Create HTTP\exams\2024-02-24

imAlessas · Jun 30, 2024 · 1c120aa · 1c120aa
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diff --git a/HTTP/exams/2024-02-24/guidelines.pdf b/HTTP/exams/2024-02-24/guidelines.pdf
diff --git a/HTTP/exams/2024-02-24/web-server.c b/HTTP/exams/2024-02-24/web-server.c
@@ -0,0 +1,203 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+
+
+
+struct char_map{
+    char * key;
+    char * value;
+};
+
+
+
+
+int main() {
+
+    const int PORT = 9278;
+    const char CRLF[] = "\r\n";
+
+
+    // local variable definition
+    int s, s_double;                        // socket
+    int t;                                  // temporary variable
+    struct sockaddr_in server_address;
+    struct sockaddr_in client_address;
+    char buffer[10 * 1024];                 // generic buffer
+    struct char_map headers[100];           // will contain the parsed headers
+    char * command_line;                    // first line of the request
+    int i;                                  // generic index
+
+
+
+
+    // create socket
+    s = socket( AF_INET, SOCK_STREAM, 0 );
+
+    // terminate if error
+    if(s == -1) {
+        perror("socket() failed");
+        return 1;
+    }
+
+
+    // set up the server address
+    server_address.sin_family = AF_INET;
+    server_address.sin_port = htons(PORT);
+    server_address.sin_addr.s_addr = 0;
+
+
+    // bind socket with server address
+    t = bind(s, (struct sockaddr *) &server_address, sizeof(struct sockaddr_in));
+
+    // terminate if error
+    if(t == -1){
+        perror("bind() fallita");
+        return 1;
+    }
+
+
+    // put socket s in listen mode
+    t = listen(s, 5);
+
+    // terminate if error
+    if(t == -1){
+        perror("listen() fallita");
+        return 1;
+    }
+
+
+    // start server
+    int address_length = sizeof(struct sockaddr);
+
+
+    while(1) {
+
+        // dequeue the backlog and process the request into a new socket
+        s_double = accept(s, (struct sockaddr *) &client_address, &address_length);
+
+        if(fork()) continue;
+
+        // terminate if error
+        if(s_double == -1) {
+            perror("socket() failed");
+            return 1;
+        }
+
+        command_line = headers[0].key = buffer;
+        int lines = 0;
+
+        for( i = 0; read(s_double, buffer + i, 1); i++) {
+
+            // end of the line
+            if( buffer[i - 1] == '\r' && buffer[i] == '\n'){
+
+                // null-terminate
+                buffer[i - 1] = 0;
+
+                if( headers[lines].key == NULL )
+                    break;
+
+                // set-up new line
+                lines++;
+                headers[lines].key = &buffer[i + 1];
+
+            }
+
+            // endo fo the name, start of the value
+            if( buffer[i] == ':' && headers[lines].value == NULL) {
+
+                // null-terminate
+                buffer[i] = 0;
+
+                // set header value
+                headers[lines].value = &buffer[i + 1];
+
+            }
+
+        }
+
+        // extract important info from command_line
+        char * method, * uri, * version;
+
+        method = command_line;
+        for(i = 0; command_line[i] != ' '; i++);
+        command_line[i++] = 0;
+
+        uri = command_line + i;
+        for(; command_line[i] != ' '; i++);
+        command_line[i++] = 0;
+
+        version = command_line + i;
+        for(; command_line[i] != 0; i++);
+        command_line[i++] = 0;
+
+        for(int i = 0; i < lines; i++)
+            printf("%s ----> %s\n", headers[i].key, headers[i].value);
+        printf("Method ----> %s\nURI ----> %s\nVersion ----> %s\n\n\n", method, uri, version);
+
+
+
+        // display the requested file
+        FILE * file = fopen(uri + 1, "rw");
+
+        if(file == NULL) {
+
+            // create response
+            sprintf(buffer, "HTTP/1.1 404 NOT FOUND\r\n\r\n"
+                            "<html><h1>Could not find %s.<h1></html>", uri);
+
+            // write response
+            write(s_double, buffer, strlen(buffer));
+
+        } else {
+
+            // create response header
+            sprintf(buffer, "HTTP/1.1 200 OK\r\nTransfer-Encoding: chunked\r\n\r\n");
+
+            // write response
+            write(s_double, buffer, strlen(buffer));
+
+            char chunk_size[20];
+
+            while( !feof(file) ){
+
+                // read at most 1Kb from the file
+                fread(buffer, 1, 1024, file);
+
+                // get first line of the response
+                sprintf(chunk_size, "%x\r\n", strlen(buffer));
+
+                // write the first line
+                write(s_double, chunk_size, strlen(chunk_size));
+
+                // write the chunk
+                write(s_double, buffer, strlen(buffer));
+
+                // end of the chunk
+                write(s_double, CRLF, strlen(CRLF));
+
+            }
+
+            // last chunk
+            sprintf(buffer, "0\r\n");
+
+            // write last chunk
+            write(s_double, buffer, strlen(buffer));
+
+
+        }
+
+        // close socket and kill thread
+        close(s_double);
+        exit(1);
+
+    }
+
+
+    return 0; 
+
+} // main