http_server.c

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/*
 * http_server - HTTP server
 * Copyright (c) 2009, Jouni Malinen <j@w1.fi>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include "includes.h"
#include <fcntl.h>

#include "common.h"
#include "eloop.h"
#include "httpread.h"
#include "http_server.h"

#define HTTP_SERVER_TIMEOUT 30
#define HTTP_SERVER_MAX_REQ_LEN 8000
#define HTTP_SERVER_MAX_CONNECTIONS 10

struct http_request {
        struct http_request *next;
        struct http_server *srv;
        int fd;
        struct sockaddr_in cli;
        struct httpread *hread;
};

struct http_server {
        void (*cb)(void *ctx, struct http_request *req);
        void *cb_ctx;

        int fd;
        int port;

        struct http_request *requests;
        unsigned int request_count;
};


static void http_request_cb(struct httpread *handle, void *cookie,
                            enum httpread_event en)
{
        struct http_request *req = cookie;
        struct http_server *srv = req->srv;

        if (en == HTTPREAD_EVENT_FILE_READY) {
                wpa_printf(MSG_DEBUG, "HTTP: Request from %s:%d received",
                           inet_ntoa(req->cli.sin_addr),
                           ntohs(req->cli.sin_port));
                srv->cb(srv->cb_ctx, req);
                return;
        }
        wpa_printf(MSG_DEBUG, "HTTP: Request from %s:%d could not be received "
                   "completely", inet_ntoa(req->cli.sin_addr),
                   ntohs(req->cli.sin_port));
        http_request_deinit(req);
}


static struct http_request * http_request_init(struct http_server *srv, int fd,
                                               struct sockaddr_in *cli)
{
        struct http_request *req;

        if (srv->request_count >= HTTP_SERVER_MAX_CONNECTIONS) {
                wpa_printf(MSG_DEBUG, "HTTP: Too many concurrent requests");
                return NULL;
        }

        req = os_zalloc(sizeof(*req));
        if (req == NULL)
                return NULL;

        req->srv = srv;
        req->fd = fd;
        req->cli = *cli;

        req->hread = httpread_create(req->fd, http_request_cb, req,
                                     HTTP_SERVER_MAX_REQ_LEN,
                                     HTTP_SERVER_TIMEOUT);
        if (req->hread == NULL) {
                http_request_deinit(req);
                return NULL;
        }

        return req;
}


void http_request_deinit(struct http_request *req)
{
        struct http_request *r, *p;
        struct http_server *srv;

        if (req == NULL)
                return;

        srv = req->srv;
        p = NULL;
        r = srv->requests;
        while (r) {
                if (r == req) {
                        if (p)
                                p->next = r->next;
                        else
                                srv->requests = r->next;
                        srv->request_count--;
                        break;
                }
                p = r;
                r = r->next;
        }

        httpread_destroy(req->hread);
        close(req->fd);
        os_free(req);
}


static void http_request_free_all(struct http_request *req)
{
        struct http_request *prev;
        while (req) {
                prev = req;
                req = req->next;
                http_request_deinit(prev);
        }
}


void http_request_send(struct http_request *req, struct wpabuf *resp)
{
        int res;

        wpa_printf(MSG_DEBUG, "HTTP: Send %lu byte response to %s:%d",
                   (unsigned long) wpabuf_len(resp),
                   inet_ntoa(req->cli.sin_addr),
                   ntohs(req->cli.sin_port));

        res = send(req->fd, wpabuf_head(resp), wpabuf_len(resp), 0);
        if (res < 0) {
                wpa_printf(MSG_DEBUG, "HTTP: Send failed: %s",
                           strerror(errno));
        } else if ((size_t) res < wpabuf_len(resp)) {
                wpa_printf(MSG_DEBUG, "HTTP: Sent only %d of %lu bytes",
                           res, (unsigned long) wpabuf_len(resp));
                /* TODO: add eloop handler for sending rest of the data */
        }

