http_client.c

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/*
 * http_client - HTTP client
 * 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_client.h"


#define HTTP_CLIENT_TIMEOUT 30


struct http_client {
        struct sockaddr_in dst;
        int sd;
        struct wpabuf *req;
        size_t req_pos;
        size_t max_response;

        void (*cb)(void *ctx, struct http_client *c,
                   enum http_client_event event);
        void *cb_ctx;
        struct httpread *hread;
        struct wpabuf body;
};


static void http_client_timeout(void *eloop_data, void *user_ctx)
{
        struct http_client *c = eloop_data;
        wpa_printf(MSG_DEBUG, "HTTP: Timeout");
        c->cb(c->cb_ctx, c, HTTP_CLIENT_TIMEOUT);
}


static void http_client_got_response(struct httpread *handle, void *cookie,
                                     enum httpread_event e)
{
        struct http_client *c = cookie;

        eloop_cancel_timeout(http_client_timeout, c, NULL);
        switch (e) {
        case HTTPREAD_EVENT_FILE_READY:
                if (httpread_hdr_type_get(c->hread) == HTTPREAD_HDR_TYPE_REPLY)
                {
                        int reply_code = httpread_reply_code_get(c->hread);
                        if (reply_code == 200 /* OK */) {
                                wpa_printf(MSG_DEBUG, "HTTP: Response OK from "
                                           "%s:%d",
                                           inet_ntoa(c->dst.sin_addr),
                                           ntohs(c->dst.sin_port));
                                c->cb(c->cb_ctx, c, HTTP_CLIENT_OK);
                        } else {
                                wpa_printf(MSG_DEBUG, "HTTP: Error %d from "
                                           "%s:%d", reply_code,
                                           inet_ntoa(c->dst.sin_addr),
                                           ntohs(c->dst.sin_port));
                                c->cb(c->cb_ctx, c, HTTP_CLIENT_INVALID_REPLY);
                        }
                } else
                        c->cb(c->cb_ctx, c, HTTP_CLIENT_INVALID_REPLY);
                break;
        case HTTPREAD_EVENT_TIMEOUT:
                c->cb(c->cb_ctx, c, HTTP_CLIENT_TIMEOUT);
                break;
        case HTTPREAD_EVENT_ERROR:
                c->cb(c->cb_ctx, c, HTTP_CLIENT_FAILED);
                break;
        }
}


static void http_client_tx_ready(int sock, void *eloop_ctx, void *sock_ctx)
{
        struct http_client *c = eloop_ctx;
        int res;

        wpa_printf(MSG_DEBUG, "HTTP: Send client request to %s:%d (%lu of %lu "
                   "bytes remaining)",
                   inet_ntoa(c->dst.sin_addr), ntohs(c->dst.sin_port),
                   (unsigned long) wpabuf_len(c->req),
                   (unsigned long) wpabuf_len(c->req) - c->req_pos);

        res = send(c->sd, wpabuf_head(c->req) + c->req_pos,
                   wpabuf_len(c->req) - c->req_pos, 0);
        if (res < 0) {
                wpa_printf(MSG_DEBUG, "HTTP: Failed to send buffer: %s",
                           strerror(errno));
                eloop_unregister_sock(c->sd, EVENT_TYPE_WRITE);
                c->cb(c->cb_ctx, c, HTTP_CLIENT_FAILED);
                return;
        }

        if ((size_t) res < wpabuf_len(c->req) - c->req_pos) {
                wpa_printf(MSG_DEBUG, "HTTP: Sent %d of %lu bytes; %lu bytes "
                           "remaining",
                           res, (unsigned long) wpabuf_len(c->req),
                           (unsigned long) wpabuf_len(c->req) - c->req_pos -
                           res);
                c->req_pos += res;
                return;
        }

        wpa_printf(MSG_DEBUG, "HTTP: Full client request sent to %s:%d",
                   inet_ntoa(c->dst.sin_addr), ntohs(c->dst.sin_port));
        eloop_unregister_sock(c->sd, EVENT_TYPE_WRITE);
        wpabuf_free(c->req);
        c->req = NULL;

        c->hread = httpread_create(c->sd, http_client_got_response, c,
                                   c->max_response, HTTP_CLIENT_TIMEOUT);
        if (c->hread == NULL) {
                c->cb(c->cb_ctx, c, HTTP_CLIENT_FAILED);
                return;
        }
}


struct http_client * http_client_addr(struct sockaddr_in *dst,
                                      struct wpabuf *req, size_t max_response,
                                      void (*cb)(void *ctx,
                                                 struct http_client *c,
                                                 enum http_client_event event),
                                      void *cb_ctx)
{
        struct http_client *c;

        c = os_zalloc(sizeof(*c));
        if (c == NULL)
                return NULL;
        c->sd = -1;
        c->dst = *dst;
        c->max_response = max_response;
        c->cb = cb;
        c->cb_ctx = cb_ctx;

        c->sd = socket(AF_INET, SOCK_STREAM, 0);
        if (c->sd < 0) {
                http_client_free(c);
                return NULL;
        }

        if (fcntl(c->sd, F_SETFL, O_NONBLOCK) != 0) {
                wpa_printf(MSG_DEBUG, "HTTP: fnctl(O_NONBLOCK) failed: %s",
                           strerror(errno));
                http_client_free(c);
                return NULL;
        }

        if (connect(c->sd, (struct sockaddr *) dst, sizeof(*dst))) {
                if (errno != EINPROGRESS) {
                        wpa_printf(MSG_DEBUG, "HTTP: Failed to connect: %s",
                                   strerror(errno));
                        http_client_free(c);
                        return NULL;
                }

