[ovs-dev] [optimize 07/13] socket-util: New function get_socket_rcvbuf().

[Ethan Jackson]

Looks good.

Ethan

On Tue, Sep 27, 2011 at 16:27, Ben Pfaff <blp at nicira.com> wrote:
> This will be used in an upcoming commit.
> ---
>  lib/socket-util.c |   60 ++++++++++++++++++++++++++++++++++++++---------------
>  lib/socket-util.h |    1 +
>  2 files changed, 44 insertions(+), 17 deletions(-)
>
> diff --git a/lib/socket-util.c b/lib/socket-util.c
> index 65b57ca..6e248c8 100644
> --- a/lib/socket-util.c
> +++ b/lib/socket-util.c
> @@ -59,6 +59,9 @@ VLOG_DEFINE_THIS_MODULE(socket_util);
>  #define O_DIRECTORY 0
>  #endif
>
> +static int getsockopt_int(int fd, int level, int option, const char *optname,
> +                          int *valuep);
> +
>  /* Sets 'fd' to non-blocking mode.  Returns 0 if successful, otherwise a
>  * positive errno value. */
>  int
> @@ -182,11 +185,9 @@ int
>  get_socket_error(int fd)
>  {
>     int error;
> -    socklen_t len = sizeof(error);
> -    if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
> -        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
> +
> +    if (getsockopt_int(fd, SOL_SOCKET, SO_ERROR, "SO_ERROR", &error)) {
>         error = errno;
> -        VLOG_ERR_RL(&rl, "getsockopt(SO_ERROR): %s", strerror(error));
>     }
>     return error;
>  }
> @@ -221,15 +222,13 @@ check_connection_completion(int fd)
>  int
>  drain_rcvbuf(int fd)
>  {
> -    socklen_t rcvbuf_len;
> -    size_t rcvbuf = 0;
> +    size_t rcvbuf;
>
> -    rcvbuf_len = sizeof rcvbuf;
> -    if (getsockopt(fd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &rcvbuf_len) < 0) {
> -        static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
> -        VLOG_ERR_RL(&rl, "getsockopt(SO_RCVBUF) failed: %s", strerror(errno));
> -        return errno;
> +    rcvbuf = get_socket_rcvbuf(fd);
> +    if (rcvbuf < 0) {
> +        return -rcvbuf;
>     }
> +
>     while (rcvbuf > 0) {
>         /* In Linux, specifying MSG_TRUNC in the flags argument causes the
>          * datagram length to be returned, even if that is longer than the
> @@ -250,6 +249,18 @@ drain_rcvbuf(int fd)
>     return 0;
>  }
>
> +/* Returns the size of socket 'sock''s receive buffer (SO_RCVBUF), or a
> + * negative errno value if an error occurs. */
> +int
> +get_socket_rcvbuf(int sock)
> +{
> +    int rcvbuf;
> +    int error;
> +
> +    error = getsockopt_int(sock, SOL_SOCKET, SO_RCVBUF, "SO_RCVBUF", &rcvbuf);
> +    return error ? -error : rcvbuf;
> +}
> +
>  /* Reads and discards up to 'n' datagrams from 'fd', stopping as soon as no
>  * more data can be immediately read.  ('fd' should therefore be in
>  * non-blocking mode.)*/
> @@ -846,13 +857,27 @@ xpipe(int fds[2])
>  }
>
>  static int
> -getsockopt_int(int fd, int level, int optname, int *valuep)
> +getsockopt_int(int fd, int level, int option, const char *optname, int *valuep)
>  {
> -    socklen_t len = sizeof *valuep;
> +    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 10);
> +    socklen_t len;
> +    int value;
> +    int error;
>
> -    return (getsockopt(fd, level, optname, valuep, &len) ? errno
> -            : len == sizeof *valuep ? 0
> -            : EINVAL);
> +    len = sizeof value;
> +    if (getsockopt(fd, level, option, &value, &len)) {
> +        error = errno;
> +        VLOG_ERR_RL(&rl, "getsockopt(%s): %s", optname, strerror(error));
> +    } else if (len != sizeof value) {
> +        error = EINVAL;
> +        VLOG_ERR_RL(&rl, "getsockopt(%s): value is %u bytes (expected %zu)",
> +                    optname, (unsigned int) len, sizeof value);
> +    } else {
> +        error = 0;
> +    }
> +
> +    *valuep = error ? 0 : value;
> +    return error;
>  }
>
>  static void
> @@ -890,7 +915,8 @@ describe_sockaddr(struct ds *string, int fd,
>  #define SO_PROTOCOL 38
>  #endif
>
> -            if (!getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, &protocol)) {
> +            if (!getsockopt_int(fd, SOL_SOCKET, SO_PROTOCOL, "SO_PROTOCOL",
> +                                &protocol)) {
>                 switch (protocol) {
>                 case NETLINK_ROUTE:
>                     ds_put_cstr(string, "NETLINK_ROUTE");
> diff --git a/lib/socket-util.h b/lib/socket-util.h
> index 1059139..422cea9 100644
> --- a/lib/socket-util.h
> +++ b/lib/socket-util.h
> @@ -33,6 +33,7 @@ int lookup_ipv6(const char *host_name, struct in6_addr *address);
>  int lookup_hostname(const char *host_name, struct in_addr *);
>
>  int get_socket_error(int sock);
> +int get_socket_rcvbuf(int sock);
>  int check_connection_completion(int fd);
>  int drain_rcvbuf(int fd);
>  void drain_fd(int fd, size_t n_packets);
> --
> 1.7.4.4
>
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