[Spice-devel] [spice-server 1/3] test_vdagent: Pass proper types to spice_server_add_interface

[Christophe Fergeau]

On Tue, Jan 31, 2017 at 07:45:44AM -0500, Frediano Ziglio wrote:
> Title should be test-vdagent (with dash).

Thanks, fixed.

> 
> > 
> > This is a revert of 93b4f4050^ and 93b4f4050.
> > For a SpiceCharDeviceInstance, the base interface must be a
> > SpiceCharDeviceInterface instance, not a SpiceBaseInterface instance, or
> > spice-server code will end up reading out of bounds.
> > 
> > vmc_state/vmc_write/vmc_read implementations also have to be provided.
> > ---
> >  server/tests/test-vdagent.c | 65
> >  ++++++++++++++++++++++++++++++++++++++++-----
> >  1 file changed, 59 insertions(+), 6 deletions(-)
> > 
> > diff --git a/server/tests/test-vdagent.c b/server/tests/test-vdagent.c
> > index 7f905ad..e06229e 100644
> > --- a/server/tests/test-vdagent.c
> > +++ b/server/tests/test-vdagent.c
> > @@ -45,11 +45,64 @@ static void pinger(SPICE_GNUC_UNUSED void *opaque)
> >      core->timer_start(ping_timer, ping_ms);
> >  }
> >  
> > -static SpiceBaseInterface base = {
> > -    .type          = SPICE_INTERFACE_CHAR_DEVICE,
> > -    .description   = "test spice virtual channel char device",
> > -    .major_version = SPICE_INTERFACE_CHAR_DEVICE_MAJOR,
> > -    .minor_version = SPICE_INTERFACE_CHAR_DEVICE_MINOR,
> > +static int vmc_write(SPICE_GNUC_UNUSED SpiceCharDeviceInstance *sin,
> > +                     SPICE_GNUC_UNUSED const uint8_t *buf,
> > +                     int len)
> > +{
> > +    return len;
> > +}
> > +
> > +static int vmc_read(SPICE_GNUC_UNUSED SpiceCharDeviceInstance *sin,
> > +                    uint8_t *buf,
> > +                    int len)
> > +{
> > +    static uint8_t c = 0;
> > +    static uint8_t message[2048];
> > +    static unsigned pos = 0;
> > +    static unsigned message_size;
> > +    int ret;
> > +
> > +    if (pos == 0) {
> > +        VDIChunkHeader *hdr = (VDIChunkHeader *)message;
> > +        VDAgentMessage *msg = (VDAgentMessage *)&hdr[1];
> > +        uint8_t *p = message;
> > +        int size = sizeof(message);
> > +        message_size = size;
> > +        /* fill in message */
> > +        hdr->port = VDP_SERVER_PORT;
> > +        hdr->size = message_size - sizeof(VDIChunkHeader);
> > +        msg->protocol = VD_AGENT_PROTOCOL;
> > +        msg->type = VD_AGENT_END_MESSAGE;
> > +        msg->opaque = 0;
> > +        msg->size = message_size - sizeof(VDIChunkHeader) -
> > sizeof(VDAgentMessage);
> > +        size -= sizeof(VDIChunkHeader) + sizeof(VDAgentMessage);
> > +        p += sizeof(VDIChunkHeader) + sizeof(VDAgentMessage);
> > +        for (; size; --size, ++p, ++c)
> > +            *p = c;
> > +    }
> > +    ret = MIN(message_size - pos, len);
> > +    memcpy(buf, &message[pos], ret);
> > +    pos += ret;
> > +    if (pos == message_size) {
> > +        pos = 0;
> > +    }
> > +    //printf("vmc_read %d (ret %d)\n", len, ret);
> > +    return ret;
> > +}
> > +
> > +static void vmc_state(SPICE_GNUC_UNUSED SpiceCharDeviceInstance *sin,
> > +                      SPICE_GNUC_UNUSED int connected)
> > +{
> > +}
> > +
> > +static SpiceCharDeviceInterface vmc_interface = {
> > +    .base.type          = SPICE_INTERFACE_CHAR_DEVICE,
> > +    .base.description   = "test spice virtual channel char device",
> > +    .base.major_version = SPICE_INTERFACE_CHAR_DEVICE_MAJOR,
> > +    .base.minor_version = SPICE_INTERFACE_CHAR_DEVICE_MINOR,
> > +    .state              = vmc_state,
> > +    .write              = vmc_write,
> > +    .read               = vmc_read,
> >  };
> >  
> >  SpiceCharDeviceInstance vmc_instance = {
> > @@ -63,7 +116,7 @@ int main(void)
> >      core = basic_event_loop_init();
> >      test = test_new(core);
> >  
> > -    vmc_instance.base.sif = &base;
> > +    vmc_instance.base.sif = &vmc_interface.base;
> >      spice_server_add_interface(test->server, &vmc_instance.base);
> >  
> >      ping_timer = core->timer_add(pinger, NULL);
> 
> How did you discover this problem?

> This test were supposed to be working even without vmc_read, why now
> is needed? It's not exactly a stub (like "return -1").
> Maybe NULLs are fine too?

s/SpiceBaseInstance/SpiceCharDeviceInstance/ was found because the test
was crashing at start. vmc_read implementation is the same as the one
which was present before 93b4f4050. Arguably, it's not really useful as
then the test just loops forever on vmc_read, but I'd say that's a
different issue (and actually I don't really know what the test is
supposed to be testing /o\ )
Without a vmc_read implementation, you get a crash when trying to read
from the device in vdi_port_read_one_msg_from_device(). There used to be
an assert when one of the vfuncs was missing, which alos caused me to
add this.

Christophe
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