/*
  * TLS/SSL Protocol
  * Copyright (c) 2011 Martin Storsjo
  *
  * This file is part of Libav.
  *
  * Libav is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * Libav is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include "avformat.h"
 #include "url.h"
 #include "libavutil/avstring.h"
 #if CONFIG_GNUTLS
 #include <gnutls/gnutls.h>
 #define TLS_read(c, buf, size)  gnutls_record_recv(c->session, buf, size)
 #define TLS_write(c, buf, size) gnutls_record_send(c->session, buf, size)
 #define TLS_shutdown(c)         gnutls_bye(c->session, GNUTLS_SHUT_RDWR)
 #define TLS_free(c) do { \
         if (c->session) \
             gnutls_deinit(c->session); \
         if (c->cred) \
             gnutls_certificate_free_credentials(c->cred); \
     } while (0)
 #elif CONFIG_OPENSSL
 #include <openssl/bio.h>
 #include <openssl/ssl.h>
 #include <openssl/err.h>
 #define TLS_read(c, buf, size)  SSL_read(c->ssl,  buf, size)
 #define TLS_write(c, buf, size) SSL_write(c->ssl, buf, size)
 #define TLS_shutdown(c)         SSL_shutdown(c->ssl)
 #define TLS_free(c) do { \
         if (c->ssl) \
             SSL_free(c->ssl); \
         if (c->ctx) \
             SSL_CTX_free(c->ctx); \
     } while (0)
 #endif
 #include "network.h"
 #include "os_support.h"
 #include "internal.h"
 #if HAVE_POLL_H
 #include <poll.h>
 #endif
 
 typedef struct {
     const AVClass *class;
     URLContext *tcp;
 #if CONFIG_GNUTLS
     gnutls_session_t session;
     gnutls_certificate_credentials_t cred;
 #elif CONFIG_OPENSSL
     SSL_CTX *ctx;
     SSL *ssl;
 #endif
     int fd;
 } TLSContext;
 
 static int do_tls_poll(URLContext *h, int ret)
 {
     TLSContext *c = h->priv_data;
     struct pollfd p = { c->fd, 0, 0 };
 #if CONFIG_GNUTLS
     if (ret != GNUTLS_E_AGAIN && ret != GNUTLS_E_INTERRUPTED) {

         av_log(h, AV_LOG_ERROR, "%s\n", gnutls_strerror(ret));

         return AVERROR(EIO);
     }
     if (gnutls_record_get_direction(c->session))
         p.events = POLLOUT;
     else
         p.events = POLLIN;
 #elif CONFIG_OPENSSL
     ret = SSL_get_error(c->ssl, ret);
     if (ret == SSL_ERROR_WANT_READ) {
         p.events = POLLIN;
     } else if (ret == SSL_ERROR_WANT_WRITE) {
         p.events = POLLOUT;
     } else {

         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));

         return AVERROR(EIO);
     }
 #endif

     if (h->flags & AVIO_FLAG_NONBLOCK)

         return AVERROR(EAGAIN);
     while (1) {
         int n = poll(&p, 1, 100);
         if (n > 0)
             break;

         if (ff_check_interrupt(&h->interrupt_callback))

             return AVERROR(EINTR);
     }
     return 0;
 }
 
 static int tls_open(URLContext *h, const char *uri, int flags)
 {
     TLSContext *c = h->priv_data;
     int ret;
     int port;
     char buf[200], host[200];
     int numerichost = 0;
     struct addrinfo hints = { 0 }, *ai = NULL;

     const char *proxy_path;
     int use_proxy;

 
     ff_tls_init();
 

     proxy_path = getenv("http_proxy");
     use_proxy = (proxy_path != NULL) && !getenv("no_proxy") &&
         av_strstart(proxy_path, "http://", NULL);
 

     av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, NULL, 0, uri);
     ff_url_join(buf, sizeof(buf), "tcp", NULL, host, port, NULL);
 
     hints.ai_flags = AI_NUMERICHOST;
     if (!getaddrinfo(host, NULL, &hints, &ai)) {
         numerichost = 1;
         freeaddrinfo(ai);
     }
 

