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Code Issues Releases Wiki Activity

flow: Make assertions about offsets within struct flow easier to follow.

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Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
This commit is contained in:
Ben Pfaff
2015-06-09 11:32:24 -07:00
parent 7d1ced0177
commit 268eca112d
2 changed files with 31 additions and 30 deletions
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58
lib/flow.c
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@@ -50,25 +50,32 @@ const uint8_t flow_segment_u64s[4] = {
FLOW_U64S
};
/* Asserts that field 'f1' follows immediately after 'f0' in struct flow,
* without any intervening padding. */
#define ASSERT_SEQUENTIAL(f0, f1) \
BUILD_ASSERT_DECL(offsetof(struct flow, f0) \
+ MEMBER_SIZEOF(struct flow, f0) \
== offsetof(struct flow, f1))
/* Asserts that fields 'f0' and 'f1' are in the same 32-bit aligned word within
* struct flow. */
#define ASSERT_SAME_WORD(f0, f1) \
BUILD_ASSERT_DECL(offsetof(struct flow, f0) / 4 \
== offsetof(struct flow, f1) / 4)
/* Asserts that 'f0' and 'f1' are both sequential and within the same 32-bit
* aligned word in struct flow. */
#define ASSERT_SEQUENTIAL_SAME_WORD(f0, f1) \
ASSERT_SEQUENTIAL(f0, f1); \
ASSERT_SAME_WORD(f0, f1)
/* miniflow_extract() assumes the following to be true to optimize the
* extraction process. */
BUILD_ASSERT_DECL(offsetof(struct flow, dl_type) + 2
== offsetof(struct flow, vlan_tci) &&
offsetof(struct flow, dl_type) / 4
== offsetof(struct flow, vlan_tci) / 4 );
ASSERT_SEQUENTIAL_SAME_WORD(dl_type, vlan_tci);
BUILD_ASSERT_DECL(offsetof(struct flow, nw_frag) + 3
== offsetof(struct flow, nw_proto) &&
offsetof(struct flow, nw_tos) + 2
== offsetof(struct flow, nw_proto) &&
offsetof(struct flow, nw_ttl) + 1
== offsetof(struct flow, nw_proto) &&
offsetof(struct flow, nw_frag) / 4
== offsetof(struct flow, nw_tos) / 4 &&
offsetof(struct flow, nw_ttl) / 4
== offsetof(struct flow, nw_tos) / 4 &&
offsetof(struct flow, nw_proto) / 4
== offsetof(struct flow, nw_tos) / 4);
ASSERT_SEQUENTIAL_SAME_WORD(nw_frag, nw_tos);
ASSERT_SEQUENTIAL_SAME_WORD(nw_tos, nw_ttl);
ASSERT_SEQUENTIAL_SAME_WORD(nw_ttl, nw_proto);
/* TCP flags in the middle of a BE64, zeroes in the other half. */
BUILD_ASSERT_DECL(offsetof(struct flow, tcp_flags) % 8 == 4);
@@ -80,10 +87,7 @@ BUILD_ASSERT_DECL(offsetof(struct flow, tcp_flags) % 8 == 4);
#define TCP_FLAGS_BE32(tcp_ctl) ((OVS_FORCE ovs_be32)TCP_FLAGS_BE16(tcp_ctl))
#endif
BUILD_ASSERT_DECL(offsetof(struct flow, tp_src) + 2
== offsetof(struct flow, tp_dst) &&
offsetof(struct flow, tp_src) / 4
== offsetof(struct flow, tp_dst) / 4);
ASSERT_SEQUENTIAL_SAME_WORD(tp_src, tp_dst);
/* Removes 'size' bytes from the head end of '*datap', of size '*sizep', which
* must contain at least 'size' bytes of data. Returns the first byte of data
@@ -458,8 +462,7 @@ miniflow_extract(struct dp_packet *packet, struct miniflow *dst)
ovs_be16 vlan_tci;
/* Link layer. */
BUILD_ASSERT(offsetof(struct flow, dl_dst) + 6
== offsetof(struct flow, dl_src));
ASSERT_SEQUENTIAL(dl_dst, dl_src);
miniflow_push_macs(mf, dl_dst, data);
/* dl_type, vlan_tci. */
vlan_tci = parse_vlan(&data, &size);
@@ -645,8 +648,7 @@ miniflow_extract(struct dp_packet *packet, struct miniflow *dst)
}
/* Must be adjacent. */
BUILD_ASSERT(offsetof(struct flow, arp_sha) + 6
== offsetof(struct flow, arp_tha));
ASSERT_SEQUENTIAL(arp_sha, arp_tha);
memcpy(arp_buf[0], arp->ar_sha, ETH_ADDR_LEN);
memcpy(arp_buf[1], arp->ar_tha, ETH_ADDR_LEN);
@@ -1252,12 +1254,8 @@ miniflow_hash_5tuple(const struct miniflow *flow, uint32_t basis)
return hash;
}
BUILD_ASSERT_DECL(offsetof(struct flow, tp_src) + 2
== offsetof(struct flow, tp_dst) &&
offsetof(struct flow, tp_src) / 4
== offsetof(struct flow, tp_dst) / 4);
BUILD_ASSERT_DECL(offsetof(struct flow, ipv6_src) + 16
== offsetof(struct flow, ipv6_dst));
ASSERT_SEQUENTIAL_SAME_WORD(tp_src, tp_dst);
ASSERT_SEQUENTIAL(ipv6_src, ipv6_dst);
/* Calculates the 5-tuple hash from the given flow. */
uint32_t