[LBBS-60] Prevent clients from monopolizing nodes (DOS)
Malicious clients can cause a DOS attack by simply taking up all available nodes. This should be prevented by outright rejecting connections from nodes that have more than X connections or Y connections per certain protocols. Clearly, 60 telnet sessions is overboard.
3 TELNET 0:00:27 <Not Logged In> 175.44.131.4 57943 3335484 81 81 81 81 82 83 -1 N N 80x24? Yes ??? 0 0 N
4 TELNET 0:00:22 <Not Logged In> 175.44.131.4 34233 3335486 84 84 84 84 85 86 -1 N N 80x24? Yes ??? 0 0 N
5 TELNET 0:01:39 <Not Logged In> 175.44.131.4 41502 3335362 87 87 87 87 88 89 -1 N N 80x24? Yes ??? 0 0 N
6 TELNET 0:01:34 <Not Logged In> 175.44.131.4 47237 3335364 90 90 90 90 91 92 -1 N N 80x24? Yes ??? 0 0 N
7 TELNET 0:01:26 <Not Logged In> 175.44.131.4 54521 3335366 93 93 93 93 95 96 -1 N N 80x24? Yes ??? 0 0 N
8 TELNET 0:01:26 <Not Logged In> 175.44.131.4 54531 3335368 94 94 94 94 98 99 -1 N N 80x24? Yes ??? 0 0 N
9 TELNET 0:01:25 <Not Logged In> 175.44.131.4 55516 3335370 97 97 97 97 101 102 -1 N N 80x24? Yes ??? 0 0 N
10 TELNET 0:01:24 <Not Logged In> 175.44.131.4 56007 3335372 100 100 100 100 103 104 -1 N N 80x24? Yes ??? 0 0 N
11 TELNET 0:01:21 <Not Logged In> 175.44.131.4 59979 3335374 105 105 105 105 106 107 -1 N N 80x24? Yes ??? 0 0 N
12 TELNET 0:01:19 <Not Logged In> 175.44.131.4 32896 3335376 108 108 108 108 109 110 -1 N N 80x24? Yes ??? 0 0 N
13 TELNET 0:01:19 <Not Logged In> 175.44.131.4 33849 3335378 111 111 111 111 112 113 -1 N N 80x24? Yes ??? 0 0 N
14 TELNET 0:01:17 <Not Logged In> 175.44.131.4 35936 3335380 114 114 114 114 115 116 -1 N N 80x24? Yes ??? 0 0 N
15 TELNET 0:01:12 <Not Logged In> 175.44.131.4 40350 3335382 117 117 117 117 119 120 -1 N N 80x24? Yes ??? 0 0 N
16 TELNET 0:01:12 <Not Logged In> 175.44.131.4 41017 3335384 118 118 118 118 122 123 -1 N N 80x24? Yes ??? 0 0 N
17 TELNET 0:01:11 <Not Logged In> 175.44.131.4 41206 3335386 121 121 121 121 124 125 -1 N N 80x24? Yes ??? 0 0 N
18 TELNET 0:01:07 <Not Logged In> 175.44.131.4 45834 3335388 126 126 126 126 127 128 -1 N N 80x24? Yes ??? 0 0 N
19 TELNET 0:01:05 <Not Logged In> 175.44.131.4 47712 3335390 129 129 129 129 131 132 -1 N N 80x24? Yes ??? 0 0 N
20 TELNET 0:01:04 <Not Logged In> 175.44.131.4 47864 3335392 130 130 130 130 134 135 -1 N N 80x24? Yes ??? 0 0 N
21 TELNET 0:01:04 <Not Logged In> 175.44.131.4 48427 3335394 133 133 133 133 137 138 -1 N N 80x24? Yes ??? 0 0 N
22 TELNET 0:01:03 <Not Logged In> 175.44.131.4 49062 3335396 136 136 136 136 140 141 -1 N N 80x24? Yes ??? 0 0 N
23 TELNET 0:01:02 <Not Logged In> 175.44.131.4 49893 3335398 139 139 139 139 142 143 -1 N N 80x24? Yes ??? 0 0 N
