Pau Espin Pedrol | f5fbb41 | 2019-08-21 18:49:44 +0200 | [diff] [blame] | 1 | #include "sgsn.h" |
| 2 | #include "ggsn.h" |
| 3 | |
| 4 | |
| 5 | static bool sgsn_peer_attempt_free(struct sgsn_peer *sgsn) |
| 6 | { |
| 7 | /* We have to be careful here, since if all pdp ctx for that sgsn were |
| 8 | deactivated in-between we sent the Echo Req and receivied the timeout |
| 9 | indication, the sgsn (cbp) may be already gone. We need to add some |
| 10 | counter reference of echo requets in flight and only free sgsn |
| 11 | structures when it goes to zero decreased for all Echo Resp. We do it |
| 12 | this way because currently in libgtp there's no understanding of "gsn |
| 13 | peer" for which messages are grouped and hence we cannot request |
| 14 | libgtp to drop all queued messages for a specific peer. */ |
| 15 | if (sgsn->tx_msgs_queued) { |
| 16 | LOGSGSN(LOGL_INFO, sgsn, "Delaying delete, still %u echo messages queued\n", |
| 17 | sgsn->tx_msgs_queued); |
| 18 | return false; |
| 19 | } |
| 20 | llist_del(&sgsn->entry); |
| 21 | LOGSGSN(LOGL_INFO, sgsn, "Deleting SGSN\n"); |
| 22 | talloc_free(sgsn); |
| 23 | return true; |
| 24 | } |
| 25 | |
| 26 | static void sgsn_peer_echo_req(struct sgsn_peer *sgsn) |
| 27 | { |
| 28 | struct ggsn_ctx *ggsn = sgsn->ggsn; |
| 29 | LOGSGSN(LOGL_INFO, sgsn, "Tx Echo Request\n"); |
| 30 | gtp_echo_req(ggsn->gsn, sgsn->gtp_version, sgsn, &sgsn->addr); |
| 31 | sgsn->tx_msgs_queued++; |
| 32 | } |
| 33 | |
| 34 | void sgsn_peer_echo_resp(struct sgsn_peer *sgsn, bool timeout) |
| 35 | { |
| 36 | if (timeout) { |
| 37 | LOGSGSN(LOGL_NOTICE, sgsn, "Rx Echo Request timed out!\n"); |
| 38 | sgsn_peer_drop_all_pdp(sgsn); |
| 39 | } else { |
| 40 | LOGSGSN(LOGL_INFO, sgsn, "Rx Echo Response\n"); |
| 41 | } |
| 42 | |
| 43 | /* We decrement it here after dropping all pdps to make sure sgsn was |
| 44 | not freed upon last pdp ctx deleted and is still alive now */ |
| 45 | sgsn->tx_msgs_queued--; |
| 46 | if (llist_empty(&sgsn->pdp_list)) |
| 47 | sgsn_peer_attempt_free(sgsn); |
| 48 | } |
| 49 | |
| 50 | void sgsn_echo_timer_start(struct sgsn_peer *sgsn) |
| 51 | { |
| 52 | if (sgsn->ggsn->cfg.echo_interval == 0) |
| 53 | return; |
| 54 | sgsn_peer_echo_req(sgsn); |
| 55 | osmo_timer_schedule(&sgsn->echo_timer, sgsn->ggsn->cfg.echo_interval, 0); |
| 56 | } |
| 57 | |
| 58 | void sgsn_echo_timer_stop(struct sgsn_peer *sgsn) |
| 59 | { |
| 60 | osmo_timer_del(&sgsn->echo_timer); |
| 61 | } |
| 62 | |
| 63 | static void sgsn_echo_timer_cb(void *data) |
| 64 | { |
| 65 | struct sgsn_peer *sgsn = (struct sgsn_peer *) data; |
| 66 | sgsn_echo_timer_start(sgsn); |
| 67 | } |
| 68 | |
| 69 | struct sgsn_peer *sgsn_peer_allocate(struct ggsn_ctx *ggsn, struct in_addr *ia, unsigned int gtp_version) |
| 70 | { |
| 71 | struct sgsn_peer *sgsn; |
| 72 | |
| 73 | sgsn = talloc_zero_size(ggsn, sizeof(struct sgsn_peer)); |
| 74 | sgsn->ggsn = ggsn; |
| 75 | sgsn->addr = *ia; |
| 76 | sgsn->gtp_version = gtp_version; |
| 77 | sgsn->remote_restart_ctr = -1; |
| 78 | INIT_LLIST_HEAD(&sgsn->pdp_list); |
| 79 | INIT_LLIST_HEAD(&sgsn->entry); |
| 80 | |
| 81 | osmo_timer_setup(&sgsn->echo_timer, sgsn_echo_timer_cb, sgsn); |
