Commit ec12ab2c authored by Hoyeon Lee's avatar Hoyeon Lee Committed by Martin KaFai Lau
Browse files

selftests/bpf: Replace TCP CC string comparisons with bpf_strncmp 



The connect4_prog and bpf_iter_setsockopt tests duplicate the same
open-coded TCP congestion control string comparison logic. Since
bpf_strncmp() provides the same functionality, use it instead to
avoid repeated open-coded loops.

This change applies only to functional BPF tests and does not affect
the verifier performance benchmarks (veristat.cfg). No functional
changes intended.

Reviewed-by: default avatarAmery Hung <ameryhung@gmail.com>
Signed-off-by: default avatarHoyeon Lee <hoyeon.lee@suse.com>
Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20251115225550.1086693-5-hoyeon.lee@suse.com
parent f700b373

tools/testing/selftests/bpf/progs/bpf_iter_setsockopt.c

+2 −15
Original line number Diff line number Diff line
@@ -18,23 +18,10 @@ 


unsigned short reuse_listen_hport = 0;

unsigned short listen_hport = 0;

char cubic_cc[TCP_CA_NAME_MAX] = "bpf_cubic";

const char cubic_cc[] = "bpf_cubic";

char dctcp_cc[TCP_CA_NAME_MAX] = "bpf_dctcp";

bool random_retry = false;



static bool tcp_cc_eq(const char *a, const char *b)

{

	int i;



	for (i = 0; i < TCP_CA_NAME_MAX; i++) {

		if (a[i] != b[i])

			return false;

		if (!a[i])

			break;

	}



	return true;

}



SEC("iter/tcp")

int change_tcp_cc(struct bpf_iter__tcp *ctx)
@@ -58,7 +45,7 @@ int change_tcp_cc(struct bpf_iter__tcp *ctx) 
			   cur_cc, sizeof(cur_cc)))

		return 0;



	if (!tcp_cc_eq(cur_cc, cubic_cc))

	if (bpf_strncmp(cur_cc, TCP_CA_NAME_MAX, cubic_cc))

		return 0;



	if (random_retry && bpf_get_prandom_u32() % 4 == 1)

tools/testing/selftests/bpf/progs/connect4_prog.c

+8 −13
Original line number Diff line number Diff line
@@ -34,6 +34,9 @@ 
#define SOL_TCP 6

#endif



const char reno[] = "reno";

const char cubic[] = "cubic";



__attribute__ ((noinline)) __weak

int do_bind(struct bpf_sock_addr *ctx)

{
@@ -50,35 +53,27 @@ int do_bind(struct bpf_sock_addr *ctx) 
}



static __inline int verify_cc(struct bpf_sock_addr *ctx,

			      char expected[TCP_CA_NAME_MAX])

			      const char expected[])

{

	char buf[TCP_CA_NAME_MAX];

	int i;



	if (bpf_getsockopt(ctx, SOL_TCP, TCP_CONGESTION, &buf, sizeof(buf)))

		return 1;



	for (i = 0; i < TCP_CA_NAME_MAX; i++) {

		if (buf[i] != expected[i])

	if (bpf_strncmp(buf, TCP_CA_NAME_MAX, expected))

		return 1;

		if (buf[i] == 0)

			break;

	}



	return 0;

}



static __inline int set_cc(struct bpf_sock_addr *ctx)

{

	char reno[TCP_CA_NAME_MAX] = "reno";

	char cubic[TCP_CA_NAME_MAX] = "cubic";



	if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &reno, sizeof(reno)))

	if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, (void *)reno, sizeof(reno)))

		return 1;

	if (verify_cc(ctx, reno))

		return 1;



	if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, &cubic, sizeof(cubic)))

	if (bpf_setsockopt(ctx, SOL_TCP, TCP_CONGESTION, (void *)cubic, sizeof(cubic)))

		return 1;

	if (verify_cc(ctx, cubic))

		return 1;