Commit 9c94236e authored by Marc Hoersken's avatar Marc Hoersken Committed by Daniel Stenberg
Browse files

connect.c/ftp.c: Fixed dereferencing pointer breakin strict-aliasing 

Fixed warning: dereferencing pointer does break strict-aliasing rules
by using a union instead of separate pointer variables.
Internal union sockaddr_u could probably be moved to generic header.
Thanks to Paul Howarth for the hint about using unions for this.

Important for winbuild: Separate declaration of sockaddr_u pointer.
The pointer variable *sock cannot be declared and initialized right
after the union declaration. Therefore it has to be a separate statement.
parent 3f9ab7cf

lib/connect.c

+21 −17
Original line number Diff line number Diff line
@@ -253,12 +253,16 @@ static CURLcode bindlocal(struct connectdata *conn, 
  struct SessionHandle *data = conn->data;



  struct Curl_sockaddr_storage sa;

  struct sockaddr *sock = (struct sockaddr *)&sa;  /* bind to this address */

  curl_socklen_t sizeof_sa = 0; /* size of the data sock points to */

  struct sockaddr_in *si4 = (struct sockaddr_in *)&sa;



  union sockaddr_u {

    struct sockaddr sa;

    struct sockaddr_in sa4;

#ifdef ENABLE_IPV6

  struct sockaddr_in6 *si6 = (struct sockaddr_in6 *)&sa;

    struct sockaddr_in6 sa6;

#endif

  };

  union sockaddr_u *sock = (union sockaddr_u *)&sa; /* bind to this address */



  struct Curl_dns_entry *h=NULL;

  unsigned short port = data->set.localport; /* use this port number, 0 for
@@ -373,18 +377,18 @@ static CURLcode bindlocal(struct connectdata *conn, 
#ifdef ENABLE_IPV6

      /* ipv6 address */

      if((af == AF_INET6) &&

         (Curl_inet_pton(AF_INET6, myhost, &si6->sin6_addr) > 0)) {

        si6->sin6_family = AF_INET6;

        si6->sin6_port = htons(port);

         (Curl_inet_pton(AF_INET6, myhost, &sock->sa6.sin6_addr) > 0)) {

        sock->sa6.sin6_family = AF_INET6;

        sock->sa6.sin6_port = htons(port);

        sizeof_sa = sizeof(struct sockaddr_in6);

      }

      else

#endif

      /* ipv4 address */

      if((af == AF_INET) &&

         (Curl_inet_pton(AF_INET, myhost, &si4->sin_addr) > 0)) {

        si4->sin_family = AF_INET;

        si4->sin_port = htons(port);

         (Curl_inet_pton(AF_INET, myhost, &sock->sa4.sin_addr) > 0)) {

        sock->sa4.sin_family = AF_INET;

        sock->sa4.sin_port = htons(port);

        sizeof_sa = sizeof(struct sockaddr_in);

      }

    }
@@ -398,21 +402,21 @@ static CURLcode bindlocal(struct connectdata *conn, 
    /* no device was given, prepare sa to match af's needs */

#ifdef ENABLE_IPV6

    if(af == AF_INET6) {

      si6->sin6_family = AF_INET6;

      si6->sin6_port = htons(port);

      sock->sa6.sin6_family = AF_INET6;

      sock->sa6.sin6_port = htons(port);

      sizeof_sa = sizeof(struct sockaddr_in6);

    }

    else

#endif

    if(af == AF_INET) {

      si4->sin_family = AF_INET;

      si4->sin_port = htons(port);

      sock->sa4.sin_family = AF_INET;

      sock->sa4.sin_port = htons(port);

      sizeof_sa = sizeof(struct sockaddr_in);

    }

  }



  for(;;) {

    if(bind(sockfd, sock, sizeof_sa) >= 0) {

    if(bind(sockfd, &sock->sa, sizeof_sa) >= 0) {

      /* we succeeded to bind */

      struct Curl_sockaddr_storage add;

      curl_socklen_t size = sizeof(add);
@@ -432,11 +436,11 @@ static CURLcode bindlocal(struct connectdata *conn, 
      infof(data, "Bind to local port %hu failed, trying next\n", port);

      port++; /* try next port */

      /* We re-use/clobber the port variable here below */

      if(sock->sa_family == AF_INET)

        si4->sin_port = ntohs(port);

      if(sock->sa.sa_family == AF_INET)

        sock->sa4.sin_port = ntohs(port);

#ifdef ENABLE_IPV6

      else

        si6->sin6_port = ntohs(port);

        sock->sa6.sin6_port = ntohs(port);

#endif

    }

    else

lib/ftp.c

+28 −22
Original line number Diff line number Diff line
@@ -955,14 +955,18 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
  char myhost[256] = "";



  struct Curl_sockaddr_storage ss;

  union sockaddr_u {

    struct sockaddr sa;

    struct sockaddr_in sa4;

#ifdef ENABLE_IPV6

    struct sockaddr_in6 sa6;

#endif

  };

  union sockaddr_u *sock = (union sockaddr_u *)&ss;



