tools/testing/selftests/bpf/progs/bpf_iter_tcp4.c

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