From 82fcab1848bfc1526927580e4fd2a91c5411581f Mon Sep 17 00:00:00 2001
From: Santo Cariotti <santo@dcariotti.me>
Date: Fri, 22 Oct 2021 21:07:37 +0200
Subject: read the file to the client

---
 Year_3/TSDWL/webserver/server.c | 64 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/Year_3/TSDWL/webserver/server.c b/Year_3/TSDWL/webserver/server.c
index e2f6a3e..5eedf70 100644
--- a/Year_3/TSDWL/webserver/server.c
+++ b/Year_3/TSDWL/webserver/server.c
@@ -3,11 +3,14 @@
  * [1] https://it.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Richiesta_GET_e_risposta_di_successo
  */
 #include <arpa/inet.h>
+#include <fcntl.h>
 #include <netinet/in.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
 #include <unistd.h>
 
 #define DEFAULT_WWW "./www"
@@ -109,6 +112,10 @@ parse_first_line(request_t* request, char* header, size_t len)
             break;
         }
         case 1: {
+            if (token[0] != '/') {
+                fprintf(stderr, "'%s' must starts with a '/'\n", token);
+                goto parse_error;
+            }
             strcpy(request->path, token);
             break;
         }
@@ -142,6 +149,57 @@ parse_error:
     return -1;
 }
 
+void
+read_file(char* root, char* file, int client)
+{
+    /* FIXME: In Linux the max name length is 255, but here we include the 
+     * root, and I don't want to use an array of 511 bytes (255*2+1). So I am
+     * supposing a max path of 300 chars. */
+    char path[300];
+    char buffer[1024];
+    int n;
+    int fd;
+    int root_len;
+    int file_len;
+
+    root_len = strlen(root);
+    file_len = strlen(file);
+
+    if (root[root_len - 1] == '/') {
+        root_len--;
+    }
+
+    /* Considers this kind of path like `/index.html` */
+    if (file_len == 1) {
+        file = "/index.html";
+        file_len = strlen(file);
+    }
+
+    strncpy(path, root, root_len);
+    strncpy(path + root_len, file, file_len);
+
+    if ((fd = open(path, O_RDONLY)) == -1) {
+        strcpy(buffer, "Error opening the file on server");
+
+        /* Write the error to the client and also to the server */
+        write(client, buffer, strlen(buffer) + 1);
+        perror(buffer);
+        return;
+    }
+
+    while ((n = read(fd, buffer, sizeof(buffer))) != 0) {
+        if (n == -1) {
+            perror("Error reading the file");
+            break;
+        }
+
+        buffer[n] = '\0';
+        write(client, buffer, strlen(buffer) + 1);
+    }
+
+    close(fd);
+}
+
 int
 main(int argc, char* argv[])
 {
@@ -203,7 +261,11 @@ main(int argc, char* argv[])
             write(clientfd, buffer, strlen(buffer) + 1);
         }
 
-        parse_first_line(&request, headers[0], strlen(headers[0]));
+        if (parse_first_line(&request, headers[0], strlen(headers[0])) > -1) {
+            if (request.method == GET) {
+                read_file(www_path, request.path, clientfd);
+            }
+        }
 
         for (i = 0; i < headers_num; ++i) {
             free(headers + i);
-- 
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