tcptls.c File Reference

Code to support TCP and TLS server/client. More...

#include "asterisk.h"
#include <sys/signal.h>
#include "asterisk/compat.h"
#include "asterisk/tcptls.h"
#include "asterisk/http.h"
#include "asterisk/utils.h"
#include "asterisk/strings.h"
#include "asterisk/options.h"
#include "asterisk/manager.h"
#include "asterisk/astobj2.h"

Include dependency graph for tcptls.c:

Go to the source code of this file.

Functions
static int	__ssl_setup (struct ast_tls_config *cfg, int client)
int	ast_ssl_setup (struct ast_tls_config *cfg)
struct ast_tcptls_session_instance *	ast_tcptls_client_create (struct ast_tcptls_session_args *desc)
struct ast_tcptls_session_instance *	ast_tcptls_client_start (struct ast_tcptls_session_instance *tcptls_session)
	attempts to connect and start tcptls session, on error the tcptls_session's ref count is decremented, fd and file are closed, and NULL is returned.
HOOK_T	ast_tcptls_server_read (struct ast_tcptls_session_instance *tcptls_session, void *buf, size_t count)
	replacement read/write functions for SSL support. We use wrappers rather than SSL_read/SSL_write directly so we can put in some debugging.
void *	ast_tcptls_server_root (void *data)
void	ast_tcptls_server_start (struct ast_tcptls_session_args *desc)
	This is a generic (re)start routine for a TCP server, which does the socket/bind/listen and starts a thread for handling accept().
void	ast_tcptls_server_stop (struct ast_tcptls_session_args *desc)
	Shutdown a running server if there is one.
HOOK_T	ast_tcptls_server_write (struct ast_tcptls_session_instance *tcptls_session, void *buf, size_t count)
static void *	handle_tcptls_connection (void *data)
	creates a FILE * from the fd passed by the accept thread. This operation is potentially expensive (certificate verification), so we do it in the child thread context.
static void	session_instance_destructor (void *obj)

---

Detailed Description

Code to support TCP and TLS server/client.

Author:

Luigi Rizzo

Brett Bryant <brettbryant@gmail.com>

Definition in file tcptls.c.

---

Function Documentation

static int __ssl_setup	(	struct ast_tls_config *	cfg,
		int	client
	)			[static]

Definition at line 284 of file tcptls.c.

References ast_debug, ast_strlen_zero(), ast_verb, ast_tls_config::cafile, ast_tls_config::capath, ast_tls_config::certfile, ast_tls_config::cipher, ast_tls_config::enabled, S_OR, and ast_tls_config::ssl_ctx.

Referenced by ast_ssl_setup(), and ast_tcptls_client_start().

{
#ifndef DO_SSL
   cfg->enabled = 0;
   return 0;
#else
   if (!cfg->enabled)
      return 0;

   SSL_load_error_strings();
   SSLeay_add_ssl_algorithms();

   if (!(cfg->ssl_ctx = SSL_CTX_new( client ? SSLv23_client_method() : SSLv23_server_method() ))) {
      ast_debug(1, "Sorry, SSL_CTX_new call returned null...\n");
      cfg->enabled = 0;
      return 0;
   }
   if (!ast_strlen_zero(cfg->certfile)) {
      if (SSL_CTX_use_certificate_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0 ||
          SSL_CTX_use_PrivateKey_file(cfg->ssl_ctx, cfg->certfile, SSL_FILETYPE_PEM) == 0 ||
          SSL_CTX_check_private_key(cfg->ssl_ctx) == 0 ) {
         if (!client) {
            /* Clients don't need a certificate, but if its setup we can use it */
            ast_verb(0, "SSL cert error <%s>", cfg->certfile);
            sleep(2);
            cfg->enabled = 0;
            return 0;
         }
      }
   }
   if (!ast_strlen_zero(cfg->cipher)) {
      if (SSL_CTX_set_cipher_list(cfg->ssl_ctx, cfg->cipher) == 0 ) {
         if (!client) {
            ast_verb(0, "SSL cipher error <%s>", cfg->cipher);
            sleep(2);
            cfg->enabled = 0;
            return 0;
         }
      }
   }
   if (!ast_strlen_zero(cfg->cafile) || !ast_strlen_zero(cfg->capath)) {
      if (SSL_CTX_load_verify_locations(cfg->ssl_ctx, S_OR(cfg->cafile, NULL), S_OR(cfg->capath,NULL)) == 0)
         ast_verb(0, "SSL CA file(%s)/path(%s) error\n", cfg->cafile, cfg->capath);
   }

   ast_verb(0, "SSL certificate ok\n");
   return 1;
#endif
}

int ast_ssl_setup

(

struct ast_tls_config *

cfg

)

Definition at line 334 of file tcptls.c.

