Neels Hofmeyr | a75d1c2 | 2019-11-20 03:35:37 +0100 | [diff] [blame] | 1 | /* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de> |
| 2 | * |
| 3 | * All Rights Reserved |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU Affero General Public License as published by |
| 7 | * the Free Software Foundation; either version 3 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU Affero General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU Affero General Public License |
| 16 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 17 | * |
| 18 | */ |
| 19 | |
| 20 | #include <stdlib.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | #include <osmocom/mslookup/mslookup.h> |
| 24 | #include <osmocom/mslookup/mdns.h> |
| 25 | #include <osmocom/hlr/logging.h> |
| 26 | #include <osmocom/hlr/hlr.h> |
| 27 | #include <osmocom/hlr/mslookup_server.h> |
| 28 | #include <osmocom/hlr/mslookup_server_mdns.h> |
| 29 | |
| 30 | static void osmo_mslookup_server_mdns_tx(struct osmo_mslookup_server_mdns *server, |
| 31 | uint16_t packet_id, |
| 32 | const struct osmo_mslookup_query *query, |
| 33 | const struct osmo_mslookup_result *result) |
| 34 | { |
| 35 | struct msgb *msg; |
| 36 | const char *errmsg = NULL; |
| 37 | void *ctx = talloc_named_const(server, 0, __func__); |
| 38 | |
| 39 | msg = osmo_mdns_result_encode(ctx, packet_id, query, result, server->domain_suffix); |
| 40 | if (!msg) |
| 41 | errmsg = "Error encoding mDNS answer packet"; |
| 42 | else if (osmo_mdns_sock_send(server->sock, msg)) |
| 43 | errmsg = "Error sending mDNS answer"; |
| 44 | if (errmsg) |
| 45 | LOGP(DMSLOOKUP, LOGL_ERROR, "%s: mDNS: %s\n", osmo_mslookup_result_name_c(ctx, query, result), errmsg); |
| 46 | talloc_free(ctx); |
| 47 | } |
| 48 | |
| 49 | static void osmo_mslookup_server_mdns_handle_request(uint16_t packet_id, |
| 50 | struct osmo_mslookup_server_mdns *server, |
| 51 | const struct osmo_mslookup_query *query) |
| 52 | { |
| 53 | struct osmo_mslookup_result result; |
| 54 | |
| 55 | mslookup_server_rx(query, &result); |
| 56 | /* Error logging already happens in mslookup_server_rx() */ |
| 57 | if (result.rc != OSMO_MSLOOKUP_RC_RESULT) |
| 58 | return; |
| 59 | |
| 60 | osmo_mslookup_server_mdns_tx(server, packet_id, query, &result); |
| 61 | } |
| 62 | |
| 63 | static int osmo_mslookup_server_mdns_rx(struct osmo_fd *osmo_fd, unsigned int what) |
| 64 | { |
| 65 | struct osmo_mslookup_server_mdns *server = osmo_fd->data; |
| 66 | struct osmo_mslookup_query *query; |
| 67 | uint16_t packet_id; |
| 68 | int n; |
| 69 | uint8_t buffer[1024]; |
| 70 | void *ctx; |
| 71 | |
| 72 | /* Parse the message and print it */ |
| 73 | n = read(osmo_fd->fd, buffer, sizeof(buffer)); |
| 74 | if (n < 0) |
| 75 | return n; |
| 76 | |
| 77 | ctx = talloc_named_const(server, 0, __func__); |
| 78 | query = osmo_mdns_query_decode(ctx, buffer, n, &packet_id, server->domain_suffix); |
| 79 | if (!query) { |
| 80 | talloc_free(ctx); |
| 81 | return -1; |
| 82 | } |
| 83 | |
| 84 | osmo_mslookup_id_name_buf((char *)buffer, sizeof(buffer), &query->id); |
| 85 | LOGP(DMSLOOKUP, LOGL_DEBUG, "mDNS rx request: %s.%s\n", query->service, buffer); |