        wpabuf_free(resp);
}


void http_request_send_and_deinit(struct http_request *req,
                                  struct wpabuf *resp)
{
        http_request_send(req, resp);
        http_request_deinit(req);
}


enum httpread_hdr_type http_request_get_type(struct http_request *req)
{
        return httpread_hdr_type_get(req->hread);
}


char * http_request_get_uri(struct http_request *req)
{
        return httpread_uri_get(req->hread);
}


char * http_request_get_hdr(struct http_request *req)
{
        return httpread_hdr_get(req->hread);
}


char * http_request_get_data(struct http_request *req)
{
        return httpread_data_get(req->hread);
}


char * http_request_get_hdr_line(struct http_request *req, const char *tag)
{
        return httpread_hdr_line_get(req->hread, tag);
}


struct sockaddr_in * http_request_get_cli_addr(struct http_request *req)
{
        return &req->cli;
}


static void http_server_cb(int sd, void *eloop_ctx, void *sock_ctx)
{
        struct sockaddr_in addr;
        socklen_t addr_len = sizeof(addr);
        struct http_server *srv = eloop_ctx;
        int conn;
        struct http_request *req;

        conn = accept(srv->fd, (struct sockaddr *) &addr, &addr_len);
        if (conn < 0) {
                wpa_printf(MSG_DEBUG, "HTTP: Failed to accept new connection: "
                           "%s", strerror(errno));
                return;
        }
        wpa_printf(MSG_DEBUG, "HTTP: Connection from %s:%d",
                   inet_ntoa(addr.sin_addr), ntohs(addr.sin_port));

        req = http_request_init(srv, conn, &addr);
        if (req == NULL) {
                close(conn);
                return;
        }

        req->next = srv->requests;
        srv->requests = req;
        srv->request_count++;
}


struct http_server * http_server_init(struct in_addr *addr, int port,
                                      void (*cb)(void *ctx,
                                                 struct http_request *req),
                                      void *cb_ctx)
{
        struct sockaddr_in sin;
        struct http_server *srv;

        srv = os_zalloc(sizeof(*srv));
        if (srv == NULL)
                return NULL;
        srv->cb = cb;
        srv->cb_ctx = cb_ctx;

        srv->fd = socket(AF_INET, SOCK_STREAM, 0);
        if (srv->fd < 0)
                goto fail;
        if (fcntl(srv->fd, F_SETFL, O_NONBLOCK) < 0)
                goto fail;
        if (port < 0)
                srv->port = 49152;
        else
                srv->port = port;

        os_memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
        sin.sin_addr.s_addr = addr->s_addr;

        for (;;) {
                sin.sin_port = htons(srv->port);
                if (bind(srv->fd, (struct sockaddr *) &sin, sizeof(sin)) == 0)
                        break;
                if (errno == EADDRINUSE) {
                        /* search for unused port */
                        if (++srv->port == 65535 || port >= 0)
                                goto fail;
                        continue;
                }
                wpa_printf(MSG_DEBUG, "HTTP: Failed to bind server port %d: "
                           "%s", srv->port, strerror(errno));
                goto fail;
        }
        if (listen(srv->fd, 10 /* max backlog */) < 0)
                goto fail;
        if (fcntl(srv->fd, F_SETFL, O_NONBLOCK) < 0)
                goto fail;
        if (eloop_register_sock(srv->fd, EVENT_TYPE_READ, http_server_cb,
                                srv, NULL))
                goto fail;

        wpa_printf(MSG_DEBUG, "HTTP: Started server on %s:%d",
                   inet_ntoa(*addr), srv->port);

        return srv;

fail:
        http_server_deinit(srv);
        return NULL;
}


void http_server_deinit(struct http_server *srv)
{
        if (srv == NULL)
                return;
        if (srv->fd >= 0) {
                eloop_unregister_sock(srv->fd, EVENT_TYPE_READ);
                close(srv->fd);
        }
        http_request_free_all(srv->requests);

        os_free(srv);
}


int http_server_get_port(struct http_server *srv)
{
        return srv->port;
}