References __ssl_setup().

Referenced by __ast_http_load(), __init_manager(), and reload_config().

{
   return __ssl_setup(cfg, 0);
}

struct ast_tcptls_session_instance* ast_tcptls_client_create

(

struct ast_tcptls_session_args *

desc

)

[read]

Definition at line 376 of file tcptls.c.

References ast_tcptls_session_args::accept_fd, ao2_alloc, ao2_ref, ast_debug, ast_inet_ntoa(), ast_log(), ast_mutex_init(), ast_tcptls_session_instance::client, errno, ast_tcptls_session_instance::fd, ast_tcptls_session_args::local_address, ast_tcptls_session_instance::lock, LOG_ERROR, LOG_WARNING, ast_tcptls_session_args::name, ast_tcptls_session_args::old_address, ast_tcptls_session_instance::parent, ast_tcptls_session_instance::remote_address, ast_tcptls_session_args::remote_address, session_instance_destructor(), and ast_tcptls_session_args::worker_fn.

Referenced by app_exec(), and sip_prepare_socket().

{
   int x = 1;
   struct ast_tcptls_session_instance *tcptls_session = NULL;

   /* Do nothing if nothing has changed */
   if (!memcmp(&desc->old_address, &desc->remote_address, sizeof(desc->old_address))) {
      ast_debug(1, "Nothing changed in %s\n", desc->name);
      return NULL;
   }

   desc->old_address = desc->remote_address;

   if (desc->accept_fd != -1)
      close(desc->accept_fd);

   desc->accept_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
   if (desc->accept_fd < 0) {
      ast_log(LOG_WARNING, "Unable to allocate socket for %s: %s\n",
         desc->name, strerror(errno));
      return NULL;
   }

   /* if a local address was specified, bind to it so the connection will
      originate from the desired address */
   if (desc->local_address.sin_family != 0) {
      setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
      if (bind(desc->accept_fd, (struct sockaddr *) &desc->local_address, sizeof(desc->local_address))) {
         ast_log(LOG_ERROR, "Unable to bind %s to %s:%d: %s\n",
         desc->name,
            ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
            strerror(errno));
         goto error;
      }
   }

   if (!(tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor)))
      goto error;

   ast_mutex_init(&tcptls_session->lock);
   tcptls_session->client = 1;
   tcptls_session->fd = desc->accept_fd;
   tcptls_session->parent = desc;
   tcptls_session->parent->worker_fn = NULL;
   memcpy(&tcptls_session->remote_address, &desc->remote_address, sizeof(tcptls_session->remote_address));

   return tcptls_session;

error:
   close(desc->accept_fd);
   desc->accept_fd = -1;
   if (tcptls_session)
      ao2_ref(tcptls_session, -1);
   return NULL;
}

struct ast_tcptls_session_instance* ast_tcptls_client_start

(

struct ast_tcptls_session_instance *

tcptls_session

)

[read]

attempts to connect and start tcptls session, on error the tcptls_session's ref count is decremented, fd and file are closed, and NULL is returned.

Definition at line 339 of file tcptls.c.

References __ssl_setup(), ast_tcptls_session_args::accept_fd, ao2_ref, ast_inet_ntoa(), ast_log(), desc, ast_tls_config::enabled, errno, handle_tcptls_connection(), LOG_ERROR, ast_tcptls_session_args::name, ast_tcptls_session_instance::parent, ast_tcptls_session_args::remote_address, and ast_tcptls_session_args::tls_cfg.

Referenced by _sip_tcp_helper_thread(), and app_exec().

{
   struct ast_tcptls_session_args *desc;
   int flags;

   if (!(desc = tcptls_session->parent)) {
      goto client_start_error;
   }

   if (connect(desc->accept_fd, (const struct sockaddr *) &desc->remote_address, sizeof(desc->remote_address))) {
      ast_log(LOG_ERROR, "Unable to connect %s to %s:%d: %s\n",
         desc->name,
         ast_inet_ntoa(desc->remote_address.sin_addr), ntohs(desc->remote_address.sin_port),
         strerror(errno));
      goto client_start_error;
   }

   flags = fcntl(desc->accept_fd, F_GETFL);
   fcntl(desc->accept_fd, F_SETFL, flags & ~O_NONBLOCK);

   if (desc->tls_cfg) {
      desc->tls_cfg->enabled = 1;
      __ssl_setup(desc->tls_cfg, 1);
   }

   return handle_tcptls_connection(tcptls_session);

client_start_error:
   close(desc->accept_fd);
   desc->accept_fd = -1;
   if (tcptls_session) {
      ao2_ref(tcptls_session, -1);
   }
   return NULL;

}

HOOK_T ast_tcptls_server_read	(	struct ast_tcptls_session_instance *	tcptls_session,
		void *	buf,
		size_t	count
	)

replacement read/write functions for SSL support. We use wrappers rather than SSL_read/SSL_write directly so we can put in some debugging.

