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87a1e1e0 MT |
1 | /*############################################################################# |
2 | # # | |
3 | # IPFire.org - A linux based firewall # | |
4 | # Copyright (C) 2023 IPFire Network Development Team # | |
5 | # # | |
6 | # This program is free software: you can redistribute it and/or modify # | |
7 | # it under the terms of the GNU General Public License as published by # | |
8 | # the Free Software Foundation, either version 3 of the License, or # | |
9 | # (at your option) any later version. # | |
10 | # # | |
11 | # This program is distributed in the hope that it will be useful, # | |
12 | # but WITHOUT ANY WARRANTY; without even the implied warranty of # | |
13 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # | |
14 | # GNU General Public License for more details. # | |
15 | # # | |
16 | # You should have received a copy of the GNU General Public License # | |
17 | # along with this program. If not, see <http://www.gnu.org/licenses/>. # | |
18 | # # | |
19 | #############################################################################*/ | |
20 | ||
f650f6cd | 21 | #include <net/if.h> |
87a1e1e0 MT |
22 | #include <stddef.h> |
23 | #include <stdlib.h> | |
f650f6cd | 24 | #include <string.h> |
87a1e1e0 | 25 | |
766f08ca MT |
26 | #include <systemd/sd-netlink.h> |
27 | ||
87a1e1e0 MT |
28 | #include "daemon.h" |
29 | #include "link.h" | |
766f08ca | 30 | #include "links.h" |
eaf649ee | 31 | #include "logging.h" |
f650f6cd | 32 | #include "string.h" |
87a1e1e0 MT |
33 | |
34 | struct nw_link { | |
2361667e | 35 | nw_daemon* daemon; |
87a1e1e0 MT |
36 | int nrefs; |
37 | ||
38 | // Interface Index | |
39 | int ifindex; | |
f650f6cd MT |
40 | |
41 | // Interface Name | |
42 | char ifname[IF_NAMESIZE]; | |
f37df5ea MT |
43 | |
44 | // MTU | |
45 | uint32_t mtu; | |
46 | uint32_t min_mtu; | |
47 | uint32_t max_mtu; | |
c65300b4 MT |
48 | |
49 | // Flags | |
50 | unsigned int flags; | |
87a1e1e0 MT |
51 | }; |
52 | ||
2361667e | 53 | int nw_link_create(nw_link** link, nw_daemon* daemon, int ifindex) { |
87a1e1e0 | 54 | // Allocate a new object |
2361667e | 55 | nw_link* l = calloc(1, sizeof(*l)); |
87a1e1e0 MT |
56 | if (!l) |
57 | return 1; | |
58 | ||
59 | // Store a reference to the daemon | |
60 | l->daemon = nw_daemon_ref(daemon); | |
61 | ||
62 | // Initialize the reference counter | |
63 | l->nrefs = 1; | |
64 | ||
65 | // Store the ifindex | |
66 | l->ifindex = ifindex; | |
67 | ||
766f08ca MT |
68 | DEBUG("New link allocated (ifindex = %d)\n", l->ifindex); |
69 | ||
87a1e1e0 MT |
70 | *link = l; |
71 | ||
72 | return 0; | |
73 | } | |
74 | ||
2361667e | 75 | static void nw_link_free(nw_link* link) { |
766f08ca MT |
76 | DEBUG("Freeing link (ifindex = %d)\n", link->ifindex); |
77 | ||
87a1e1e0 MT |
78 | if (link->daemon) |
79 | nw_daemon_unref(link->daemon); | |
80 | } | |
81 | ||
2361667e | 82 | nw_link* nw_link_ref(nw_link* link) { |
87a1e1e0 MT |
83 | link->nrefs++; |
84 | ||
85 | return link; | |
86 | } | |
87 | ||
2361667e | 88 | nw_link* nw_link_unref(nw_link* link) { |
87a1e1e0 MT |
89 | if (--link->nrefs > 0) |
90 | return link; | |
91 | ||
92 | nw_link_free(link); | |
93 | return NULL; | |
94 | } | |
eaf649ee | 95 | |
2361667e | 96 | int nw_link_ifindex(nw_link* link) { |
766f08ca MT |
97 | return link->ifindex; |
98 | } | |
eaf649ee | 99 | |
