| File: | lib/libswan/ip_range.c |
| Warning: | line 178, column 3 Value stored to 'afi' is never read |
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| 1 | /* ip_range type, for libreswan |
| 2 | * |
| 3 | * Copyright (C) 2007 Michael Richardson <mcr@xelerance.com> |
| 4 | * Copyright (C) 2000 Henry Spencer. |
| 5 | * Copyright (C) 2013 Antony Antony <antony@phenome.org> |
| 6 | * Copyright (C) 2019 Andrew Cagney <cagney@gnu.org> |
| 7 | * |
| 8 | * This library is free software; you can redistribute it and/or modify it |
| 9 | * under the terms of the GNU Library General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or (at your |
| 11 | * option) any later version. See <https://www.gnu.org/licenses/lgpl-2.1.txt>. |
| 12 | * |
| 13 | * This library is distributed in the hope that it will be useful, but |
| 14 | * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY |
| 15 | * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public |
| 16 | * License for more details. |
| 17 | */ |
| 18 | |
| 19 | /* |
| 20 | * convert from text form of IP address range specification to binary; |
| 21 | * and more minor utilities for mask length calculations for IKEv2 |
| 22 | */ |
| 23 | |
| 24 | #include <string.h> |
| 25 | #include <arpa/inet.h> /* for ntohl() */ |
| 26 | |
| 27 | #include "jambuf.h" |
| 28 | #include "ip_range.h" |
| 29 | #include "ip_info.h" |
| 30 | #include "passert.h" |
| 31 | #include "lswlog.h" /* for pexpect() */ |
| 32 | |
| 33 | const ip_range unset_range; /* all zeros */ |
| 34 | |
| 35 | ip_range range(const ip_address *start, const ip_address *end) |
| 36 | { |
| 37 | /* does the caller know best? */ |
| 38 | const struct ip_info *st = address_type(start); |
| 39 | const struct ip_info *et = address_type(end); |
| 40 | passert(st == et){ _Bool assertion__ = st == et; if (!assertion__) { lsw_passert_fail ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 40}, "%s", "st == et"); } }; |
| 41 | bool_Bool ss = address_is_specified(start); |
| 42 | bool_Bool es = address_is_specified(end); |
| 43 | passert(ss == es){ _Bool assertion__ = ss == es; if (!assertion__) { lsw_passert_fail ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 43}, "%s", "ss == es"); } }; |
| 44 | ip_range r = { |
| 45 | .start = *start, |
| 46 | .end = *end, |
| 47 | }; |
| 48 | return r; |
| 49 | } |
| 50 | |
| 51 | /* |
| 52 | * Calculate the number of significant bits in the size of the range. |
| 53 | * floor(lg(|high-low| + 1)) |
| 54 | * |
| 55 | * ??? this really should use ip_range rather than a pair of ip_address values |
| 56 | */ |
| 57 | |
| 58 | int iprange_bits(ip_address low, ip_address high) |
| 59 | { |
| 60 | const struct ip_info *ht = address_type(&high); |
| 61 | const struct ip_info *lt = address_type(&low); |
| 62 | if (ht == NULL((void*)0) || lt == NULL((void*)0)) { |
| 63 | /* either invalid */ |
| 64 | return -1; |
| 65 | } |
| 66 | if (ht != lt) { |
| 67 | return -1; |
| 68 | } |
| 69 | |
| 70 | shunk_t hs = address_as_shunk(&high); |
| 71 | const uint8_t *hp = hs.ptr; /* cast const void * */ |
| 72 | passert(hs.len > 0){ _Bool assertion__ = hs.len > 0; if (!assertion__) { lsw_passert_fail ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 72}, "%s", "hs.len > 0"); } }; |
| 73 | size_t n = hs.len; |
| 74 | |
| 75 | shunk_t ls = address_as_shunk(&low); |
| 76 | const uint8_t *lp = ls.ptr; /* cast const void * */ |
| 77 | passert(hs.len == ls.len){ _Bool assertion__ = hs.len == ls.len; if (!assertion__) { lsw_passert_fail ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 77}, "%s", "hs.len == ls.len"); } }; |
| 78 | |
| 79 | ip_address diff = low; /* initialize all the contents to sensible values */ |
| 80 | unsigned char *dp; |
| 81 | chunk_t diff_chunk = address_as_chunk(&diff); |
| 82 | dp = diff_chunk.ptr; /* cast void* */ |
| 83 | |
| 84 | unsigned lastnz = n; |
| 85 | |
| 86 | /* subtract: d = h - l */ |
| 87 | int carry = 0; |
| 88 | unsigned j; |
| 89 | for (j = n; j > 0; ) { |
| 90 | j--; |
| 91 | int val = hp[j] - lp[j] - carry; |
| 92 | if (val < 0) { |
| 93 | val += 0x100u; |
| 94 | carry = 1; |
| 95 | } else { |
| 96 | carry = 0; |
| 97 | } |
| 98 | dp[j] = val; |
| 99 | if (val != 0) |
| 100 | lastnz = j; |
| 101 | } |
| 102 | |
| 103 | /* if the answer was negative, complement it */ |
| 104 | if (carry != 0) { |
| 105 | lastnz = n; /* redundant, but not obviously so */ |
| 106 | for (j = n; j > 0; ) { |
| 107 | j--; |
| 108 | int val = 0xFFu - dp[j] + carry; |