Definition at line 85 of file tcptls.c.

References ast_log(), errno, ast_tcptls_session_instance::fd, LOG_ERROR, and ast_tcptls_session_instance::ssl.

{
   if (tcptls_session->fd == -1) {
      ast_log(LOG_ERROR, "server_read called with an fd of -1\n");
      errno = EIO;
      return -1;
   }

#ifdef DO_SSL
   if (tcptls_session->ssl)
      return ssl_read(tcptls_session->ssl, buf, count);
#endif
   return read(tcptls_session->fd, buf, count);
}

void* ast_tcptls_server_root

(

void *

data

)

Definition at line 233 of file tcptls.c.

References ast_tcptls_session_args::accept_fd, ao2_alloc, ao2_ref, ast_log(), ast_mutex_init(), ast_pthread_create_detached_background, ast_wait_for_input(), ast_tcptls_session_instance::client, desc, errno, ast_tcptls_session_instance::fd, handle_tcptls_connection(), ast_tcptls_session_instance::lock, LOG_WARNING, ast_tcptls_session_instance::parent, ast_tcptls_session_args::periodic_fn, ast_tcptls_session_args::poll_timeout, ast_tcptls_session_instance::remote_address, and session_instance_destructor().

{
   struct ast_tcptls_session_args *desc = data;
   int fd;
   struct sockaddr_in sin;
   socklen_t sinlen;
   struct ast_tcptls_session_instance *tcptls_session;
   pthread_t launched;
   
   for (;;) {
      int i, flags;

      if (desc->periodic_fn)
         desc->periodic_fn(desc);
      i = ast_wait_for_input(desc->accept_fd, desc->poll_timeout);
      if (i <= 0)
         continue;
      sinlen = sizeof(sin);
      fd = accept(desc->accept_fd, (struct sockaddr *) &sin, &sinlen);
      if (fd < 0) {
         if ((errno != EAGAIN) && (errno != EINTR))
            ast_log(LOG_WARNING, "Accept failed: %s\n", strerror(errno));
         continue;
      }
      tcptls_session = ao2_alloc(sizeof(*tcptls_session), session_instance_destructor);
      if (!tcptls_session) {
         ast_log(LOG_WARNING, "No memory for new session: %s\n", strerror(errno));
         close(fd);
         continue;
      }

      ast_mutex_init(&tcptls_session->lock);

      flags = fcntl(fd, F_GETFL);
      fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
      tcptls_session->fd = fd;
      tcptls_session->parent = desc;
      memcpy(&tcptls_session->remote_address, &sin, sizeof(tcptls_session->remote_address));

      tcptls_session->client = 0;
         
      /* This thread is now the only place that controls the single ref to tcptls_session */
      if (ast_pthread_create_detached_background(&launched, NULL, handle_tcptls_connection, tcptls_session)) {
         ast_log(LOG_WARNING, "Unable to launch helper thread: %s\n", strerror(errno));
         close(tcptls_session->fd);
         ao2_ref(tcptls_session, -1);
      }
   }
   return NULL;
}

void ast_tcptls_server_start

(

struct ast_tcptls_session_args *

desc

)

This is a generic (re)start routine for a TCP server, which does the socket/bind/listen and starts a thread for handling accept().

Version:

1.6.1 changed desc parameter to be of ast_tcptls_session_args type

Definition at line 432 of file tcptls.c.

References ast_tcptls_session_args::accept_fd, ast_tcptls_session_args::accept_fn, ast_debug, ast_inet_ntoa(), ast_log(), ast_pthread_create_background, AST_PTHREADT_NULL, errno, ast_tcptls_session_args::local_address, LOG_ERROR, ast_tcptls_session_args::master, ast_tcptls_session_args::name, and ast_tcptls_session_args::old_address.

Referenced by __ast_http_load(), __init_manager(), and reload_config().

