On 06/05/2014 11:39 AM, Michal Privoznik wrote:
> The purpose of this function is to fetch link state
> and link speed for given NIC name from the SYSFS.
>
> Signed-off-by: Michal Privoznik <mprivozn@xxxxxxxxxx>
> ---
> src/libvirt_private.syms | 1 +
> src/util/virnetdev.c | 104 +++++++++++++++++++++++++++++++++++++++++++++++
> src/util/virnetdev.h | 6 +++
> 3 files changed, 111 insertions(+)
>
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 394c086..6d08ee9 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -1540,6 +1540,7 @@ virNetDevClearIPv4Address;
> virNetDevExists;
> virNetDevGetIndex;
> virNetDevGetIPv4Address;
> +virNetDevGetLinkInfo;
> virNetDevGetMAC;
> virNetDevGetMTU;
> virNetDevGetPhysicalFunction;
> diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
> index 3a60cf7..9d2c0d2 100644
> --- a/src/util/virnetdev.c
> +++ b/src/util/virnetdev.c
> @@ -1832,3 +1832,107 @@ virNetDevRestoreNetConfig(const char *linkdev ATTRIBUTE_UNUSED,
> }
>
> #endif /* defined(__linux__) && defined(HAVE_LIBNL) */
> +
> +#ifdef __linux__
> +# define SYSFS_PREFIX "/sys/class/net/"
There is a 'NET_SYSFS' definition earlier to the same path - seems it
could/should be reused...
NIT: Your definition will create a double slash below for operstate and
speed... Whether that's desired or not is up to you... There's a mix of
usage within libvirt sources.
> +int
> +virNetDevGetLinkInfo(const char *ifname,
> + virInterfaceState *state,
> + unsigned int *speed)
Could there ever be any other stats/data to fetch? Perhaps consider
passing a virInterfaceLinkPtr instead and then reference state/speed off
of it. Then in the future you don't have to keep adding params to the
API. None of the current callers pass NULL for either parameter.
I also wonder if we really want to fail out if we something goes wrong.
It's not like we're affecting the state/speed of the device if something
did go wrong - we're just outputting data if it's there. I guess I'm
thinking more about the callers, but that's a design decision you have
to make and live with. Considering the comment below regarding the bug
with speed - one wonders what else lurks in former formats that the
following code can error out on.
> +{
> + int ret = -1;
> + char *path = NULL;
> + char *buf = NULL;
> + char *tmp;
> + int tmp_state;
s/int/virInterfaceState/
Seems we should be able to set up a dummy /sys/class/net environment in
order to test the new API's... Something I attempted with my recently
posted scsi_host changes.
> + unsigned int tmp_speed;
> +
> + if (state) {
> + if (virAsprintf(&path, SYSFS_PREFIX "%s/operstate", ifname) < 0)
> + goto cleanup;
> +
> + if (virFileReadAll(path, 1024, &buf) < 0) {
> + virReportSystemError(errno,
> + _("unable to read: %s"),
> + path);
> + goto cleanup;
> + }
> +
> + if (!(tmp = strchr(buf, '\n'))) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Unable to parse: %s"),
> + buf);
> + goto cleanup;
> + }
> +
> + *tmp = '\0';
> +
> + /* We shouldn't allow 0 here, because
> + * virInterfaceState enum starts from 1. */
> + if ((tmp_state = virInterfaceStateTypeFromString(buf)) <= 0) {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Unable to parse: %s"),
> + buf);
> + goto cleanup;
> + }
> +
> + *state = tmp_state;
> +
> + VIR_FREE(path);
> + VIR_FREE(buf);
> + }
> +
> + if (speed) {
> + if (virAsprintf(&path, SYSFS_PREFIX "%s/speed", ifname) < 0)
> + goto cleanup;
> +
> + if (virFileReadAll(path, 1024, &buf) < 0) {
> + /* Some devices doesn't report speed, in which case we get EINVAL */
> + if (errno == EINVAL) {
> + ret = 0;
> + goto cleanup;
> + }
> + virReportSystemError(errno,
> + _("unable to read: %s"),
> + path);
> + goto cleanup;
> + }
> +
> + if (virStrToLong_ui(buf, &tmp, 10, &tmp_speed) < 0 ||
> + *tmp != '\n') {
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Unable to parse: %s"),
> + buf);
> + goto cleanup;
> + }
> +
> + /* Workaround broken kernel API. If the link is unplugged then
> + * depending on the NIC driver, link speed can be reported as -1.
> + * However, the value is printed out as unsigned integer instead of
> + * signed one. Terrifying but true. */
> + *speed = (int) tmp_speed == -1 ? 0 : tmp_speed;
> + }
> +
> + ret = 0;
> + cleanup:
> + VIR_FREE(buf);
> + VIR_FREE(path);
> + return ret;
> +}
> +
> +#else
> +
> +int
> +virNetDevGetLinkInfo(const char *ifname,
> + virInterfaceState *state,
> + unsigned int *speed)
In virutil.c each of the paremters has a "ATTRIBUTE_UNUSED" and the code is:
virReportSystemError(ENOSYS, "%s", _("Not supported on this platform"));
return -1;
Your call on how do do this
ACK - in general though based on fixing up the nits/minor issues. I
trust if you change the parameters that it'll be done right or the
compiler will complain!
John
> +{
> + /* Port me */
> + VIR_DEBUG("Getting link info on %s is not implemented on this platform");
> + if (state)
> + *state = 0;
> + if (speed)
> + *speed = 0;
> + return 0;
> +}
> +#endif /* defined(__linux__) */
> diff --git a/src/util/virnetdev.h b/src/util/virnetdev.h
> index 00c82e0..de33323 100644
> --- a/src/util/virnetdev.h
> +++ b/src/util/virnetdev.h
> @@ -29,6 +29,7 @@
> # include "virnetlink.h"
> # include "virmacaddr.h"
> # include "virpci.h"
> +# include "device_conf.h"
>
> # ifdef HAVE_STRUCT_IFREQ
> typedef struct ifreq virIfreq;
> @@ -145,4 +146,9 @@ int virNetDevGetVirtualFunctionInfo(const char *vfname, char **pfname,
> int *vf)
> ATTRIBUTE_NONNULL(1);
>
> +int virNetDevGetLinkInfo(const char *ifname,
> + virInterfaceState *state,
> + unsigned int *speed)
> + ATTRIBUTE_NONNULL(1);
> +
> #endif /* __VIR_NETDEV_H__ */
>
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