2361667e | 100 | static int nw_link_update_ifname(nw_link* link, sd_netlink_message* message) { |
f650f6cd MT |
101 | const char* ifname = NULL; |
102 | int r; | |
103 | ||
104 | r = sd_netlink_message_read_string(message, IFLA_IFNAME, &ifname); | |
105 | if (r < 0) { | |
106 | ERROR("Could not read link name for link %d: %m\n", link->ifindex); | |
107 | return 1; | |
108 | } | |
109 | ||
110 | // Do nothing if the name is already set | |
111 | if (strcmp(link->ifname, ifname) == 0) | |
112 | return 0; | |
113 | ||
114 | // Otherwise update the name | |
115 | r = nw_string_set(link->ifname, ifname); | |
116 | if (r) { | |
117 | ERROR("Could not set link name: %m\n"); | |
118 | return 1; | |
119 | } | |
120 | ||
121 | DEBUG("Link %d has been renamed to '%s'\n", link->ifindex, link->ifname); | |
122 | ||
123 | return 0; | |
124 | } | |
125 | ||
2361667e | 126 | static int nw_link_update_mtu(nw_link* link, sd_netlink_message* message) { |
f37df5ea MT |
127 | uint32_t mtu = 0; |
128 | uint32_t min_mtu = 0; | |
129 | uint32_t max_mtu = 0; | |
130 | int r; | |
131 | ||
132 | // Read the MTU | |
133 | r = sd_netlink_message_read_u32(message, IFLA_MTU, &mtu); | |
134 | if (r < 0) { | |
135 | ERROR("Could not read MTU for link %d: %m\n", link->ifindex); | |
136 | return r; | |
137 | } | |
138 | ||
139 | // Read the minimum MTU | |
140 | r = sd_netlink_message_read_u32(message, IFLA_MIN_MTU, &min_mtu); | |
141 | if (r < 0) { | |
142 | ERROR("Could not read the minimum MTU for link %d: %m\n", link->ifindex); | |
143 | return r; | |
144 | } | |
145 | ||
146 | // Read the maximum MTU | |
147 | r = sd_netlink_message_read_u32(message, IFLA_MAX_MTU, &max_mtu); | |
148 | if (r < 0) { | |
149 | ERROR("Could not read the maximum MTU for link %d: %m\n", link->ifindex); | |
150 | return r; | |
151 | } | |
152 | ||
153 | // Set the maximum MTU to infinity | |
154 | if (!max_mtu) | |
155 | max_mtu = UINT32_MAX; | |
156 | ||
157 | // Store min/max MTU | |
158 | link->min_mtu = min_mtu; | |
159 | link->max_mtu = max_mtu; | |
160 | ||
161 | // End here, if the MTU has not been changed | |
162 | if (link->mtu == mtu) | |
163 | return 0; | |
164 | ||
165 | DEBUG("Link %d: MTU has changed to %" PRIu32 " (min: %" PRIu32 ", max: %" PRIu32 ")\n", | |
166 | link->ifindex, link->mtu, link->min_mtu, link->max_mtu); | |
167 | ||
168 | // Store MTU | |
169 | link->mtu = mtu; | |
170 | ||
171 | return 0; | |
172 | } | |
173 | ||
c65300b4 MT |
174 | static int nw_link_update_flags(nw_link* link, sd_netlink_message* message) { |
175 | unsigned int flags = 0; | |
176 | int r; | |
177 | ||
178 | // Fetch flags | |
179 | r = sd_rtnl_message_link_get_flags(message, &flags); | |
180 | if (r < 0) { | |
181 | return DEBUG("Could not read link flags: %m\n"); | |
182 | return 1; | |
183 | } | |
184 | ||
185 | // End here if there have been no changes | |
186 | if (link->flags == flags) | |
187 | return 0; | |
188 | ||
189 | // XXX We should log any changes here | |
190 | ||
191 | // Store the new flags | |
192 | link->flags = flags; | |
193 | ||
194 | return 0; | |
195 | } | |
196 | ||
f650f6cd MT |
197 | /* |
198 | This function is called whenever anything changes, so that we can | |
199 | update our internal link object. | |
200 | */ | |
2361667e | 201 | static int nw_link_update(nw_link* link, sd_netlink_message* message) { |
f650f6cd MT |
202 | int r; |
203 | ||
204 | // Update the interface name | |
205 | r = nw_link_update_ifname(link, message); | |
