simple_http.c

/**
 * MIT License
 *
 * Copyright (c) 2012 Gabriel Parmer
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <string.h>
#include <assert.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>

#include <simple_http.h>

struct http_req *
shttp_alloc_req(int fd, char *request)
{
	struct http_req *r;
	assert(request);

	r = malloc(sizeof(struct http_req));
	if (!r) return NULL;
	memset(r, 0, sizeof(struct http_req));

	r->request = request;
	r->req_len = strlen(request);
	r->path = NULL;
	r->fd = fd;

	return r;
}

void
shttp_free_req(struct http_req *r)
{
	r->path = NULL;
	if (r->request)   free(r->request);
	if (r->response)  free(r->response);
	if (r->resp_head) free(r->resp_head);
	close(r->fd);
	free(r);
}

static inline char *
find_whitespace(char *s)
{
	assert(s);
	while (*s != ' ' && *s != '\0') s++;
	return s;
}

/*
 * Pass in the request.  Set the ->path field in r to point to the
 * path that is being requested.
 */
int
shttp_get_path(struct http_req *r)
{
	char *curr, *end, *path;

	assert(r);
	assert(r->request);

	if (strncmp(r->request, "GET ", strlen("GET "))) return -1;
	path = curr = r->request + sizeof("GET ")-1;

	end = find_whitespace(curr);
	if (*end == '\0') return -1;
	*end = '\0';

	if (*path == '/') path++;
	r->path = path;

	return 0;
}

static const char success_head[] =
	"HTTP/1.1 200 OK\r\n"
	"Date: Sat, 14 Feb 2008 14:59:00 GMT\r\n"
	"Connection: close\r\n"
	"Content-Length: ";
#define MAX_DIGITS 128

/*
 * Creates the ->response field in r that includes "answer", but also
 * includes other data.
 */
int
shttp_alloc_response_head(struct http_req *r, char *data, int dlen)
{
	int  head_sz, pre_sz, len_sz;
	char len_str[MAX_DIGITS];
	char *resp_hd;

	r->response = data;
	r->resp_len = dlen;

	len_sz  = snprintf(len_str, MAX_DIGITS, "%d\r\n\r\n", r->resp_len);
	if (len_sz < 1) return -1;

	pre_sz  = strlen(success_head);
	assert(pre_sz > 0);
	head_sz = pre_sz + len_sz;
	assert(head_sz > 0);
	resp_hd = malloc(head_sz);
	if (!resp_hd)   return -1;

	r->resp_head   = resp_hd;
	r->resp_hd_len = head_sz;

	memcpy(resp_hd, success_head, pre_sz);
	memcpy(resp_hd + pre_sz, len_str, len_sz);

	return 0;
}