On Thu, May 24, 2018 at 12:08:31PM -0700, William Tu wrote:
> On Thu, May 24, 2018 at 10:20 AM, Ben Pfaff <[email protected]> wrote:
> > On Thu, May 24, 2018 at 05:36:10AM -0700, William Tu wrote:
> >> On Wed, May 23, 2018 at 7:13 PM, Darrell Ball <[email protected]> wrote:
> >> > The struct erspan_metadata is updated to replace the 'version'
> >> > placeholder with the erspan base hdr. Also, the erspan
> >> > index is defined explicitly as ovs_16aligned_be32 to mirror
> >> > its encoding.
> >> > Changes to odp_util result from updating the erspan index
> >> > type.
> >> >
> >> > CC: William Tu <[email protected]>
> >> > Fixes: 068794b43f0e ("erspan: Add flow-based erspan options")
> >> > Signed-off-by: Darrell Ball <[email protected]>
> >> > ---
> >> > lib/odp-util.c | 36 ++++++++++++++++++++----------------
> >> > lib/packets.h | 6 +++---
> >> > 2 files changed, 23 insertions(+), 19 deletions(-)
> >> >
> >> > diff --git a/lib/odp-util.c b/lib/odp-util.c
> >> > index 105ac80..767281f 100644
> >> > --- a/lib/odp-util.c
> >> > +++ b/lib/odp-util.c
> >> > @@ -2786,9 +2786,9 @@ odp_tun_key_from_attr__(const struct nlattr *attr,
> >> > bool is_mask,
> >> >
> >> > memcpy(&opts, nl_attr_get(a), attr_len);
> >> >
> >> > - tun->erspan_ver = opts.version;
> >> > + tun->erspan_ver = opts.bh.ver;
> >> > if (tun->erspan_ver == 1) {
> >> > - tun->erspan_idx = ntohl(opts.u.index);
> >> > + tun->erspan_idx =
> >> > ntohl(get_16aligned_be32(&opts.u.index));
> >> > } else if (tun->erspan_ver == 2) {
> >> > tun->erspan_dir = opts.u.md2.dir;
> >> > tun->erspan_hwid = get_hwid(&opts.u.md2);
> >> > @@ -2890,10 +2890,11 @@ tun_key_to_attr(struct ofpbuf *a, const struct
> >> > flow_tnl *tun_key,
> >> > !strcmp(tnl_type, "ip6erspan")) &&
> >> > (tun_key->erspan_ver == 1 || tun_key->erspan_ver == 2)) {
> >> > struct erspan_metadata opts;
> >> > + memset(&opts, 0, sizeof opts);
> >> >
> >> > - opts.version = tun_key->erspan_ver;
> >> > - if (opts.version == 1) {
> >> > - opts.u.index = htonl(tun_key->erspan_idx);
> >> > + opts.bh.ver = tun_key->erspan_ver;
> >> > + if (opts.bh.ver == 1) {
> >> > + put_16aligned_be32(&opts.u.index,
> >> > htonl(tun_key->erspan_idx));
> >> > } else {
> >> > opts.u.md2.dir = tun_key->erspan_dir;
> >> > set_hwid(&opts.u.md2, tun_key->erspan_hwid);
> >> > @@ -3368,22 +3369,23 @@ format_odp_tun_erspan_opt(const struct nlattr
> >> > *attr,
> >> > opts = nl_attr_get(attr);
> >> > mask = mask_attr ? nl_attr_get(mask_attr) : NULL;
> >> >
> >> > - ver = (uint8_t)opts->version;
> >> > + ver = opts->bh.ver;
> >> > if (mask) {
> >> > - ver_ma = (uint8_t)mask->version;
> >> > + ver_ma = mask->bh.ver;
> >> > }
> >> >
> >> > format_u8u(ds, "ver", ver, mask ? &ver_ma : NULL, verbose);
> >> >
> >> > - if (opts->version == 1) {
> >> > + if (opts->bh.ver == 1) {
> >> > if (mask) {
> >> > ds_put_format(ds, "idx=%#"PRIx32"/%#"PRIx32",",
> >> > - ntohl(opts->u.index),
> >> > - ntohl(mask->u.index));
> >> > + ntohl(get_16aligned_be32(&opts->u.index)),
> >> > + ntohl(get_16aligned_be32(&mask->u.index)));
> >> > } else {
> >> > - ds_put_format(ds, "idx=%#"PRIx32",", ntohl(opts->u.index));
> >> > + ds_put_format(ds, "idx=%#"PRIx32",",
> >> > + ntohl(get_16aligned_be32(&opts->u.index)));
> >> > }
> >> > - } else if (opts->version == 2) {
> >> > + } else if (opts->bh.ver == 2) {
> >> > dir = opts->u.md2.dir;
> >> > hwid = opts->u.md2.hwid;
> >> > if (mask) {
> >> > @@ -4859,10 +4861,11 @@ scan_erspan_metadata(const char *s,
> >> >
> >> > if (!strncmp(s, ")", 1)) {
> >> > s += 1;
> >> > - key->version = ver;
> >> > - key->u.index = htonl(idx);
> >> > + memset(&key->bh, 0, sizeof key->bh);
> >> > + key->bh.ver = ver;
> >> > + put_16aligned_be32(&key->u.index, htonl(idx));
> >> > if (mask) {
> >> > - mask->u.index = htonl(idx_mask);
