// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2020 Facebook */
#include "bpf_iter.h"
#include "bpf_tracing_net.h"
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_endian.h>
char _license[] SEC("license") = "GPL";
static int hlist_unhashed_lockless(const struct hlist_node *h)
{
return !(h->pprev);
}
static int timer_pending(const struct timer_list * timer)
{
return !hlist_unhashed_lockless(&timer->entry);
}
extern unsigned CONFIG_HZ __kconfig;
#define USER_HZ 100
#define NSEC_PER_SEC 1000000000ULL
static clock_t jiffies_to_clock_t(unsigned long x)
{
/* The implementation here tailored to a particular
* setting of USER_HZ.
*/
u64 tick_nsec = (NSEC_PER_SEC + CONFIG_HZ/2) / CONFIG_HZ;
u64 user_hz_nsec = NSEC_PER_SEC / USER_HZ;
if ((tick_nsec % user_hz_nsec) == 0) {
if (CONFIG_HZ < USER_HZ)
return x * (USER_HZ / CONFIG_HZ);
else
return x / (CONFIG_HZ / USER_HZ);
}
return x * tick_nsec/user_hz_nsec;
}
static clock_t jiffies_delta_to_clock_t(long delta)
{
if (delta <= 0)
return 0;
return jiffies_to_clock_t(delta);
}
static long sock_i_ino(const struct sock *sk)
{
const struct socket *sk_socket = sk->sk_socket;
const struct inode *inode;
unsigned long ino;
if (!sk_socket)
return 0;
inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
return ino;
}
static bool
inet_csk_in_pingpong_mode(const struct inet_connection_sock *icsk)
{
return icsk->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
}
static bool tcp_in_initial_slowstart(const struct tcp_sock *tcp)
{
return tcp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
}
static int dump_tcp_sock(struct seq_file *seq, struct tcp_sock *tp,
uid_t uid, __u32 seq_num)
{
const struct inet_connection_sock *icsk;
const struct fastopen_queue *fastopenq;
const struct inet_sock *inet;
unsigned long timer_expires;
const struct sock *sp;
__u16 destp, srcp;
__be32 dest, src;
int timer_active;
int rx_queue;
int state;
icsk = &tp->inet_conn;
inet = &icsk->icsk_inet;
sp = &inet->sk;
fastopenq = &icsk->icsk_accept_queue.fastopenq;
dest = inet->inet_daddr;
src = inet->inet_rcv_saddr;
destp = bpf_ntohs(inet->inet_dport);
srcp = bpf_ntohs(inet->inet_sport);
if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
timer_active = 1;
timer_expires = icsk->icsk_timeout;
} else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
timer_active = 4;
timer_expires = icsk->icsk_timeout;
} else if (timer_pending(&sp->sk_timer)) {
timer_active = 2;
timer_expires = sp->sk_timer.expires;
} else {
timer_active = 0;
timer_expires = bpf_jiffies64();
}
state = sp->sk_state;
if (state == TCP_LISTEN) {
rx_queue = sp->sk_ack_backlog;
} else {
rx_queue = tp->rcv_nxt - tp->copied_seq;
if (rx_queue < 0)
rx_queue = 0;
}
BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
seq_num, src, srcp, dest, destp);
BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d ",
state,
tp->write_seq - tp->snd_una, rx_queue,
timer_active,
jiffies_delta_to_clock_t(timer_expires - bpf_jiffies64()),
icsk->icsk_retransmits, uid,
icsk->icsk_probes_out,
sock_i_ino(sp),
sp->sk_refcnt.refs.counter);
BPF_SEQ_PRINTF(seq, "%pK %lu %lu %u %u %d\n",
tp,
jiffies_to_clock_t(icsk->icsk_rto),
jiffies_to_clock_t(icsk->icsk_ack.ato),
(icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(icsk),
tp->snd_cwnd,
state == TCP_LISTEN ? fastopenq->max_qlen
: (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
);
return 0;
}
static int dump_tw_sock(struct seq_file *seq, struct tcp_timewait_sock *ttw,
uid_t uid, __u32 seq_num)
{
struct inet_timewait_sock *tw = &ttw->tw_sk;
__u16 destp, srcp;
__be32 dest, src;
long delta;
delta = tw->tw_timer.expires - bpf_jiffies64();
dest = tw->tw_daddr;
src = tw->tw_rcv_saddr;
destp = bpf_ntohs(tw->tw_dport);
srcp = bpf_ntohs(tw->tw_sport);
BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
seq_num, src, srcp, dest, destp);
BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
tw->tw_substate, 0, 0,
3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
tw->tw_refcnt.refs.counter, tw);
return 0;
}
static int dump_req_sock(struct seq_file *seq, struct tcp_request_sock *treq,
uid_t uid, __u32 seq_num)
{
struct inet_request_sock *irsk = &treq->req;
struct request_sock *req = &irsk->req;
long ttd;
ttd = req->rsk_timer.expires - bpf_jiffies64();
if (ttd < 0)
ttd = 0;
BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
seq_num, irsk->ir_loc_addr,
irsk->ir_num, irsk->ir_rmt_addr,
bpf_ntohs(irsk->ir_rmt_port));
BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
TCP_SYN_RECV, 0, 0, 1, jiffies_to_clock_t(ttd),
req->num_timeout, uid, 0, 0, 0, req);
return 0;
}
SEC("iter/tcp")
int dump_tcp4(struct bpf_iter__tcp *ctx)
{
struct sock_common *sk_common = ctx->sk_common;
struct seq_file *seq = ctx->meta->seq;
struct tcp_timewait_sock *tw;
struct tcp_request_sock *req;
struct tcp_sock *tp;
uid_t uid = ctx->uid;
__u32 seq_num;
if (sk_common == (void *)0)
return 0;
seq_num = ctx->meta->seq_num;
if (seq_num == 0)
BPF_SEQ_PRINTF(seq, " sl "
"local_address "
"rem_address "
"st tx_queue rx_queue tr tm->when retrnsmt"
" uid timeout inode\n");
if (sk_common->skc_family != AF_INET)
return 0;
tp = bpf_skc_to_tcp_sock(sk_common);
if (tp)
return dump_tcp_sock(seq, tp, uid, seq_num);
tw = bpf_skc_to_tcp_timewait_sock(sk_common);
if (tw)
return dump_tw_sock(seq, tw, uid, seq_num);
req = bpf_skc_to_tcp_request_sock(sk_common);
if (req)
return dump_req_sock(seq, req, uid, seq_num);
return 0;
}
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