206 | if (r) | |
207 | return r; | |
208 | ||
f37df5ea MT |
209 | // Update the MTU |
210 | r = nw_link_update_mtu(link, message); | |
211 | if (r) | |
212 | return r; | |
213 | ||
c65300b4 MT |
214 | // Update flags |
215 | r = nw_link_update_flags(link, message); | |
216 | if (r) | |
217 | return r; | |
218 | ||
f650f6cd MT |
219 | return 0; |
220 | } | |
221 | ||
766f08ca | 222 | int nw_link_process(sd_netlink* rtnl, sd_netlink_message* message, void* data) { |
2361667e MT |
223 | nw_links* links = NULL; |
224 | nw_link* link = NULL; | |
766f08ca MT |
225 | const char* ifname = NULL; |
226 | int ifindex; | |
227 | uint16_t type; | |
228 | int r; | |
229 | ||
2361667e | 230 | nw_daemon* daemon = (nw_daemon*)data; |
766f08ca MT |
231 | |
232 | // Fetch links | |
233 | links = nw_daemon_links(daemon); | |
234 | if (!links) { | |
235 | r = 1; | |
236 | goto ERROR; | |
237 | } | |
238 | ||
239 | // Check if this message could be received | |
240 | if (sd_netlink_message_is_error(message)) { | |
241 | r = sd_netlink_message_get_errno(message); | |
242 | if (r < 0) | |
243 | ERROR("Could not receive link message: %m\n"); | |
244 | ||
245 | goto IGNORE; | |
246 | } | |
247 | ||
248 | // Fetch the message type | |
249 | r = sd_netlink_message_get_type(message, &type); | |
250 | if (r < 0) { | |
251 | ERROR("Could not fetch message type: %m\n"); | |
252 | goto IGNORE; | |
253 | } | |
254 | ||
255 | // Check type | |
256 | switch (type) { | |
257 | case RTM_NEWLINK: | |
258 | case RTM_DELLINK: | |
259 | break; | |
260 | ||
261 | default: | |
262 | ERROR("Received an unexpected message (type %u)\n", type); | |
263 | goto IGNORE; | |
264 | } | |
265 | ||
266 | // Fetch the interface index | |
267 | r = sd_rtnl_message_link_get_ifindex(message, &ifindex); | |
268 | if (r < 0) { | |
269 | ERROR("Could not fetch ifindex: %m\n"); | |
270 | goto IGNORE; | |
271 | } | |
272 | ||
273 | // Check interface index | |
274 | if (ifindex <= 0) { | |
275 | ERROR("Received an invalid ifindex\n"); | |
276 | goto IGNORE; | |
277 | } | |
278 | ||
279 | // Fetch the interface name | |
280 | r = sd_netlink_message_read_string(message, IFLA_IFNAME, &ifname); | |
281 | if (r < 0) { | |
282 | ERROR("Received a netlink message without interface name: %m\n"); | |
283 | goto IGNORE; | |
284 | } | |
285 | ||
286 | // Try finding an existing link | |
287 | link = nw_daemon_get_link_by_ifindex(daemon, ifindex); | |
288 | ||
289 | switch (type) { | |
290 | case RTM_NEWLINK: | |
291 | // If the link doesn't exist, create it | |
292 | if (!link) { | |
293 | r = nw_link_create(&link, daemon, ifindex); | |
294 | if (r) { | |
295 | ERROR("Could not create link: %m\n"); | |
296 | goto ERROR; | |
297 | } | |
b8a1a68c MT |
298 | |
299 | // Add it to the list | |
300 | r = nw_links_add_link(links, link); | |
301 | if (r) | |
302 | goto ERROR; | |
766f08ca MT |
303 | } |
304 | ||
f650f6cd MT |
305 | // Import any data from the netlink message |
306 | r = nw_link_update(link, message); | |
307 | if (r) | |
308 | goto ERROR; | |
766f08ca | 309 | |
766f08ca MT |
310 | break; |
311 | ||
312 | case RTM_DELLINK: | |
313 | if (link) | |
314 | nw_links_drop_link(links, link); | |
315 | ||
316 | break; | |
317 | } | |
318 | ||
319 | IGNORE: | |
320 | r = 0; | |
321 | ||
322 | ERROR: | |
323 | if (links) | |
324 | nw_links_unref(links); | |
325 | if (link) | |
326 | nw_link_unref(link); | |
327 | ||
328 | return r; | |
eaf649ee | 329 | } |