> >> > + put_16aligned_be32(&mask->u.index, htonl(idx_mask));
> >> > }
> >> > }
> >> > return s - s_base;
> >> > @@ -4882,7 +4885,8 @@ scan_erspan_metadata(const char *s,
> >> >
> >> > if (!strncmp(s, ")", 1)) {
> >> > s += 1;
> >> > - key->version = ver;
> >> > + memset(&key->bh, 0, sizeof key->bh);
> >> > + key->bh.ver = ver;
> >> > key->u.md2.hwid = hwid;
> >> > key->u.md2.dir = dir;
> >> > if (mask) {
> >> > diff --git a/lib/packets.h b/lib/packets.h
> >> > index 7645a9d..5c013a3 100644
> >> > --- a/lib/packets.h
> >> > +++ b/lib/packets.h
> >> > @@ -1312,10 +1312,10 @@ struct erspan_md2 {
> >> > };
> >> >
> >> > struct erspan_metadata {
> >> > - int version;
> >> > + struct erspan_base_hdr bh;
> >> > union {
> >> > - ovs_be32 index; /* Version 1 (type II)*/
> >> > - struct erspan_md2 md2; /* Version 2 (type III) */
> >> > + ovs_16aligned_be32 index; /* Version 1 (type II). */
> >> > + struct erspan_md2 md2; /* Version 2 (type III). */
> >> > } u;
> >> > };
> >> >
> >> Thanks for the patch.
> >>
> >> We shouldn't change this header since struct erspan_metadata is exposed
> >> from kernel's UAPI header. (see include/uapi/linux/erspan.h).
> >> OVS kernel module expects this binary format.
> >
> > We often use different data structures in userspace and the kernel.
> > This only changes the userspace one.
> >
> > It's a bad idea to use "int" for wire formats because its size can vary
> > among platforms (although the Linux kernel does rely on it being 32
> > bits, we don't make the same assumption in our userspace).
> >
>
> the 'int version' here is not wire format. It is to determine version 1 or 2
> so that the metadata mode tunnel device knows to whether use
> ovs_be32 index or,
> struct erspan_md2 md2 (which are wire format)
>
> > It's a bad idea to use "ovs_be32" in packet formats, in userspace,
> > because packets aren't always aligned on 32-bit boundaries.
>
> I see. Then I think we should do:
> @@ -1314,7 +1314,7 @@ struct erspan_md2 {
> struct erspan_metadata {
> int version;
> union {
> - ovs_be32 index; /* Version 1 (type II)*/
> + ovs_16aligned_be32 index; /* Version 1 (type II)*/
> struct erspan_md2 md2; /* Version 2 (type III) */
> } u;
> };
OK, now I understand what's going on. This is only used to define the
format of the OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS attribute. Since it's not
a wire format at all, we don't need to use ovs_16aligned_be32 either,
and an "int" is fine too.
Since erspan_metadata is part of the kernel ABI, which is exposed via
Netlink, it should normally be defined by including a kernel header
rather than in packets.h, which normally just defines wire formats for
things. Can we arrange for that to happen?
Thanks,
Ben.
Also, I guess that we could just use the data in-place:
diff --git a/lib/odp-util.c b/lib/odp-util.c
index 105ac809073e..5e858f0f9797 100644
--- a/lib/odp-util.c
+++ b/lib/odp-util.c
@@ -2781,17 +2781,14 @@ odp_tun_key_from_attr__(const struct nlattr *attr, bool
is_mask,
tun_metadata_from_geneve_nlattr(a, is_mask, tun);
break;
case OVS_TUNNEL_KEY_ATTR_ERSPAN_OPTS: {
- int attr_len = nl_attr_get_size(a);
- struct erspan_metadata opts;
+ const struct erspan_metadata *opts = nl_attr_get(a);
- memcpy(&opts, nl_attr_get(a), attr_len);
-
- tun->erspan_ver = opts.version;
+ tun->erspan_ver = opts->version;
if (tun->erspan_ver == 1) {
- tun->erspan_idx = ntohl(opts.u.index);
+ tun->erspan_idx = ntohl(opts->u.index);
} else if (tun->erspan_ver == 2) {
- tun->erspan_dir = opts.u.md2.dir;
- tun->erspan_hwid = get_hwid(&opts.u.md2);
+ tun->erspan_dir = opts->u.md2.dir;
+ tun->erspan_hwid = get_hwid(&opts->u.md2);
} else {
VLOG_WARN("%s invalid erspan version\n", __func__);
}
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
