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/* An example of the work of this file is showed at [1]
*
* [1] https://it.wikipedia.org/wiki/Hypertext_Transfer_Protocol#Richiesta_GET_e_risposta_di_successo
*/
#include <arpa/inet.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <unistd.h>
#define DEFAULT_WWW "./www"
typedef enum {
GET,
/* TODO: types below */
HEAD,
OPTIONS,
POST,
PUT,
PATCH,
DELETE
} methods;
typedef enum {
/* Some of the HTTP versions defined at [1]
*
* [1] https://en.wikipedia.org/wiki/Hypertext_Transfer_Protocol#History
*/
HTTP1, /* HTTP/1.0 */
HTTP1_1, /* HTTP/1.1 */
HTTP2, /* HTTP/2 */
} http_t;
typedef struct {
methods method;
char path[256]; /* FIXME: handle path with more than 256 chars */
http_t http_version;
} request_t;
/* TODO: Make the parsing of headers */
void
read_headers(int* fd, char** headers, int* headers_num)
{
char ch;
int flag_read; /* Used to check the return value of `read` function */
unsigned i;
char buffer[1024];
*headers_num = 0;
while (1) {
i = 0;
buffer[0] = '\0';
headers[*headers_num] = malloc(sizeof(char) * 1024);
while ((flag_read = read(*fd, &ch, 1)) != 0) {
if (flag_read == -1) {
perror("Error reading the headers");
exit(1);
}
buffer[i] = ch;
if (ch == '\n' && (i < 1 || buffer[i - 1] == '\r')) {
break;
}
i++;
}
buffer[i - 1] = '\0';
if (i < 2) {
break;
}
memcpy(headers[*headers_num], buffer, i);
(*headers_num)++;
}
}
void
get_client_ip(int fd, char* buffer)
{
struct sockaddr_in addr;
socklen_t addr_size = sizeof(struct sockaddr_in);
getpeername(fd, (struct sockaddr*)&addr, &addr_size);
strcpy(buffer, inet_ntoa(addr.sin_addr));
}
int
parse_first_line(request_t* request, char* header, size_t len)
{
char* token;
int i;
i = 0;
token = strtok(header, " ");
do {
switch (i) {
case 0: {
if (strcmp(token, "GET") == 0) {
request->method = GET;
} else {
fprintf(stderr, "'%s' method not supported\n", token);
goto parse_error;
}
/* TODO: Handle the other HTTP methods */
break;
}
case 1: {
strcpy(request->path, token);
break;
}
case 2: {
if (strcmp(token, "HTTP/1.0") == 0) {
request->http_version = HTTP1;
} else if (strcmp(token, "HTTP/1.1") == 0) {
request->http_version = HTTP1_1;
} else if (strcmp(token, "HTTP/2") == 0) {
request->http_version = HTTP2;
} else {
fprintf(stderr, "'%s' version not supported\n", token);
goto parse_error;
}
break;
}
/* If it comes here, it means that the header have more than 3 tokens */
default: {
fprintf(stderr, "Header does not have a valid syntax\n");
goto parse_error;
}
}
i++;
token = strtok(NULL, " ");
} while (token != NULL);
return 0;
parse_error:
return -1;
}
int
main(int argc, char* argv[])
{
char* www_path;
char** headers;
int headers_num;
unsigned i;
int sockfd, clientfd;
struct sockaddr_in address;
char client_ip[20];
socklen_t address_len;
char* buffer;
request_t request;
if (argc < 2) {
fprintf(stderr, "Usage: %s <port> [root_path]", argv[0]);
exit(1);
}
www_path = (argc >= 3) ? argv[2] : DEFAULT_WWW;
/* Max 24 headers for now on the stack */
headers = malloc(sizeof(char*) * 24);
if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
perror("Error creating a new socket");
exit(1);
}
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(atoi(argv[1]));
address.sin_family = AF_INET;
address_len = sizeof(address);
if (bind(sockfd, (struct sockaddr*)&address, address_len) == -1) {
perror("Error binding the socket");
exit(1);
}
if (listen(sockfd, 1) == -1) {
perror("Unable to listen");
exit(1);
}
while (1) {
if ((clientfd = accept(sockfd, (struct sockaddr*)&address, &address_len)) == -1) {
perror("Error with client connection, maybe try again later");
continue;
}
get_client_ip(clientfd, client_ip);
printf("Connection from '%s':\n", client_ip);
read_headers(&clientfd, headers, &headers_num);
if (headers_num == 0) {
buffer = "You must specify almost one header\n";
write(clientfd, buffer, strlen(buffer) + 1);
}
parse_first_line(&request, headers[0], strlen(headers[0]));
for (i = 0; i < headers_num; ++i) {
free(headers + i);
}
printf("[Connection closed]\n\n");
close(clientfd);
}
close(sockfd);
return 0;
}
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