{
   int flags;
   int x = 1;
   
   /* Do nothing if nothing has changed */
   if (!memcmp(&desc->old_address, &desc->local_address, sizeof(desc->old_address))) {
      ast_debug(1, "Nothing changed in %s\n", desc->name);
      return;
   }
   
   desc->old_address = desc->local_address;
   
   /* Shutdown a running server if there is one */
   if (desc->master != AST_PTHREADT_NULL) {
      pthread_cancel(desc->master);
      pthread_kill(desc->master, SIGURG);
      pthread_join(desc->master, NULL);
   }
   
   if (desc->accept_fd != -1)
      close(desc->accept_fd);

   /* If there's no new server, stop here */
   if (desc->local_address.sin_family == 0) {
      return;
   }

   desc->accept_fd = socket(AF_INET, SOCK_STREAM, 0);
   if (desc->accept_fd < 0) {
      ast_log(LOG_ERROR, "Unable to allocate socket for %s: %s\n",
         desc->name, strerror(errno));
      return;
   }
   
   setsockopt(desc->accept_fd, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
   if (bind(desc->accept_fd, (struct sockaddr *) &desc->local_address, sizeof(desc->local_address))) {
      ast_log(LOG_ERROR, "Unable to bind %s to %s:%d: %s\n",
         desc->name,
         ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
         strerror(errno));
      goto error;
   }
   if (listen(desc->accept_fd, 10)) {
      ast_log(LOG_ERROR, "Unable to listen for %s!\n", desc->name);
      goto error;
   }
   flags = fcntl(desc->accept_fd, F_GETFL);
   fcntl(desc->accept_fd, F_SETFL, flags | O_NONBLOCK);
   if (ast_pthread_create_background(&desc->master, NULL, desc->accept_fn, desc)) {
      ast_log(LOG_ERROR, "Unable to launch thread for %s on %s:%d: %s\n",
         desc->name,
         ast_inet_ntoa(desc->local_address.sin_addr), ntohs(desc->local_address.sin_port),
         strerror(errno));
      goto error;
   }
   return;

error:
   close(desc->accept_fd);
   desc->accept_fd = -1;
}

void ast_tcptls_server_stop

(

struct ast_tcptls_session_args *

desc

)

Shutdown a running server if there is one.

Version:

1.6.1 changed desc parameter to be of ast_tcptls_session_args type

Definition at line 495 of file tcptls.c.

References ast_tcptls_session_args::accept_fd, AST_PTHREADT_NULL, and ast_tcptls_session_args::master.

Referenced by unload_module().

{
   if (desc->master != AST_PTHREADT_NULL) {
      pthread_cancel(desc->master);
      pthread_kill(desc->master, SIGURG);
      pthread_join(desc->master, NULL);
   }
   if (desc->accept_fd != -1)
      close(desc->accept_fd);
   desc->accept_fd = -1;
}

HOOK_T ast_tcptls_server_write	(	struct ast_tcptls_session_instance *	tcptls_session,
		void *	buf,
		size_t	count
	)

Definition at line 100 of file tcptls.c.

References ast_log(), errno, ast_tcptls_session_instance::fd, LOG_ERROR, and ast_tcptls_session_instance::ssl.

Referenced by _sip_tcp_helper_thread().

{
   if (tcptls_session->fd == -1) {
      ast_log(LOG_ERROR, "server_write called with an fd of -1\n");
      errno = EIO;
      return -1;
   }

#ifdef DO_SSL
   if (tcptls_session->ssl)
      return ssl_write(tcptls_session->ssl, buf, count);
#endif
   return write(tcptls_session->fd, buf, count);
}

static void* handle_tcptls_connection

(

void *

data

)

[static]

creates a FILE * from the fd passed by the accept thread. This operation is potentially expensive (certificate verification), so we do it in the child thread context.

Note:

must decrement ref count before returning NULL on error

Definition at line 128 of file tcptls.c.

References ao2_ref, ast_debug, ast_log(), AST_SSL_DONT_VERIFY_SERVER, AST_SSL_IGNORE_COMMON_NAME, AST_SSL_VERIFY_CLIENT, ast_test_flag, ast_verb, ast_tcptls_session_instance::client, ast_tcptls_session_instance::f, ast_tcptls_session_instance::fd, ast_tls_config::flags, ast_tcptls_session_args::hostname, LOG_ERROR, LOG_WARNING, name, ast_tcptls_session_instance::parent, ast_tcptls_session_instance::ssl, ast_tls_config::ssl_ctx, str, ast_tcptls_session_args::tls_cfg, and ast_tcptls_session_args::worker_fn.

Referenced by ast_tcptls_client_start(), and ast_tcptls_server_root().