24 TELNET 0:01:00 <Not Logged In> 175.44.131.4 52735 3335400 144 144 144 144 145 146 -1 N N 80x24? Yes ??? 0 0 N
25 TELNET 0:00:59 <Not Logged In> 175.44.131.4 53903 3335402 147 147 147 147 149 150 -1 N N 80x24? Yes ??? 0 0 N
26 TELNET 0:00:58 <Not Logged In> 175.44.131.4 54288 3335404 148 148 148 148 152 153 -1 N N 80x24? Yes ??? 0 0 N
27 TELNET 0:00:58 <Not Logged In> 175.44.131.4 54572 3335406 151 151 151 151 155 156 -1 N N 80x24? Yes ??? 0 0 N
28 TELNET 0:00:57 <Not Logged In> 175.44.131.4 55186 3335408 154 154 154 154 157 158 -1 N N 80x24? Yes ??? 0 0 N
29 TELNET 0:00:56 <Not Logged In> 175.44.131.4 56944 3335410 159 159 159 159 161 162 -1 N N 80x24? Yes ??? 0 0 N
30 TELNET 0:00:55 <Not Logged In> 175.44.131.4 57237 3335412 160 160 160 160 79 80 -1 N N 80x24? Yes ??? 0 0 N
31 TELNET 0:00:54 <Not Logged In> 175.44.131.4 58545 3335416 163 163 163 163 167 169 -1 N N 80x24? Yes ??? 0 0 N
32 TELNET 0:00:53 <Not Logged In> 175.44.131.4 59182 3335418 166 166 166 166 171 172 -1 N N 80x24? Yes ??? 0 0 N
33 TELNET 0:00:52 <Not Logged In> 175.44.131.4 59277 3335420 170 170 170 170 174 175 -1 N N 80x24? Yes ??? 0 0 N
34 TELNET 0:00:52 <Not Logged In> 175.44.131.4 59791 3335422 173 173 173 173 177 178 -1 N N 80x24? Yes ??? 0 0 N
35 TELNET 0:00:51 <Not Logged In> 175.44.131.4 60024 3335424 176 176 176 176 180 181 -1 N N 80x24? Yes ??? 0 0 N
36 TELNET 0:00:50 <Not Logged In> 175.44.131.4 60518 3335426 179 179 179 179 183 184 -1 N N 80x24? Yes ??? 0 0 N
37 TELNET 0:00:50 <Not Logged In> 175.44.131.4 32819 3335428 182 182 182 182 186 187 -1 N N 80x24? Yes ??? 0 0 N
38 TELNET 0:00:49 <Not Logged In> 175.44.131.4 34391 3335430 185 185 185 185 189 190 -1 N N 80x24? Yes ??? 0 0 N
39 TELNET 0:00:48 <Not Logged In> 175.44.131.4 35226 3335432 188 188 188 188 192 193 -1 N N 80x24? Yes ??? 0 0 N
40 TELNET 0:00:47 <Not Logged In> 175.44.131.4 35272 3335434 191 191 191 191 195 196 -1 N N 80x24? Yes ??? 0 0 N
41 TELNET 0:00:47 <Not Logged In> 175.44.131.4 35563 3335436 194 194 194 194 198 199 -1 N N 80x24? Yes ??? 0 0 N
42 TELNET 0:00:46 <Not Logged In> 175.44.131.4 36483 3335438 197 197 197 197 201 202 -1 N N 80x24? Yes ??? 0 0 N
43 TELNET 0:00:45 <Not Logged In> 175.44.131.4 36839 3335440 200 200 200 200 204 205 -1 N N 80x24? Yes ??? 0 0 N
44 TELNET 0:00:45 <Not Logged In> 175.44.131.4 37103 3335442 203 203 203 203 207 208 -1 N N 80x24? Yes ??? 0 0 N
45 TELNET 0:00:44 <Not Logged In> 175.44.131.4 37538 3335444 206 206 206 206 210 211 -1 N N 80x24? Yes ??? 0 0 N
46 TELNET 0:00:43 <Not Logged In> 175.44.131.4 38048 3335446 209 209 209 209 213 214 -1 N N 80x24? Yes ??? 0 0 N