  Curl_addrinfo *res, *ai;

  curl_socklen_t sslen;

  char hbuf[NI_MAXHOST];

  struct sockaddr *sa=(struct sockaddr *)&ss;

  struct sockaddr_in * const sa4 = (void *)sa;

#ifdef ENABLE_IPV6

  struct sockaddr_in6 * const sa6 = (void *)sa;

#endif

  char tmp[1024];

  static const char mode[][5] = { "EPRT", "PORT" };

  int rc;
@@ -1017,7 +1021,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
    else if((ip_end = strchr(string_ftpport, ':')) != NULL) {

        /* either ipv6 or (ipv4|domain|interface):port(-range) */

#ifdef ENABLE_IPV6

      if(Curl_inet_pton(AF_INET6, string_ftpport, sa6) == 1) {

      if(Curl_inet_pton(AF_INET6, string_ftpport, &sock->sa6) == 1) {

        /* ipv6 */

        port_min = port_max = 0;

        strcpy(addr, string_ftpport);
@@ -1073,20 +1077,22 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
       the IP from the control connection */



    sslen = sizeof(ss);

    if(getsockname(conn->sock[FIRSTSOCKET], sa, &sslen)) {

    if(getsockname(conn->sock[FIRSTSOCKET], &sock->sa, &sslen)) {

      failf(data, "getsockname() failed: %s",

          Curl_strerror(conn, SOCKERRNO) );

      Curl_safefree(addr);

      return CURLE_FTP_PORT_FAILED;

    }

    switch(sa->sa_family) {

    switch(sock->sa.sa_family) {

#ifdef ENABLE_IPV6

    case AF_INET6:

      Curl_inet_ntop(sa->sa_family, &sa6->sin6_addr, hbuf, sizeof(hbuf));

      Curl_inet_ntop(sock->sa.sa_family, &sock->sa6.sin6_addr, hbuf,

                     sizeof(hbuf));

      break;

#endif

    default:

      Curl_inet_ntop(sa->sa_family, &sa4->sin_addr, hbuf, sizeof(hbuf));

      Curl_inet_ntop(sock->sa.sa_family, &sock->sa4.sin_addr, hbuf,

                     sizeof(hbuf));

      break;

    }

    host = hbuf; /* use this host name */
@@ -1134,18 +1140,18 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 


  /* step 3, bind to a suitable local address */



  memcpy(sa, ai->ai_addr, ai->ai_addrlen);

  memcpy(&sock->sa, ai->ai_addr, ai->ai_addrlen);

  sslen = ai->ai_addrlen;



  for(port = port_min; port <= port_max;) {

    if(sa->sa_family == AF_INET)

      sa4->sin_port = htons(port);

    if(sock->sa.sa_family == AF_INET)

      sock->sa4.sin_port = htons(port);

#ifdef ENABLE_IPV6

    else

      sa6->sin6_port = htons(port);

      sock->sa6.sin6_port = htons(port);

#endif

    /* Try binding the given address. */

    if(bind(portsock, sa, sslen) ) {

    if(bind(portsock, &sock->sa, sslen) ) {

      /* It failed. */

      error = SOCKERRNO;

      if(possibly_non_local && (error == EADDRNOTAVAIL)) {
@@ -1157,7 +1163,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
              Curl_strerror(conn, error) );



        sslen = sizeof(ss);

        if(getsockname(conn->sock[FIRSTSOCKET], sa, &sslen)) {

        if(getsockname(conn->sock[FIRSTSOCKET], &sock->sa, &sslen)) {

          failf(data, "getsockname() failed: %s",

                Curl_strerror(conn, SOCKERRNO) );

          Curl_closesocket(conn, portsock);
@@ -1190,7 +1196,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
  /* get the name again after the bind() so that we can extract the

     port number it uses now */

  sslen = sizeof(ss);

  if(getsockname(portsock, (struct sockaddr *)sa, &sslen)) {

  if(getsockname(portsock, (struct sockaddr *)&sock->sa, &sslen)) {

    failf(data, "getsockname() failed: %s",

          Curl_strerror(conn, SOCKERRNO) );

    Curl_closesocket(conn, portsock);
@@ -1224,17 +1230,17 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
      /* if disabled, goto next */

      continue;



    if((PORT == fcmd) && sa->sa_family != AF_INET)

    if((PORT == fcmd) && sock->sa.sa_family != AF_INET)

      /* PORT is ipv4 only */

      continue;



    switch (sa->sa_family) {

    switch (sock->sa.sa_family) {

    case AF_INET:

      port = ntohs(sa4->sin_port);

      port = ntohs(sock->sa4.sin_port);

      break;

#ifdef ENABLE_IPV6

    case AF_INET6:

      port = ntohs(sa6->sin6_port);

      port = ntohs(sock->sa6.sin6_port);

      break;

#endif

    default:
@@ -1251,7 +1257,7 @@ static CURLcode ftp_state_use_port(struct connectdata *conn, 
       */



      result = Curl_pp_sendf(&ftpc->pp, "%s |%d|%s|%hu|", mode[fcmd],

                             sa->sa_family == AF_INET?1:2,

                             sock->sa.sa_family == AF_INET?1:2,

                             myhost, port);

      if(result) {

        failf(data, "Failure sending EPRT command: %s",