linux/tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* Copyright (c) 2020 Facebook */
   3#include "bpf_iter.h"
   4#include "bpf_tracing_net.h"
   5#include <bpf/bpf_helpers.h>
   6#include <bpf/bpf_endian.h>
   7
   8char _license[] SEC("license") = "GPL";
   9
  10static int hlist_unhashed_lockless(const struct hlist_node *h)
  11{
  12        return !(h->pprev);
  13}
  14
  15static int timer_pending(const struct timer_list * timer)
  16{
  17        return !hlist_unhashed_lockless(&timer->entry);
  18}
  19
  20extern unsigned CONFIG_HZ __kconfig;
  21
  22#define USER_HZ         100
  23#define NSEC_PER_SEC    1000000000ULL
  24static clock_t jiffies_to_clock_t(unsigned long x)
  25{
  26        /* The implementation here tailored to a particular
  27         * setting of USER_HZ.
  28         */
  29        u64 tick_nsec = (NSEC_PER_SEC + CONFIG_HZ/2) / CONFIG_HZ;
  30        u64 user_hz_nsec = NSEC_PER_SEC / USER_HZ;
  31
  32        if ((tick_nsec % user_hz_nsec) == 0) {
  33                if (CONFIG_HZ < USER_HZ)
  34                        return x * (USER_HZ / CONFIG_HZ);
  35                else
  36                        return x / (CONFIG_HZ / USER_HZ);
  37        }
  38        return x * tick_nsec/user_hz_nsec;
  39}
  40
  41static clock_t jiffies_delta_to_clock_t(long delta)
  42{
  43        if (delta <= 0)
  44                return 0;
  45
  46        return jiffies_to_clock_t(delta);
  47}
  48
  49static long sock_i_ino(const struct sock *sk)
  50{
  51        const struct socket *sk_socket = sk->sk_socket;
  52        const struct inode *inode;
  53        unsigned long ino;
  54
  55        if (!sk_socket)
  56                return 0;
  57
  58        inode = &container_of(sk_socket, struct socket_alloc, socket)->vfs_inode;
  59        bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
  60        return ino;
  61}
  62
  63static bool
  64inet_csk_in_pingpong_mode(const struct inet_connection_sock *icsk)
  65{
  66        return icsk->icsk_ack.pingpong >= TCP_PINGPONG_THRESH;
  67}
  68
  69static bool tcp_in_initial_slowstart(const struct tcp_sock *tcp)
  70{
  71        return tcp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
  72}
  73
  74static int dump_tcp_sock(struct seq_file *seq, struct tcp_sock *tp,
  75                         uid_t uid, __u32 seq_num)
  76{
  77        const struct inet_connection_sock *icsk;
  78        const struct fastopen_queue *fastopenq;
  79        const struct inet_sock *inet;
  80        unsigned long timer_expires;
  81        const struct sock *sp;
  82        __u16 destp, srcp;
  83        __be32 dest, src;
  84        int timer_active;
  85        int rx_queue;
  86        int state;
  87
  88        icsk = &tp->inet_conn;
  89        inet = &icsk->icsk_inet;
  90        sp = &inet->sk;
  91        fastopenq = &icsk->icsk_accept_queue.fastopenq;
  92
  93        dest = inet->inet_daddr;
  94        src = inet->inet_rcv_saddr;
  95        destp = bpf_ntohs(inet->inet_dport);
  96        srcp = bpf_ntohs(inet->inet_sport);
  97
  98        if (icsk->icsk_pending == ICSK_TIME_RETRANS ||
  99            icsk->icsk_pending == ICSK_TIME_REO_TIMEOUT ||
 100            icsk->icsk_pending == ICSK_TIME_LOSS_PROBE) {
 101                timer_active = 1;
 102                timer_expires = icsk->icsk_timeout;
 103        } else if (icsk->icsk_pending == ICSK_TIME_PROBE0) {
 104                timer_active = 4;
 105                timer_expires = icsk->icsk_timeout;
 106        } else if (timer_pending(&sp->sk_timer)) {
 107                timer_active = 2;
 108                timer_expires = sp->sk_timer.expires;
 109        } else {
 110                timer_active = 0;
 111                timer_expires = bpf_jiffies64();
 112        }
 113
 114        state = sp->sk_state;
 115        if (state == TCP_LISTEN) {
 116                rx_queue = sp->sk_ack_backlog;
 117        } else {
 118                rx_queue = tp->rcv_nxt - tp->copied_seq;
 119                if (rx_queue < 0)
 120                        rx_queue = 0;
 121        }
 122
 123        BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
 124                       seq_num, src, srcp, dest, destp);
 125        BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5u %8d %lu %d ",
