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fix(ja4ebpf): remove double bswap16 on accept4 port

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The manual byte assembly (sa_buf[2]<<8 | sa_buf[3]) already produces
a host-byte-order port value; __builtin_bswap16 was swapping it again,
causing SSL events to use wrong source ports and preventing TLS/HTTP
session correlation.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This commit is contained in:
Jacquin Antoine
2026-04-15 02:57:29 +02:00
parent 61addc8cfa
commit e25caa85da
1 changed files with 4 additions and 4 deletions
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8
services/ja4ebpf/bpf/uprobe_ssl.c
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@ -227,11 +227,11 @@ int kretprobe_accept4_exit(struct sys_exit_accept4_ctx *ctx)
bpf_probe_read_user(sa_buf, sizeof(sa_buf), (void *)sockaddr_ptr); bpf_probe_read_user(sa_buf, sizeof(sa_buf), (void *)sockaddr_ptr);
/* Extraire port (octets 2-3) et adresse IP (octets 4-7) */ /* Extraire port (octets 2-3) et adresse IP (octets 4-7) */
__u16 sin_port = (__u16)(sa_buf[2] << 8) | sa_buf[3]; /* network byte order */ __u16 sin_port = (__u16)(sa_buf[2] << 8) | sa_buf[3]; /* already host byte order (manual assembly) */
__u32 sin_addr = *(__u32 *)(sa_buf + 4); /* network byte order */ __u32 sin_addr = *(__u32 *)(sa_buf + 4); /* network byte order (raw memory read) */
__u32 src_ip = __builtin_bswap32(sin_addr); /* host byte order */ __u32 src_ip = __builtin_bswap32(sin_addr); /* network → host byte order */
__u16 src_port = __builtin_bswap16(sin_port); /* host byte order */ __u16 src_port = sin_port; /* already host byte order */
__u32 fd = (__u32)new_fd; __u32 fd = (__u32)new_fd;
/* Peupler accept_map[{pid_tgid, fd}] */ /* Peupler accept_map[{pid_tgid, fd}] */