{
   struct ast_tcptls_session_instance *tcptls_session = data;
#ifdef DO_SSL
   int (*ssl_setup)(SSL *) = (tcptls_session->client) ? SSL_connect : SSL_accept;
   int ret;
   char err[256];
#endif

   /*
   * open a FILE * as appropriate.
   */
   if (!tcptls_session->parent->tls_cfg) {
      tcptls_session->f = fdopen(tcptls_session->fd, "w+");
      setvbuf(tcptls_session->f, NULL, _IONBF, 0);
   }
#ifdef DO_SSL
   else if ( (tcptls_session->ssl = SSL_new(tcptls_session->parent->tls_cfg->ssl_ctx)) ) {
      SSL_set_fd(tcptls_session->ssl, tcptls_session->fd);
      if ((ret = ssl_setup(tcptls_session->ssl)) <= 0) {
         ast_verb(2, "Problem setting up ssl connection: %s\n", ERR_error_string(ERR_get_error(), err));
      } else {
#if defined(HAVE_FUNOPEN)  /* the BSD interface */
         tcptls_session->f = funopen(tcptls_session->ssl, ssl_read, ssl_write, NULL, ssl_close);

#elif defined(HAVE_FOPENCOOKIE)  /* the glibc/linux interface */
         static const cookie_io_functions_t cookie_funcs = {
            ssl_read, ssl_write, NULL, ssl_close
         };
         tcptls_session->f = fopencookie(tcptls_session->ssl, "w+", cookie_funcs);
#else
         /* could add other methods here */
         ast_debug(2, "no tcptls_session->f methods attempted!");
#endif
         if ((tcptls_session->client && !ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_DONT_VERIFY_SERVER))
            || (!tcptls_session->client && ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_VERIFY_CLIENT))) {
            X509 *peer;
            long res;
            peer = SSL_get_peer_certificate(tcptls_session->ssl);
            if (!peer)
               ast_log(LOG_WARNING, "No peer SSL certificate\n");
            res = SSL_get_verify_result(tcptls_session->ssl);
            if (res != X509_V_OK)
               ast_log(LOG_ERROR, "Certificate did not verify: %s\n", X509_verify_cert_error_string(res));
            if (!ast_test_flag(&tcptls_session->parent->tls_cfg->flags, AST_SSL_IGNORE_COMMON_NAME)) {
               ASN1_STRING *str;
               unsigned char *str2;
               X509_NAME *name = X509_get_subject_name(peer);
               int pos = -1;
               int found = 0;
            
               for (;;) {
                  /* Walk the certificate to check all available "Common Name" */
                  /* XXX Probably should do a gethostbyname on the hostname and compare that as well */
                  pos = X509_NAME_get_index_by_NID(name, NID_commonName, pos);
                  if (pos < 0)
                     break;
                  str = X509_NAME_ENTRY_get_data(X509_NAME_get_entry(name, pos));
                  ASN1_STRING_to_UTF8(&str2, str);
                  if (str2) {
                     if (!strcasecmp(tcptls_session->parent->hostname, (char *) str2))
                        found = 1;
                     ast_debug(3, "SSL Common Name compare s1='%s' s2='%s'\n", tcptls_session->parent->hostname, str2);
                     OPENSSL_free(str2);
                  }
                  if (found)
                     break;
               }
               if (!found) {
                  ast_log(LOG_ERROR, "Certificate common name did not match (%s)\n", tcptls_session->parent->hostname);
                  if (peer)
                     X509_free(peer);
                  close(tcptls_session->fd);
                  fclose(tcptls_session->f);
                  ao2_ref(tcptls_session, -1);
                  return NULL;
               }
            }
            if (peer)
               X509_free(peer);
         }
      }
      if (!tcptls_session->f) /* no success opening descriptor stacking */
         SSL_free(tcptls_session->ssl);
   }
#endif /* DO_SSL */

   if (!tcptls_session->f) {
      close(tcptls_session->fd);
      ast_log(LOG_WARNING, "FILE * open failed!\n");
#ifndef DO_SSL
      if (tcptls_session->parent->tls_cfg) {
         ast_log(LOG_WARNING, "Attempted a TLS connection without OpenSSL support.  This will not work!\n");
      }
#endif
      ao2_ref(tcptls_session, -1);
      return NULL;
   }

   if (tcptls_session && tcptls_session->parent->worker_fn)
      return tcptls_session->parent->worker_fn(tcptls_session);
   else
      return tcptls_session;
}

static void session_instance_destructor

(

void *

obj

)

[static]

Definition at line 115 of file tcptls.c.

References ast_mutex_destroy(), and ast_tcptls_session_instance::lock.

Referenced by ast_tcptls_client_create(), and ast_tcptls_server_root().

{
   struct ast_tcptls_session_instance *i = obj;
   ast_mutex_destroy(&i->lock);
}