 126                       state,
 127                       tp->write_seq - tp->snd_una, rx_queue,
 128                       timer_active,
 129                       jiffies_delta_to_clock_t(timer_expires - bpf_jiffies64()),
 130                       icsk->icsk_retransmits, uid,
 131                       icsk->icsk_probes_out,
 132                       sock_i_ino(sp),
 133                       sp->sk_refcnt.refs.counter);
 134        BPF_SEQ_PRINTF(seq, "%pK %lu %lu %u %u %d\n",
 135                       tp,
 136                       jiffies_to_clock_t(icsk->icsk_rto),
 137                       jiffies_to_clock_t(icsk->icsk_ack.ato),
 138                       (icsk->icsk_ack.quick << 1) | inet_csk_in_pingpong_mode(icsk),
 139                       tp->snd_cwnd,
 140                       state == TCP_LISTEN ? fastopenq->max_qlen
 141                                : (tcp_in_initial_slowstart(tp) ? -1 : tp->snd_ssthresh)
 142                      );
 143
 144        return 0;
 145}
 146
 147static int dump_tw_sock(struct seq_file *seq, struct tcp_timewait_sock *ttw,
 148                        uid_t uid, __u32 seq_num)
 149{
 150        struct inet_timewait_sock *tw = &ttw->tw_sk;
 151        __u16 destp, srcp;
 152        __be32 dest, src;
 153        long delta;
 154
 155        delta = tw->tw_timer.expires - bpf_jiffies64();
 156        dest = tw->tw_daddr;
 157        src  = tw->tw_rcv_saddr;
 158        destp = bpf_ntohs(tw->tw_dport);
 159        srcp  = bpf_ntohs(tw->tw_sport);
 160
 161        BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
 162                       seq_num, src, srcp, dest, destp);
 163
 164        BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
 165                       tw->tw_substate, 0, 0,
 166                       3, jiffies_delta_to_clock_t(delta), 0, 0, 0, 0,
 167                       tw->tw_refcnt.refs.counter, tw);
 168
 169        return 0;
 170}
 171
 172static int dump_req_sock(struct seq_file *seq, struct tcp_request_sock *treq,
 173                         uid_t uid, __u32 seq_num)
 174{
 175        struct inet_request_sock *irsk = &treq->req;
 176        struct request_sock *req = &irsk->req;
 177        long ttd;
 178
 179        ttd = req->rsk_timer.expires - bpf_jiffies64();
 180
 181        if (ttd < 0)
 182                ttd = 0;
 183
 184        BPF_SEQ_PRINTF(seq, "%4d: %08X:%04X %08X:%04X ",
 185                       seq_num, irsk->ir_loc_addr,
 186                       irsk->ir_num, irsk->ir_rmt_addr,
 187                       bpf_ntohs(irsk->ir_rmt_port));
 188        BPF_SEQ_PRINTF(seq, "%02X %08X:%08X %02X:%08lX %08X %5d %8d %d %d %pK\n",
 189                       TCP_SYN_RECV, 0, 0, 1, jiffies_to_clock_t(ttd),
 190                       req->num_timeout, uid, 0, 0, 0, req);
 191
 192        return 0;
 193}
 194
 195SEC("iter/tcp")
 196int dump_tcp4(struct bpf_iter__tcp *ctx)
 197{
 198        struct sock_common *sk_common = ctx->sk_common;
 199        struct seq_file *seq = ctx->meta->seq;
 200        struct tcp_timewait_sock *tw;
 201        struct tcp_request_sock *req;
 202        struct tcp_sock *tp;
 203        uid_t uid = ctx->uid;
 204        __u32 seq_num;
 205
 206        if (sk_common == (void *)0)
 207                return 0;
 208
 209        seq_num = ctx->meta->seq_num;
 210        if (seq_num == 0)
 211                BPF_SEQ_PRINTF(seq, "  sl  "
 212                                    "local_address "
 213                                    "rem_address   "
 214                                    "st tx_queue rx_queue tr tm->when retrnsmt"
 215                                    "   uid  timeout inode\n");
 216
 217        if (sk_common->skc_family != AF_INET)
 218                return 0;
 219
 220        tp = bpf_skc_to_tcp_sock(sk_common);
 221        if (tp)
 222                return dump_tcp_sock(seq, tp, uid, seq_num);
 223
 224        tw = bpf_skc_to_tcp_timewait_sock(sk_common);
 225        if (tw)
 226                return dump_tw_sock(seq, tw, uid, seq_num);
 227
 228        req = bpf_skc_to_tcp_request_sock(sk_common);
 229        if (req)
 230                return dump_req_sock(seq, req, uid, seq_num);
 231
 232        return 0;
 233}
 234