                /*
                 * Continue connecting in the background; eloop will call us
                 * once the connection is ready (or failed).
                 */
        }

        if (eloop_register_sock(c->sd, EVENT_TYPE_WRITE, http_client_tx_ready,
                                c, NULL)) {
                http_client_free(c);
                return NULL;
        }

        if (eloop_register_timeout(HTTP_CLIENT_TIMEOUT, 0, http_client_timeout,
                                   c, NULL)) {
                http_client_free(c);
                return NULL;
        }

        c->req = req;

        return c;
}


char * http_client_url_parse(const char *url, struct sockaddr_in *dst,
                             char **ret_path)
{
        char *u, *addr, *port, *path;

        u = os_strdup(url);
        if (u == NULL)
                return NULL;

        os_memset(dst, 0, sizeof(*dst));
        dst->sin_family = AF_INET;
        addr = u + 7;
        path = os_strchr(addr, '/');
        port = os_strchr(addr, ':');
        if (path == NULL) {
                path = "/";
        } else {
                *path = '\0'; /* temporary nul termination for address */
                if (port > path)
                        port = NULL;
        }
        if (port)
                *port++ = '\0';

        if (inet_aton(addr, &dst->sin_addr) == 0) {
                /* TODO: name lookup */
                wpa_printf(MSG_DEBUG, "HTTP: Unsupported address in URL '%s' "
                           "(addr='%s' port='%s')",
                           url, addr, port);
                os_free(u);
                return NULL;
        }

        if (port)
                dst->sin_port = htons(atoi(port));
        else
                dst->sin_port = htons(80);

        if (*path == '\0') {
                /* remove temporary nul termination for address */
                *path = '/';
        }

        *ret_path = path;

        return u;
}


struct http_client * http_client_url(const char *url,
                                     struct wpabuf *req, size_t max_response,
                                     void (*cb)(void *ctx,
                                                struct http_client *c,
                                                enum http_client_event event),
                                     void *cb_ctx)
{
        struct sockaddr_in dst;
        struct http_client *c;
        char *u, *path;
        struct wpabuf *req_buf = NULL;

        if (os_strncmp(url, "http://", 7) != 0)
                return NULL;
        u = http_client_url_parse(url, &dst, &path);
        if (u == NULL)
                return NULL;

        if (req == NULL) {
                req_buf = wpabuf_alloc(os_strlen(url) + 1000);
                if (req_buf == NULL) {
                        os_free(u);
                        return NULL;
                }
                req = req_buf;
                wpabuf_printf(req,
                              "GET %s HTTP/1.1\r\n"
                              "Cache-Control: no-cache\r\n"
                              "Pragma: no-cache\r\n"
                              "Accept: text/xml, application/xml\r\n"
                              "User-Agent: wpa_supplicant\r\n"
                              "Host: %s:%d\r\n"
                              "\r\n",
                              path, inet_ntoa(dst.sin_addr),
                              ntohs(dst.sin_port));
        }
        os_free(u);

        c = http_client_addr(&dst, req, max_response, cb, cb_ctx);
        if (c == NULL) {
                wpabuf_free(req_buf);
                return NULL;
        }

        return c;
}


void http_client_free(struct http_client *c)
{
        if (c == NULL)
                return;
        httpread_destroy(c->hread);
        wpabuf_free(c->req);
        if (c->sd >= 0) {
                eloop_unregister_sock(c->sd, EVENT_TYPE_WRITE);
                close(c->sd);
        }
        eloop_cancel_timeout(http_client_timeout, c, NULL);
        os_free(c);
}


struct wpabuf * http_client_get_body(struct http_client *c)
{
        if (c->hread == NULL)
                return NULL;
        wpabuf_set(&c->body, httpread_data_get(c->hread),
                   httpread_length_get(c->hread));
        return &c->body;
}


char * http_client_get_hdr_line(struct http_client *c, const char *tag)
{
        if (c->hread == NULL)
                return NULL;
        return httpread_hdr_line_get(c->hread, tag);
}


char * http_link_update(char *url, const char *base)
{
        char *n;
        size_t len;
        const char *pos;

        /* RFC 2396, Chapter 5.2 */
        /* TODO: consider adding all cases described in RFC 2396 */

        if (url == NULL)
                return NULL;

        if (os_strncmp(url, "http://", 7) == 0)
                return url; /* absolute link */

        if (os_strncmp(base, "http://", 7) != 0)
                return url; /* unable to handle base URL */

        len = os_strlen(url) + 1 + os_strlen(base) + 1;
        n = os_malloc(len);
        if (n == NULL)
                return url; /* failed */

        if (url[0] == '/') {
                pos = os_strchr(base + 7, '/');
                if (pos == NULL) {
                        os_snprintf(n, len, "%s%s", base, url);
                } else {
                        os_memcpy(n, base, pos - base);
                        os_memcpy(n + (pos - base), url, os_strlen(url) + 1);
                }
        } else {
                pos = os_strrchr(base + 7, '/');
                if (pos == NULL) {
                        os_snprintf(n, len, "%s/%s", base, url);
                } else {
                        os_memcpy(n, base, pos - base + 1);
                        os_memcpy(n + (pos - base) + 1, url, os_strlen(url) +
                                  1);
                }
        }

        os_free(url);

        return n;
}