     if (use_proxy) {
         char proxy_host[200], proxy_auth[200], dest[200];
         int proxy_port;
         av_url_split(NULL, 0, proxy_auth, sizeof(proxy_auth),
                      proxy_host, sizeof(proxy_host), &proxy_port, NULL, 0,
                      proxy_path);
         ff_url_join(dest, sizeof(dest), NULL, NULL, host, port, NULL);
         ff_url_join(buf, sizeof(buf), "httpproxy", proxy_auth, proxy_host,
                     proxy_port, "/%s", dest);
     }
 

     ret = ffurl_open(&c->tcp, buf, AVIO_FLAG_READ_WRITE,
                      &h->interrupt_callback, NULL);

     if (ret)
         goto fail;
     c->fd = ffurl_get_file_handle(c->tcp);
 
 #if CONFIG_GNUTLS
     gnutls_init(&c->session, GNUTLS_CLIENT);
     if (!numerichost)
         gnutls_server_name_set(c->session, GNUTLS_NAME_DNS, host, strlen(host));
     gnutls_certificate_allocate_credentials(&c->cred);
     gnutls_certificate_set_verify_flags(c->cred, 0);
     gnutls_credentials_set(c->session, GNUTLS_CRD_CERTIFICATE, c->cred);
     gnutls_transport_set_ptr(c->session, (gnutls_transport_ptr_t)
                                          (intptr_t) c->fd);
     gnutls_priority_set_direct(c->session, "NORMAL", NULL);
     while (1) {
         ret = gnutls_handshake(c->session);
         if (ret == 0)
             break;
         if ((ret = do_tls_poll(h, ret)) < 0)
             goto fail;
     }
 #elif CONFIG_OPENSSL

     c->ctx = SSL_CTX_new(TLSv1_client_method());

     if (!c->ctx) {

         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));

         ret = AVERROR(EIO);
         goto fail;
     }
     c->ssl = SSL_new(c->ctx);
     if (!c->ssl) {

         av_log(h, AV_LOG_ERROR, "%s\n", ERR_error_string(ERR_get_error(), NULL));

         ret = AVERROR(EIO);
         goto fail;
     }
     SSL_set_fd(c->ssl, c->fd);
     if (!numerichost)
         SSL_set_tlsext_host_name(c->ssl, host);
     while (1) {
         ret = SSL_connect(c->ssl);
         if (ret > 0)
             break;
         if (ret == 0) {

             av_log(h, AV_LOG_ERROR, "Unable to negotiate TLS/SSL session\n");

             ret = AVERROR(EIO);
             goto fail;
         }
         if ((ret = do_tls_poll(h, ret)) < 0)
             goto fail;
     }
 #endif
     return 0;
 fail:
     TLS_free(c);
     if (c->tcp)
         ffurl_close(c->tcp);
     ff_tls_deinit();
     return ret;
 }
 
 static int tls_read(URLContext *h, uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     while (1) {
         int ret = TLS_read(c, buf, size);
         if (ret > 0)
             return ret;
         if (ret == 0)
             return AVERROR(EIO);
         if ((ret = do_tls_poll(h, ret)) < 0)
             return ret;
     }
     return 0;
 }
 
 static int tls_write(URLContext *h, const uint8_t *buf, int size)
 {
     TLSContext *c = h->priv_data;
     while (1) {
         int ret = TLS_write(c, buf, size);
         if (ret > 0)
             return ret;
         if (ret == 0)
             return AVERROR(EIO);
         if ((ret = do_tls_poll(h, ret)) < 0)
             return ret;
     }
     return 0;
 }
 
 static int tls_close(URLContext *h)
 {
     TLSContext *c = h->priv_data;
     TLS_shutdown(c);
     TLS_free(c);
     ffurl_close(c->tcp);
     ff_tls_deinit();
     return 0;
 }
 
 URLProtocol ff_tls_protocol = {
     .name           = "tls",
     .url_open       = tls_open,
     .url_read       = tls_read,
     .url_write      = tls_write,
     .url_close      = tls_close,
     .priv_data_size = sizeof(TLSContext),

     .flags          = URL_PROTOCOL_FLAG_NETWORK,

 };