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ebpf: Fix RSS error handling

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calculate_rss_hash() was using hash value 0 to tell if it calculated
a hash, but the hash value may be 0 on a rare occasion. Have a
distinct bool value for correctness.

Fixes: f3fa412de2 ("ebpf: Added eBPF RSS program.")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Akihiko Odaki 2024-04-28 16:00:58 +09:00 committed by Jason Wang
parent a4c960eedc
commit 72fa42cfca
2 changed files with 610 additions and 620 deletions
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1210
ebpf/rss.bpf.skeleton.h
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File diff suppressed because it is too large Load Diff

20
tools/ebpf/rss.bpf.c
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@ -380,18 +380,19 @@ error:
return err; return err;
} }
static inline __u32 calculate_rss_hash(struct __sk_buff *skb, static inline bool calculate_rss_hash(struct __sk_buff *skb,
struct rss_config_t *config, struct toeplitz_key_data_t *toe) struct rss_config_t *config,
struct toeplitz_key_data_t *toe,
__u32 *result)
{ {
__u8 rss_input[HASH_CALCULATION_BUFFER_SIZE] = {}; __u8 rss_input[HASH_CALCULATION_BUFFER_SIZE] = {};
size_t bytes_written = 0; size_t bytes_written = 0;
__u32 result = 0;
int err = 0; int err = 0;
struct packet_hash_info_t packet_info = {}; struct packet_hash_info_t packet_info = {};
err = parse_packet(skb, &packet_info); err = parse_packet(skb, &packet_info);
if (err) { if (err) {
return 0; return false;
} }
if (packet_info.is_ipv4) { if (packet_info.is_ipv4) {
@ -524,11 +525,13 @@ static inline __u32 calculate_rss_hash(struct __sk_buff *skb,
} }
} }
if (bytes_written) { if (!bytes_written) {
net_toeplitz_add(&result, rss_input, bytes_written, toe); return false;
} }
return result; net_toeplitz_add(result, rss_input, bytes_written, toe);
return true;
} }
SEC("socket") SEC("socket")
@ -549,8 +552,7 @@ int tun_rss_steering_prog(struct __sk_buff *skb)
return config->default_queue; return config->default_queue;
} }
hash = calculate_rss_hash(skb, config, toe); if (calculate_rss_hash(skb, config, toe, &hash)) {
if (hash) {
__u32 table_idx = hash % config->indirections_len; __u32 table_idx = hash % config->indirections_len;
__u16 *queue = 0; __u16 *queue = 0;