| 86 | osmo_mslookup_server_mdns_handle_request(packet_id, server, query); |
| 87 | talloc_free(ctx); |
| 88 | return n; |
| 89 | } |
| 90 | |
| 91 | struct osmo_mslookup_server_mdns *osmo_mslookup_server_mdns_start(void *ctx, const struct osmo_sockaddr_str *bind_addr, |
| 92 | const char *domain_suffix) |
| 93 | { |
| 94 | struct osmo_mslookup_server_mdns *server = talloc_zero(ctx, struct osmo_mslookup_server_mdns); |
| 95 | OSMO_ASSERT(server); |
| 96 | *server = (struct osmo_mslookup_server_mdns){ |
| 97 | .bind_addr = *bind_addr, |
| 98 | .domain_suffix = talloc_strdup(server, domain_suffix) |
| 99 | }; |
| 100 | |
| 101 | server->sock = osmo_mdns_sock_init(server, |
| 102 | bind_addr->ip, bind_addr->port, |
| 103 | osmo_mslookup_server_mdns_rx, |
| 104 | server, 0); |
| 105 | if (!server->sock) { |
| 106 | LOGP(DMSLOOKUP, LOGL_ERROR, |
| 107 | "mslookup mDNS server: error initializing multicast bind on " OSMO_SOCKADDR_STR_FMT "\n", |
| 108 | OSMO_SOCKADDR_STR_FMT_ARGS(bind_addr)); |
| 109 | talloc_free(server); |
| 110 | return NULL; |
| 111 | } |
| 112 | |
| 113 | return server; |
| 114 | } |
| 115 | |
| 116 | void osmo_mslookup_server_mdns_stop(struct osmo_mslookup_server_mdns *server) |
| 117 | { |
| 118 | if (!server) |
| 119 | return; |
| 120 | osmo_mdns_sock_cleanup(server->sock); |
| 121 | talloc_free(server); |
| 122 | } |
| 123 | |
| 124 | void mslookup_server_mdns_config_apply() |
| 125 | { |
| 126 | /* Check whether to start/stop/restart mDNS server */ |
| 127 | bool should_run; |
| 128 | bool should_stop; |
| 129 | |
| 130 | should_run = g_hlr->mslookup.allow_startup |
| 131 | && g_hlr->mslookup.server.enable && g_hlr->mslookup.server.mdns.enable; |
| 132 | should_stop = g_hlr->mslookup.server.mdns.running |
| 133 | && (!should_run |
| 134 | || osmo_sockaddr_str_cmp(&g_hlr->mslookup.server.mdns.bind_addr, |
| 135 | &g_hlr->mslookup.server.mdns.running->bind_addr) |
| 136 | || strcmp(g_hlr->mslookup.server.mdns.domain_suffix, |
| 137 | g_hlr->mslookup.server.mdns.running->domain_suffix)); |
| 138 | |
| 139 | if (should_stop) { |
| 140 | osmo_mslookup_server_mdns_stop(g_hlr->mslookup.server.mdns.running); |
| 141 | g_hlr->mslookup.server.mdns.running = NULL; |
| 142 | LOGP(DMSLOOKUP, LOGL_NOTICE, "Stopped mslookup mDNS server\n"); |
| 143 | } |
| 144 | |
| 145 | if (should_run && !g_hlr->mslookup.server.mdns.running) { |
| 146 | g_hlr->mslookup.server.mdns.running = |
| 147 | osmo_mslookup_server_mdns_start(g_hlr, &g_hlr->mslookup.server.mdns.bind_addr, |
| 148 | g_hlr->mslookup.server.mdns.domain_suffix); |
| 149 | if (!g_hlr->mslookup.server.mdns.running) |
| 150 | LOGP(DMSLOOKUP, LOGL_ERROR, "Failed to start mslookup mDNS server on " OSMO_SOCKADDR_STR_FMT "\n", |
| 151 | OSMO_SOCKADDR_STR_FMT_ARGS(&g_hlr->mslookup.server.mdns.bind_addr)); |
| 152 | else |
| 153 | LOGP(DMSLOOKUP, LOGL_NOTICE, "Started mslookup mDNS server, receiving mDNS requests at multicast " |
| 154 | OSMO_SOCKADDR_STR_FMT "\n", |
| 155 | OSMO_SOCKADDR_STR_FMT_ARGS(&g_hlr->mslookup.server.mdns.running->bind_addr)); |
| 156 | } |
| 157 | } |