+    START_LINE_PATH,
+    START_LINE_HTTP_VERSION_NAME,
+    START_LINE_HTTP_VERSION_MAJOR,
+    START_LINE_HTTP_VERSION_MINOR,
+    HEADERS_KEY,
+    HEADERS_VALUE,
+    CONTENT
 };
 
-struct HttpServer
+typedef struct http_request
 {
-    struct HttpResponse* (*handleRequest)(struct HttpRequest* request);
-};
+    enum http_method http_method;
+    char* http_path;
+    size_t http_path_len;
+    http_version_t http_version;
+    hashmap_t* http_headers;
+    char* http_content;
+    size_t http_content_len;
+} http_request_t;
 
-void start_http_server(struct HttpServer* http_server, const char *addr, short port);
-void process_conn(struct HttpServer* http_server, int server_fd, struct sockaddr* address, socklen_t* addr_len);
+typedef struct http_response
+{
+    http_version_t http_version;
+    u_short http_status_code;
+    char* http_status_message;
+    size_t http_status_message_len;
+    hashmap_t* http_headers;
+    char* http_content;
+    size_t http_content_len;
+} http_response_t;
+
+typedef struct http_server
+{
+    http_response_t* (*handle_request)(http_request_t* request);
+} http_server_t;
+
+void start_http_server(http_server_t* http_server, const char *addr, short port);
+void process_conn(http_server_t* http_server, int server_fd, struct sockaddr* address, socklen_t* addr_len);
+enum http_method parse_method_str(const char* str, size_t len);
 
 #endif //SIMPLEHTTPSERVER_H

src/utils/hashmap.c

@@ -0,0 +1,125 @@
+//
+// Created by nazar on 13.09.2025.
+//
+
+#include "hashmap.h"
+
+#include <string.h>
+
+hashmap_t* new_hash_map() {
+    hashmap_t* this = malloc(sizeof *this);
+    this->cap = DEFAULT_CAPACITY;
+    this->len = 0;
+    this->list = calloc(this->cap, sizeof(pair_t*));
+    return this;
+}
+
+unsigned int hashcode(const hashmap_t* this, const char* key)
+{
+    unsigned int code;
+    for (code = 0; *key != '\0'; key++) {
+        code = *key + 31 * code;
+    }
+    return code % this->cap;
+}
+
+char* get(const hashmap_t* this, const char* key)
+{
+    const unsigned hash = hashcode(this, key);
+
+    const pair_t* existing_pair = this->list[hash];
+    if (existing_pair == nullptr)
+        return nullptr;
+
+    while (strcmp(existing_pair->key, key) != 0)
+    {
+        if (existing_pair->next == nullptr)
+            return nullptr;
+        existing_pair = existing_pair->next;
+    }
+
+    return existing_pair->val;
+}
+
+void set(hashmap_t* this, char* key, char* val)
+{
+    const unsigned hash = hashcode(this, key);
+
+    pair_t* new_pair = malloc(sizeof *new_pair);
+    new_pair->key = key;
+    new_pair->val = val;
+    new_pair->next = nullptr;
+
+    pair_t* existing_pair = this->list[hash];
+
+    if (existing_pair == nullptr)
+    {
+        this->list[hash] = new_pair;
+        this->len++;
+
+        if (this->len >= this->cap)
+            expand_hash_map(this);
+
+        return;
+    }
+
+    while (existing_pair->next != nullptr)
+    {
+        if (strcmp(existing_pair->key, key) == 0)
+        {
+            existing_pair->val = val;
+            free(new_pair);
+            return;
+        }
+
+        existing_pair = existing_pair->next;
+    }
+
+    existing_pair->next = new_pair;
+    this->len++;
+
+    if (this->len >= this->cap)
+        expand_hash_map(this);
+}
+
+void expand_hash_map(hashmap_t* this)
+{
+    const unsigned int old_cap = this->cap;
+    pair_t** old_list = this->list;
+
+    this->cap *= 2;
+    this->len = 0;
+    this->list = calloc(this->cap, sizeof(pair_t*));
+
+    for (int i = 0; i < old_cap; i++)
+    {
+        pair_t* iter = old_list[i];
+        while (iter != nullptr)
+        {
+            set(this, iter->key, iter->val);
+            pair_t* prev_iter = iter;
+            iter = iter->next;
+            free(prev_iter);
+        }
+    }
+
+    free(old_list);
+}
+
+void free_hash_map(const hashmap_t* this)
+{
+    for (int i = 0; i < this->cap; i++)
+    {
+        pair_t* iter = this->list[i];
+        while (iter != nullptr)
+        {
+            pair_t* prev_iter = iter;
+            iter = iter->next;
+            free(prev_iter->key);
+            free(prev_iter->val);
+            free(prev_iter);
+        }
+    }
+
+    free(this->list);
+}

src/utils/hashmap.h

@@ -0,0 +1,30 @@
+//
+// Created by nazar on 13.09.2025.
+//
+
+#ifndef SIMPLEHTTPSERVER_HASHMAP_H
+#define SIMPLEHTTPSERVER_HASHMAP_H
+
+#include <stdlib.h>
+#define DEFAULT_CAPACITY 8
+
+typedef struct pair {
+    char* key;
+    char* val;
+    struct pair* next;
+} pair_t;
+
+typedef struct hashmap {
+    pair_t** list;
+    unsigned int cap;
+    unsigned int len;
+} hashmap_t;
+
+hashmap_t* new_hash_map();
+unsigned int hashcode(const hashmap_t* this, const char* key);
+char* get(const hashmap_t* this, const char* key);
+void set(hashmap_t* this, char* key, char* val);
+void expand_hash_map(hashmap_t* this);
+void free_hash_map(const hashmap_t* this);
+
+#endif //SIMPLEHTTPSERVER_HASHMAP_H