47 TELNET 0:00:43 <Not Logged In> 175.44.131.4 38324 3335448 212 212 212 212 216 217 -1 N N 80x24? Yes ??? 0 0 N
48 TELNET 0:00:42 <Not Logged In> 175.44.131.4 39434 3335450 215 215 215 215 219 220 -1 N N 80x24? Yes ??? 0 0 N
49 TELNET 0:00:41 <Not Logged In> 175.44.131.4 39482 3335452 218 218 218 218 222 223 -1 N N 80x24? Yes ??? 0 0 N
50 TELNET 0:00:40 <Not Logged In> 175.44.131.4 40341 3335454 221 221 221 221 225 226 -1 N N 80x24? Yes ??? 0 0 N
51 TELNET 0:00:40 <Not Logged In> 175.44.131.4 40416 3335456 224 224 224 224 228 229 -1 N N 80x24? Yes ??? 0 0 N
52 TELNET 0:00:39 <Not Logged In> 175.44.131.4 41496 3335458 227 227 227 227 231 232 -1 N N 80x24? Yes ??? 0 0 N
53 TELNET 0:00:38 <Not Logged In> 175.44.131.4 41505 3335460 230 230 230 230 234 235 -1 N N 80x24? Yes ??? 0 0 N
54 TELNET 0:00:38 <Not Logged In> 175.44.131.4 41909 3335462 233 233 233 233 237 238 -1 N N 80x24? Yes ??? 0 0 N
55 TELNET 0:00:37 <Not Logged In> 175.44.131.4 42319 3335464 236 236 236 236 240 241 -1 N N 80x24? Yes ??? 0 0 N
56 TELNET 0:00:36 <Not Logged In> 175.44.131.4 42328 3335466 239 239 239 239 243 244 -1 N N 80x24? Yes ??? 0 0 N
57 TELNET 0:00:35 <Not Logged In> 175.44.131.4 42726 3335468 242 242 242 242 246 247 -1 N N 80x24? Yes ??? 0 0 N
58 TELNET 0:00:35 <Not Logged In> 175.44.131.4 42779 3335470 245 245 245 245 249 250 -1 N N 80x24? Yes ??? 0 0 N
59 TELNET 0:00:34 <Not Logged In> 175.44.131.4 43932 3335472 248 248 248 248 252 253 -1 N N 80x24? Yes ??? 0 0 N
60 TELNET 0:00:33 <Not Logged In> 175.44.131.4 44061 3335474 251 251 251 251 255 256 -1 N N 80x24? Yes ??? 0 0 N
61 TELNET 0:00:33 <Not Logged In> 175.44.131.4 45436 3335476 254 254 254 254 258 259 -1 N N 80x24? Yes ??? 0 0 N
62 TELNET 0:00:32 <Not Logged In> 175.44.131.4 45901 3335478 257 257 257 257 261 262 -1 N N 80x24? Yes ??? 0 0 N
63 TELNET 0:00:31 <Not Logged In> 175.44.131.4 45485 3335480 260 260 260 260 264 265 -1 N N 80x24? Yes ??? 0 0 N
64 TELNET 0:00:30 <Not Logged In> 175.44.131.4 46428 3335482 263 263 263 263 266 268 -1 N N 80x24? Yes ??? 0 0 N
64 active nodes, 35559 lifetime nodes
[2024-07-31 22:45:02.300] DEBUG[3180520]: socket.c:1067 __bbs_tcp_listener: Accepting new TELNET connection from 175.44.131.4
[2024-07-31 22:45:02.301] WARNING[3180520]: node.c:252 __bbs_node_request: Node request failed since we currently have 64 active nodesComments
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9/20/2024 7:09 AM — InterLinked
Autoresolved by code commit on GitHub:
socket.c: Throttle node connections per IP address.
https://github.com/InterLinked1/lbbs/commit/e2960f5ba86bc93bdfd54c7ab8d97868511f1f89