Line data Source code
1 : /*
2 : * optimized ntop, about 10x faster than libc versions [as of 2019]
3 : *
4 : * Copyright (c) 2019 David Lamparter, for NetDEF, Inc.
5 : *
6 : * Permission to use, copy, modify, and distribute this software for any
7 : * purpose with or without fee is hereby granted, provided that the above
8 : * copyright notice and this permission notice appear in all copies.
9 : *
10 : * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 : * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 : * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 : * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 : * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 : * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 : * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 : */
18 :
19 : #ifdef HAVE_CONFIG_H
20 : #include "config.h"
21 : #endif
22 :
23 : #include <stdio.h>
24 : #include <stdint.h>
25 : #include <stdbool.h>
26 : #include <string.h>
27 : #include <sys/socket.h>
28 : #include <netinet/in.h>
29 : #include <arpa/inet.h>
30 :
31 : #include "compiler.h"
32 :
33 : #define pos (*posx)
34 :
35 : static inline void putbyte(uint8_t bytex, char **posx)
36 : __attribute__((always_inline)) OPTIMIZE;
37 :
38 380 : static inline void putbyte(uint8_t bytex, char **posx)
39 : {
40 380 : bool zero = false;
41 380 : int byte = bytex, tmp, a, b;
42 :
43 380 : tmp = byte - 200;
44 380 : if (tmp >= 0) {
45 69 : *pos++ = '2';
46 69 : zero = true;
47 69 : byte = tmp;
48 : } else {
49 311 : tmp = byte - 100;
50 311 : if (tmp >= 0) {
51 96 : *pos++ = '1';
52 96 : zero = true;
53 96 : byte = tmp;
54 : }
55 : }
56 :
57 : /* make sure the compiler knows the value range of "byte" */
58 380 : assume(byte < 100 && byte >= 0);
59 :
60 380 : b = byte % 10;
61 380 : a = byte / 10;
62 380 : if (a || zero) {
63 218 : *pos++ = '0' + a;
64 218 : *pos++ = '0' + b;
65 : } else
66 162 : *pos++ = '0' + b;
67 : }
68 :
69 : static inline void puthex(uint16_t word, char **posx)
70 : __attribute__((always_inline)) OPTIMIZE;
71 :
72 128 : static inline void puthex(uint16_t word, char **posx)
73 : {
74 128 : const char *digits = "0123456789abcdef";
75 128 : if (word >= 0x1000)
76 71 : *pos++ = digits[(word >> 12) & 0xf];
77 128 : if (word >= 0x100)
78 75 : *pos++ = digits[(word >> 8) & 0xf];
79 128 : if (word >= 0x10)
80 79 : *pos++ = digits[(word >> 4) & 0xf];
81 128 : *pos++ = digits[word & 0xf];
82 : }
83 :
84 : #undef pos
85 :
86 : const char *frr_inet_ntop(int af, const void * restrict src,
87 : char * restrict dst, socklen_t size)
88 : __attribute__((flatten)) OPTIMIZE;
89 :
90 164 : const char *frr_inet_ntop(int af, const void * restrict src,
91 : char * restrict dst, socklen_t size)
92 : {
93 164 : const uint8_t *b = src;
94 : /* 8 * "abcd:" for IPv6
95 : * note: the IPv4-embedded IPv6 syntax is only used for ::A.B.C.D,
96 : * which isn't longer than 40 chars either. even with ::ffff:A.B.C.D
97 : * it's shorter.
98 : */
99 164 : char buf[8 * 5], *o = buf;
100 164 : size_t best = 0, bestlen = 0, curlen = 0, i;
101 :
102 164 : switch (af) {
103 : case AF_INET:
104 95 : inet4:
105 95 : putbyte(b[0], &o);
106 95 : *o++ = '.';
107 95 : putbyte(b[1], &o);
108 95 : *o++ = '.';
109 95 : putbyte(b[2], &o);
110 95 : *o++ = '.';
111 95 : putbyte(b[3], &o);
112 95 : *o++ = '\0';
113 95 : break;
114 : case AF_INET6:
115 621 : for (i = 0; i < 8; i++) {
116 552 : if (b[i * 2] || b[i * 2 + 1]) {
117 128 : if (curlen && curlen > bestlen) {
118 22 : best = i - curlen;
119 22 : bestlen = curlen;
120 : }
121 128 : curlen = 0;
122 128 : continue;
123 : }
124 424 : curlen++;
125 : }
126 69 : if (curlen && curlen > bestlen) {
127 47 : best = i - curlen;
128 47 : bestlen = curlen;
129 : }
130 : /* do we want ::ffff:A.B.C.D? */
131 69 : if (best == 0 && bestlen == 6) {
132 0 : *o++ = ':';
133 0 : *o++ = ':';
134 0 : b += 12;
135 0 : goto inet4;
136 : }
137 69 : if (bestlen == 1)
138 0 : bestlen = 0;
139 :
140 621 : for (i = 0; i < 8; i++) {
141 552 : if (bestlen && i == best) {
142 69 : if (i == 0)
143 6 : *o++ = ':';
144 69 : *o++ = ':';
145 69 : continue;
146 : }
147 483 : if (i > best && i < best + bestlen) {
148 355 : continue;
149 : }
150 128 : puthex((b[i * 2] << 8) | b[i * 2 + 1], &o);
151 :
152 128 : if (i < 7)
153 106 : *o++ = ':';
154 : }
155 69 : *o++ = '\0';
156 69 : break;
157 : default:
158 : return NULL;
159 : }
160 :
161 164 : i = o - buf;
162 164 : if (i > size)
163 : return NULL;
164 : /* compiler might inline memcpy if it knows the length is short,
165 : * although neither gcc nor clang actually do this currently [2019]
166 : */
167 164 : assume(i <= 8 * 5);
168 164 : memcpy(dst, buf, i);
169 164 : return dst;
170 : }
171 :
172 : #if !defined(INET_NTOP_NO_OVERRIDE) && !defined(__APPLE__)
173 : /* we want to override libc inet_ntop, but make sure it shows up in backtraces
174 : * as frr_inet_ntop (to avoid confusion while debugging)
175 : */
176 : const char *inet_ntop(int af, const void *src, char *dst, socklen_t size)
177 : __attribute__((alias ("frr_inet_ntop")));
178 : #endif
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