net/eth: Report if headers are actually present

The values returned by eth_get_protocols() are used to perform RSS,
checksumming and segmentation. Even when a packet signals the use of the
protocols which these operations can be applied to, the headers for them
may not be present because of too short packet or fragmentation, for
example. In such a case, the operations cannot be applied safely.

Report the presence of headers instead of whether the use of the
protocols are indicated with eth_get_protocols(). This also makes
corresponding changes to the callers of eth_get_protocols() to match
with its new signature and to remove redundant checks for fragmentation.

Fixes: 75020a7021 ("Common definitions for VMWARE devices")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

include/net/eth.h

@@ -391,8 +391,8 @@ typedef struct eth_l4_hdr_info_st {
 } eth_l4_hdr_info;
 
 void eth_get_protocols(const struct iovec *iov, int iovcnt,
-                       bool *isip4, bool *isip6,
-                       bool *isudp, bool *istcp,
+                       bool *hasip4, bool *hasip6,
+                       bool *hasudp, bool *hastcp,
                        size_t *l3hdr_off,
                        size_t *l4hdr_off,
                        size_t *l5hdr_off,