1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Generic network code. Moved from net.c
4 *
5 * Copyright 1994 - 2000 Neil Russell.
6 * Copyright 2000 Roland Borde
7 * Copyright 2000 Paolo Scaffardi
8 * Copyright 2000-2002 Wolfgang Denk, wd@denx.de
9 * Copyright 2009 Dirk Behme, dirk.behme@googlemail.com
10 */
11
12 #include <net.h>
13 #include <net6.h>
14 #include <vsprintf.h>
15
string_to_ip(const char * s)16 struct in_addr string_to_ip(const char *s)
17 {
18 struct in_addr addr;
19 char *e;
20 int i;
21
22 addr.s_addr = 0;
23 if (s == NULL)
24 return addr;
25
26 for (addr.s_addr = 0, i = 0; i < 4; ++i) {
27 ulong val = s ? dectoul(s, &e) : 0;
28 if (val > 255) {
29 addr.s_addr = 0;
30 return addr;
31 }
32 if (i != 3 && *e != '.') {
33 addr.s_addr = 0;
34 return addr;
35 }
36 addr.s_addr <<= 8;
37 addr.s_addr |= (val & 0xFF);
38 if (s) {
39 s = (*e) ? e+1 : e;
40 }
41 }
42
43 addr.s_addr = htonl(addr.s_addr);
44 return addr;
45 }
46
47 #if IS_ENABLED(CONFIG_IPV6)
string_to_ip6(const char * str,size_t len,struct in6_addr * addr)48 int string_to_ip6(const char *str, size_t len, struct in6_addr *addr)
49 {
50 int colon_count = 0;
51 int found_double_colon = 0;
52 int xstart = 0; /* first zero (double colon) */
53 int section_num = 7; /* num words the double colon represents */
54 int i;
55 const char *s = str;
56 const char *const e = s + len;
57 struct in_addr zero_ip = {.s_addr = 0};
58
59 if (!str)
60 return -1;
61
62 /* First pass, verify the syntax and locate the double colon */
63 while (s < e) {
64 while (s < e && isxdigit((int)*s))
65 s++;
66 if (*s == '\0')
67 break;
68 if (*s != ':') {
69 if (*s == '.' && section_num >= 2) {
70 struct in_addr v4;
71
72 while (s != str && *(s - 1) != ':')
73 --s;
74 v4 = string_to_ip(s);
75 if (memcmp(&zero_ip, &v4,
76 sizeof(struct in_addr)) != 0) {
77 section_num -= 2;
78 break;
79 }
80 }
81 /* This could be a valid address */
82 break;
83 }
84 if (s == str) {
85 /* The address begins with a colon */
86 if (*++s != ':')
87 /* Must start with a double colon or a number */
88 goto out_err;
89 } else {
90 s++;
91 if (found_double_colon)
92 section_num--;
93 else
94 xstart++;
95 }
96
97 if (*s == ':') {
98 if (found_double_colon)
99 /* Two double colons are not allowed */
100 goto out_err;
101 found_double_colon = 1;
102 section_num -= xstart;
103 s++;
104 }
105
106 if (++colon_count == 7)
107 /* Found all colons */
108 break;
109 ++s;
110 }
111
112 if (colon_count == 0)
113 goto out_err;
114 if (*--s == ':')
115 section_num++;
116
117 /* Second pass, read the address */
118 s = str;
119 for (i = 0; i < 8; i++) {
120 int val = 0;
121 char *end;
122
123 if (found_double_colon &&
124 i >= xstart && i < xstart + section_num) {
125 addr->s6_addr16[i] = 0;
126 continue;
127 }
128 while (*s == ':')
129 s++;
130
131 if (i == 6 && isdigit((int)*s)) {
132 struct in_addr v4 = string_to_ip(s);
133
134 if (memcmp(&zero_ip, &v4,
135 sizeof(struct in_addr)) != 0) {
136 /* Ending with :IPv4-address */
137 addr->s6_addr32[3] = v4.s_addr;
138 break;
139 }
140 }
141
142 val = simple_strtoul(s, &end, 16);
143 if (end != e && *end != '\0' && *end != ':')
144 goto out_err;
145 addr->s6_addr16[i] = htons(val);
146 s = end;
147 }
148 return 0;
149
150 out_err:
151 return -1;
152 }
153 #endif
154
ip_to_string(struct in_addr x,char * s)155 void ip_to_string(struct in_addr x, char *s)
156 {
157 x.s_addr = ntohl(x.s_addr);
158 sprintf(s, "%d.%d.%d.%d",
159 (int) ((x.s_addr >> 24) & 0xff),
160 (int) ((x.s_addr >> 16) & 0xff),
161 (int) ((x.s_addr >> 8) & 0xff),
162 (int) ((x.s_addr >> 0) & 0xff)
163 );
164 }
165
string_to_enetaddr(const char * addr,uint8_t * enetaddr)166 void string_to_enetaddr(const char *addr, uint8_t *enetaddr)
167 {
168 char *end;
169 int i;
170
171 if (!enetaddr)
172 return;
173
174 for (i = 0; i < 6; ++i) {
175 enetaddr[i] = addr ? hextoul(addr, &end) : 0;
176 if (addr)
177 addr = (*end) ? end + 1 : end;
178 }
179 }
180
compute_ip_checksum(const void * vptr,uint nbytes)181 uint compute_ip_checksum(const void *vptr, uint nbytes)
182 {
183 int sum, oddbyte;
184 const unsigned short *ptr = vptr;
185
186 sum = 0;
187 while (nbytes > 1) {
188 sum += *ptr++;
189 nbytes -= 2;
190 }
191 if (nbytes == 1) {
192 oddbyte = 0;
193 ((u8 *)&oddbyte)[0] = *(u8 *)ptr;
194 ((u8 *)&oddbyte)[1] = 0;
195 sum += oddbyte;
196 }
197 sum = (sum >> 16) + (sum & 0xffff);
198 sum += (sum >> 16);
199 sum = ~sum & 0xffff;
200
201 return sum;
202 }
203
add_ip_checksums(uint offset,uint sum,uint new)204 uint add_ip_checksums(uint offset, uint sum, uint new)
205 {
206 ulong checksum;
207
208 sum = ~sum & 0xffff;
209 new = ~new & 0xffff;
210 if (offset & 1) {
211 /*
212 * byte-swap the sum if it came from an odd offset; since the
213 * computation is endian-independent this works.
214 */
215 new = ((new >> 8) & 0xff) | ((new << 8) & 0xff00);
216 }
217 checksum = sum + new;
218 if (checksum > 0xffff)
219 checksum -= 0xffff;
220
221 return (~checksum) & 0xffff;
222 }
223
ip_checksum_ok(const void * addr,uint nbytes)224 int ip_checksum_ok(const void *addr, uint nbytes)
225 {
226 return !(compute_ip_checksum(addr, nbytes) & 0xfffe);
227 }
228