| 82 | |
| 83 | LOGSGSN(LOGL_INFO, sgsn, "Discovered\n"); |
| 84 | return sgsn; |
| 85 | } |
| 86 | |
| 87 | void sgsn_peer_add_pdp_priv(struct sgsn_peer *sgsn, struct pdp_priv_t *pdp_priv) |
| 88 | { |
| 89 | bool was_empty = llist_empty(&sgsn->pdp_list); |
| 90 | pdp_priv->sgsn = sgsn; |
| 91 | llist_add(&pdp_priv->entry, &sgsn->pdp_list); |
| 92 | if (was_empty) |
| 93 | sgsn_echo_timer_start(sgsn); |
| 94 | } |
| 95 | |
| 96 | void sgsn_peer_remove_pdp_priv(struct pdp_priv_t* pdp_priv) |
| 97 | { |
| 98 | struct sgsn_peer *sgsn = pdp_priv->sgsn; |
| 99 | llist_del(&pdp_priv->entry); |
| 100 | if (sgsn && llist_empty(&sgsn->pdp_list)) { |
| 101 | /* No PDP contexts associated to this SGSN, no need to keep it */ |
| 102 | sgsn_echo_timer_stop(sgsn); |
| 103 | /* sgsn may not be freed if there are some messages still queued |
| 104 | in libgtp which could return a pointer to it */ |
| 105 | sgsn_peer_attempt_free(sgsn); |
| 106 | } |
| 107 | |
| 108 | pdp_priv->sgsn = NULL; |
| 109 | } |
| 110 | |
| 111 | /* High-level function to be called in case a GGSN has disappeared or |
| 112 | * otherwise lost state (recovery procedure). It will detach all related pdp ctx |
| 113 | * from a ggsn and communicate deact to MS. Optionally (!NULL), one pdp ctx can |
| 114 | * be kept alive to allow handling later message which contained the Recovery IE. */ |
| 115 | static unsigned int sgsn_peer_drop_all_pdp_except(struct sgsn_peer *sgsn, struct pdp_priv_t *except) |
| 116 | { |
| 117 | unsigned int num = 0; |
| 118 | char buf[INET_ADDRSTRLEN]; |
| 119 | |
| 120 | inet_ntop(AF_INET, &sgsn->addr, buf, sizeof(buf)); |
| 121 | |
| 122 | struct pdp_priv_t *pdp, *pdp2; |
| 123 | llist_for_each_entry_safe(pdp, pdp2, &sgsn->pdp_list, entry) { |
| 124 | if (pdp == except) |
| 125 | continue; |
| 126 | ggsn_close_one_pdp(pdp->lib); |
| 127 | num++; |
| 128 | } |
| 129 | |
| 130 | /* Note: if except is NULL, all pdp contexts are freed and sgsn is |
| 131 | already freed at this point */ |
| 132 | LOGP(DGGSN, LOGL_INFO, "SGSN(%s) Dropped %u PDP contexts\n", buf, num); |
| 133 | |
| 134 | return num; |
| 135 | } |
| 136 | |
| 137 | unsigned int sgsn_peer_drop_all_pdp(struct sgsn_peer *sgsn) |
| 138 | { |
| 139 | return sgsn_peer_drop_all_pdp_except(sgsn, NULL); |
| 140 | } |
| 141 | |
| 142 | int sgsn_peer_handle_recovery(struct sgsn_peer *sgsn, struct pdp_t *pdp, uint8_t recovery) |
| 143 | { |
| 144 | struct pdp_priv_t *pdp_priv = NULL; |
| 145 | |
| 146 | if (sgsn->remote_restart_ctr == -1) { |
| 147 | /* First received ECHO RESPONSE, note the restart ctr */ |
| 148 | sgsn->remote_restart_ctr = recovery; |
| 149 | } else if (sgsn->remote_restart_ctr != recovery) { |
| 150 | /* counter has changed (SGSN restart): release all PDP */ |
| 151 | LOGSGSN(LOGL_NOTICE, sgsn, "SGSN recovery (%u->%u) pdp=%p, " |
| 152 | "releasing all%s PDP contexts\n", |
| 153 | sgsn->remote_restart_ctr, recovery, pdp, pdp ? " other" : ""); |
| 154 | sgsn->remote_restart_ctr = recovery; |
| 155 | if (pdp) |
| 156 | pdp_priv = pdp->priv; |
| 157 | sgsn_peer_drop_all_pdp_except(sgsn, pdp_priv); |
| 158 | } |
| 159 | return 0; |
| 160 | } |