Handle data coming in over the channel as VPPackets: Process control messages and forward data from remote client/server connections to the appropriate server/client FD on our end.
Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com> --- virtproxy.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 83 insertions(+), 0 deletions(-) diff --git a/virtproxy.c b/virtproxy.c index 20532c2..c9c3022 100644 --- a/virtproxy.c +++ b/virtproxy.c @@ -33,6 +33,7 @@ #define VP_SERVICE_ID_LEN 32 /* max length of service id string */ #define VP_PKT_DATA_LEN 1024 /* max proxied bytes per VPPacket */ #define VP_CONN_DATA_LEN 1024 /* max bytes conns can send at a time */ +#define VP_CHAN_DATA_LEN 4096 /* max bytes channel can send at a time */ #define VP_MAGIC 0x1F374059 /* listening fd, one for each service we're forwarding to remote end */ @@ -150,6 +151,8 @@ static QemuOptsList vp_socket_opts = { }, }; +static void vp_channel_read(void *opaque); + /* get VPConn by fd, "client" denotes whether to look for client or server */ static VPConn *get_conn(const VPDriver *drv, int fd, bool client) { @@ -230,3 +233,83 @@ static void vp_channel_accept(void *opaque) /* dont accept anymore connections until channel_fd is closed */ vp_set_fd_handler(drv->listen_fd, NULL, NULL, NULL); } + +/* read handler for communication channel + * + * de-multiplexes data coming in over the channel. for control messages + * we process them here, for data destined for a service or client we + * send it to the appropriate FD. + */ +static void vp_channel_read(void *opaque) +{ + VPDriver *drv = opaque; + VPPacket pkt; + int count, ret, buf_offset; + char buf[VP_CHAN_DATA_LEN]; + char *pkt_ptr, *buf_ptr; + + TRACE("called with opaque: %p", drv); + + count = read(drv->channel_fd, buf, sizeof(buf)); + + if (count == -1) { + LOG("read() failed: %s", strerror(errno)); + return; + } else if (count == 0) { + /* TODO: channel closed, this probably shouldn't happen for guest-side + * serial/virtio-serial connections, but need to confirm and consider + * what should happen in this case. as it stands this virtproxy instance + * is basically defunct at this point, same goes for "client" instances + * of virtproxy where the remote end has hung-up. + */ + LOG("channel connection closed"); + vp_set_fd_handler(drv->channel_fd, NULL, NULL, drv); + drv->channel_fd = -1; + if (drv->listen_fd) { + vp_set_fd_handler(drv->listen_fd, vp_channel_accept, NULL, drv); + } + /* TODO: should close/remove/delete all existing VPConns here */ + } + + if (drv->buflen + count >= sizeof(VPPacket)) { + TRACE("initial packet, drv->buflen: %d", drv->buflen); + pkt_ptr = (char *)&pkt; + memcpy(pkt_ptr, drv->buf, drv->buflen); + pkt_ptr += drv->buflen; + memcpy(pkt_ptr, buf, sizeof(VPPacket) - drv->buflen); + /* handle first packet */ + ret = vp_handle_packet(drv, &pkt); + if (ret != 0) { + LOG("error handling packet"); + } + /* handle the rest of the buffer */ + buf_offset = sizeof(VPPacket) - drv->buflen; + drv->buflen = 0; + buf_ptr = buf + buf_offset; + count -= buf_offset; + while (count > 0) { + if (count >= sizeof(VPPacket)) { + /* handle full packet */ + TRACE("additional packet, drv->buflen: %d", drv->buflen); + memcpy((void *)&pkt, buf_ptr, sizeof(VPPacket)); + ret = vp_handle_packet(drv, &pkt); + if (ret != 0) { + LOG("error handling packet"); + } + count -= sizeof(VPPacket); + buf_ptr += sizeof(VPPacket); + } else { + /* buffer the remainder */ + TRACE("buffering packet"); + memcpy(drv->buf, buf_ptr, count); + drv->buflen = count; + break; + } + } + } else { + /* haven't got a full VPPacket yet, buffer for later */ + buf_ptr = drv->buf + drv->buflen; + memcpy(buf_ptr, buf, count); + drv->buflen += count; + } +} -- 1.7.0.4