On 06/24/2015 11:56 PM, Thomas Huth wrote:
> Adding a proper receive_iov function to the net dump module. This
> will make it easier to support the dump feature for the -netdev
> option in later patches.
> Also make the receive functions available to the other parts of the
> source code so we can later use them for dumping from net.c, too.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> net/clients.h | 3 +++
> net/dump.c | 48 ++++++++++++++++++++++++++++++++++++++++--------
> 2 files changed, 43 insertions(+), 8 deletions(-)
>
> diff --git a/net/clients.h b/net/clients.h
> index d47530e..5092f3d 100644
> --- a/net/clients.h
> +++ b/net/clients.h
> @@ -29,6 +29,9 @@
>
> int net_init_dump(const NetClientOptions *opts, const char *name,
> NetClientState *peer, Error **errp);
> +ssize_t net_dump_receive(NetClientState *nc, const uint8_t *buf, size_t
> size);
> +ssize_t net_dump_receive_iov(NetClientState *nc, const struct iovec *iov,
> + int cnt);
>
> #ifdef CONFIG_SLIRP
> int net_init_slirp(const NetClientOptions *opts, const char *name,
> diff --git a/net/dump.c b/net/dump.c
> index 02c8064..383718a 100644
> --- a/net/dump.c
> +++ b/net/dump.c
> @@ -57,27 +57,49 @@ struct pcap_sf_pkthdr {
> uint32_t len;
> };
>
> -static ssize_t dump_receive(NetClientState *nc, const uint8_t *buf, size_t
> size)
> +ssize_t net_dump_receive_iov(NetClientState *nc, const struct iovec *iov,
> + int cnt)
> {
> DumpState *s = DO_UPCAST(DumpState, nc, nc);
> struct pcap_sf_pkthdr hdr;
> int64_t ts;
> - int caplen;
> + int caplen, i;
> + size_t size = 0;
> + struct iovec dumpiov[cnt + 1];
>
> /* Early return in case of previous error. */
> if (s->fd < 0) {
> return size;
> }
>
> + dumpiov[0].iov_base = &hdr;
> + dumpiov[0].iov_len = sizeof(hdr);
> + caplen = s->pcap_caplen;
> +
> + /* Copy iov, limit maximum size to caplen, and count total input size */
> + for (i = 0; i < cnt; i++) {
> + dumpiov[i + 1].iov_base = iov[i].iov_base;
> + if (size + iov[i].iov_len <= caplen) {
> + dumpiov[i + 1].iov_len = iov[i].iov_len;
> + } else if (size < caplen) {
> + dumpiov[i + 1].iov_len = caplen - size;
> + } else {
> + dumpiov[i + 1].iov_len = 0;
> + }
> + size += iov[i].iov_len;
> + }
I believe we could use iov_copy() here.
> +
> ts = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 1000000,
> get_ticks_per_sec());
> - caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
> + if (size < caplen) {
> + caplen = size;
> + }
>
> hdr.ts.tv_sec = ts / 1000000 + s->start_ts;
> hdr.ts.tv_usec = ts % 1000000;
> hdr.caplen = caplen;
> hdr.len = size;
> - if (write(s->fd, &hdr, sizeof(hdr)) != sizeof(hdr) ||
> - write(s->fd, buf, caplen) != caplen) {
> +
> + if (writev(s->fd, dumpiov, cnt + 1) != sizeof(hdr) + caplen) {
> qemu_log("-net dump write error - stop dump\n");
> close(s->fd);
> s->fd = -1;
> @@ -86,7 +108,16 @@ static ssize_t dump_receive(NetClientState *nc, const
> uint8_t *buf, size_t size)
> return size;
> }
>
> -static void dump_cleanup(NetClientState *nc)
> +ssize_t net_dump_receive(NetClientState *nc, const uint8_t *buf, size_t size)
> +{
> + struct iovec iov = {
> + .iov_base = (void *)buf,
> + .iov_len = size
> + };
> + return net_dump_receive_iov(nc, &iov, 1);
> +}
> +
> +static void net_dump_cleanup(NetClientState *nc)
> {
> DumpState *s = DO_UPCAST(DumpState, nc, nc);
>
> @@ -96,8 +127,9 @@ static void dump_cleanup(NetClientState *nc)
> static NetClientInfo net_dump_info = {
> .type = NET_CLIENT_OPTIONS_KIND_DUMP,
> .size = sizeof(DumpState),
> - .receive = dump_receive,
> - .cleanup = dump_cleanup,
> + .receive = net_dump_receive,
> + .receive_iov = net_dump_receive_iov,
> + .cleanup = net_dump_cleanup,
> };
>
> static int net_dump_init(NetClientState *peer, const char *device,
