Re: [Qemu-devel] [PATCH] Modify net/socket.c to use socket_* functions from include/qemu/sockets.h

[Paolo Bonzini]

On 31/05/2016 11:27, Ashijeet Acharya wrote:
> Changed the listen(),connect(),parse_host_port() in net/socket.c with the 
> socket_*()functions in include/qemu/sockets.h.
> 
> Signed-off-by: Ashijeet Acharya <address@hidden>
> ---
>  net/socket.c | 38 +++++++++++++++++++-------------------
>  1 file changed, 19 insertions(+), 19 deletions(-)
> 
> diff --git a/net/socket.c b/net/socket.c
> index 9fa2cd8..b6e2f3e 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -522,10 +522,12 @@ static int net_socket_listen_init(NetClientState *peer,
>  {
>      NetClientState *nc;
>      NetSocketState *s;
> -    struct sockaddr_in saddr;
> +    SocketAddress *saddr;
>      int fd, ret;
> +    Error *local_error = NULL;
> 
> -    if (parse_host_port(&saddr, host_str) < 0)
> +    if (socket_parse(host_str, &local_error) < 0)

This leaks the return address.

The result of socket_parse should be stored in saddr.

Also, the right comparison is "!= NULL", not "< 0".

Finally, you're not printing the error (with error_report_err).

>          return -1;
> 
>      fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
> @@ -536,14 +538,9 @@ static int net_socket_listen_init(NetClientState *peer,
>      qemu_set_nonblock(fd);
>  
>      socket_set_fast_reuse(fd);
> +    saddr = socket_local_address(fd, &local_error);

This is incorrect too.  You're adding a call to getsockname that wasn't
in the original code.  You're also ignoring possible failures from
socket_local_address.

> -    ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
> -    if (ret < 0) {
> -        perror("bind");
> -        closesocket(fd);
> -        return -1;
> -    }
> -    ret = listen(fd, 0);
> +    ret = socket_listen(saddr, &local_error);
>      if (ret < 0) {
>          perror("listen");

You should use error_report_err instead of perror, since that's how
socket_listen returns errors.  You are also leaking saddr.

>          closesocket(fd);
> @@ -557,6 +554,7 @@ static int net_socket_listen_init(NetClientState *peer,
>      s->nc.link_down = true;
>  
>      qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
> +    g_free(saddr);

Use qapi_free_SocketAddress instead of g_free, because SocketAddress
includes pointers to other data structures that have to be freed.

>      return 0;
>  }
>  
> @@ -567,9 +565,11 @@ static int net_socket_connect_init(NetClientState *peer,
>  {
>      NetSocketState *s;
>      int fd, connected, ret;
> -    struct sockaddr_in saddr;
> +    SocketAddress *saddr;
> +    Error *local_error = NULL;
>  
> -    if (parse_host_port(&saddr, host_str) < 0)
> +    if (socket_parse(host_str, &local_error) < 0)

Same as above.

>          return -1;
>  
>      fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
> @@ -578,10 +578,10 @@ static int net_socket_connect_init(NetClientState *peer,
>          return -1;
>      }
>      qemu_set_nonblock(fd);
> -
> +    saddr = socket_local_address(fd, &local_error);

Same as above.  You probably haven't tested this patch well enough,
because otherwise you would have noticed the problem here.

>      connected = 0;
>      for(;;) {
> -        ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
> +        ret = socket_connect(saddr, &local_error, NULL, NULL);
>          if (ret < 0) {
>              if (errno == EINTR || errno == EWOULDBLOCK) {
>                  /* continue */
> @@ -602,9 +602,7 @@ static int net_socket_connect_init(NetClientState *peer,
>      s = net_socket_fd_init(peer, model, name, fd, connected);
>      if (!s)
>          return -1;
> -    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
> -             "socket: connect to %s:%d",
> -             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));

Here you should have created a new function socket_address_to_string in
util/qemu-sockets.c.  The function should return a new string
corresponding to the address.  The address can be IPv4/IPv6 (then
printing is done via inet_ntop), a Unix socket or a file descriptor; you
have to handle all three cases.

The return value of the function can be used together with snprintf to
form s->nc.info_str.

> +    g_free(saddr);
>      return 0;
>  }
>  
> @@ -618,8 +616,9 @@ static int net_socket_mcast_init(NetClientState *peer,
>      int fd;
>      struct sockaddr_in saddr;
>      struct in_addr localaddr, *param_localaddr;
> +    Error *local_error = NULL;
>  
> -    if (parse_host_port(&saddr, host_str) < 0)
> +    if (socket_parse(host_str, &local_error) < 0)
>          return -1;

Same problem as above.  In addition, saddr is being passed uninitialized
to net_socket_mcast_create.

>      if (localaddr_str != NULL) {
> @@ -656,12 +655,13 @@ static int net_socket_udp_init(NetClientState *peer,
>      NetSocketState *s;
>      int fd, ret;
>      struct sockaddr_in laddr, raddr;
> +    Error *local_error = NULL;
>  
> -    if (parse_host_port(&laddr, lhost) < 0) {
> +    if (socket_parse(lhost, &local_error) < 0) {
>          return -1;
>      }
>  
> -    if (parse_host_port(&raddr, rhost) < 0) {
> +    if (socket_parse(rhost, &local_error) < 0) {
>          return -1;
>      }

Same problem as above.  In addition, laddr and raddr are being used
uninitialized.  At least in the case of raddr, the compiler should have
noticed this and issued a warning.

Thanks,

Paolo