| 109 | if (val >= 0x100) { |
| 110 | val -= 0x100; |
| 111 | carry = 1; /* redundant, but not obviously so */ |
| 112 | } else { |
| 113 | carry = 0; |
| 114 | } |
| 115 | dp[j] = val; |
| 116 | if (val != 0) |
| 117 | lastnz = j; |
| 118 | } |
| 119 | } |
| 120 | |
| 121 | /* find leftmost bit in dp[lastnz] */ |
| 122 | unsigned bo = 0; |
| 123 | if (lastnz != n) { |
| 124 | bo = 0; |
| 125 | for (unsigned m = 0x80u; (m & dp[lastnz]) == 0; m >>=1) |
| 126 | bo++; |
| 127 | } |
| 128 | return (n - lastnz) * 8 - bo; |
| 129 | } |
| 130 | |
| 131 | static err_t extract_ends(const char *src, const struct ip_info *afi, ip_range *dst) |
| 132 | { |
| 133 | const char *dash; |
| 134 | const char *high; |
| 135 | size_t hlen; |
| 136 | const char *oops; |
| 137 | size_t srclen = strlen(src); |
| 138 | |
| 139 | dash = memchr(src, '-', srclen); |
| 140 | if (dash == NULL((void*)0)) |
| 141 | return "not ipv4 address range with '-' or ipv6 subnet"; |
| 142 | |
| 143 | high = dash + 1; |
| 144 | hlen = srclen - (high - src); |
| 145 | |
| 146 | /* extract start ip address */ |
| 147 | oops = ttoaddr_num(src, dash - src, afi->af, &dst->start); |
| 148 | if (oops != NULL((void*)0)) |
| 149 | return oops; |
| 150 | |
| 151 | /* extract end ip address */ |
| 152 | oops = ttoaddr_num(high, hlen, afi->af, &dst->end); |
| 153 | if (oops != NULL((void*)0)) |
| 154 | return oops; |
| 155 | |
| 156 | return NULL((void*)0); |
| 157 | } |
| 158 | |
| 159 | /* |
| 160 | * ttorange - convert text v4 "addr1-addr2" to address_start address_end |
| 161 | * v6 allows "subnet/mask" to address_start address_end |
| 162 | */ |
| 163 | err_t ttorange(const char *src, const struct ip_info *afi, ip_range *dst, |
| 164 | struct logger *logger) |
| 165 | { |
| 166 | err_t er = NULL((void*)0); |
| 167 | |
| 168 | zero(dst)memset((dst), '\0', sizeof(*(dst))); |
| 169 | ip_range tmp = *dst; /* clear it */ |
| 170 | |
| 171 | ip_subnet v6_subnet; |
| 172 | er = ttosubnet(src, 0, AF_INET610, '6', &v6_subnet, logger); |
| 173 | if (er == NULL((void*)0)) { |
| 174 | if (v6_subnet.addr.hport != 0) |
| 175 | return "port must be zero for IPv6 addresspool"; |
| 176 | tmp = range_from_subnet(&v6_subnet); |
| 177 | tmp.is_subnet = true1; |
| 178 | afi = &ipv6_info; |
Value stored to 'afi' is never read | |
| 179 | } else { |
| 180 | if (afi == NULL((void*)0)) { |
| 181 | afi = &ipv4_info; |
| 182 | if (extract_ends(src, afi, &tmp) != NULL((void*)0)) { |
| 183 | afi = &ipv6_info; |
| 184 | er = extract_ends(src, afi, &tmp); |
| 185 | if (er != NULL((void*)0)) |
| 186 | return er; /* v4 error is ignored */ |
| 187 | |
| 188 | } |
| 189 | } else { |
| 190 | er = extract_ends(src, afi, &tmp); |
| 191 | if (er != NULL((void*)0)) |
| 192 | return er; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | if (addrcmp(&tmp.start, &tmp.end) > 0) { |
| 197 | return "start of range must not be greater than end"; |
| 198 | } |
| 199 | |
| 200 | if (address_is_any(&tmp.start) || |
| 201 | address_is_any(&tmp.end)) { |
| 202 | return "'0.0.0.0 or ::0' not allowed in range"; |
| 203 | } |
| 204 | |
| 205 | /* We have validated the range. Now put bounds in dst. */ |
| 206 | *dst = tmp; |
| 207 | return NULL((void*)0); |
| 208 | } |
| 209 | |
| 210 | void jam_range(struct jambuf *buf, const ip_range *range) |
| 211 | { |
| 212 | jam_address(buf, &range->start); |
| 213 | if (range_type(range) == &ipv6_info && range->is_subnet) { |
| 214 | ip_subnet tmp_subnet; |
| 215 | rangetosubnet(&range->start, &range->end, &tmp_subnet); |
| 216 | jam(buf, "/%u", tmp_subnet.maskbits); |
| 217 | } else { |
| 218 | jam(buf, "-"); |
| 219 | jam_address(buf, &range->end); |
| 220 | } |
| 221 | } |
| 222 | |
| 223 | const char *str_range(const ip_range *range, range_buf *out) |
| 224 | { |
| 225 | struct jambuf buf = ARRAY_AS_JAMBUF(out->buf)array_as_jambuf((out->buf), sizeof(out->buf)); |
| 226 | jam_range(&buf, range); |
| 227 | return out->buf; |
| 228 | } |
| 229 | |
| 230 | ip_range range_from_subnet(const ip_subnet *subnet) |
| 231 | { |
| 232 | ip_range r = { |
| 233 | /* SHHHHH */ |
| 234 | .start = address_blit(endpoint_address(&subnet->addr), |
| 235 | &keep_bits, &clear_bits, |
| 236 | subnet->maskbits), |
| 237 | .end = address_blit(endpoint_address(&subnet->addr), |
| 238 | &keep_bits, &set_bits, |
| 239 | subnet->maskbits), |
| 240 | }; |
| 241 | return r; |
| 242 | } |
| 243 | |
| 244 | const struct ip_info *range_type(const ip_range *range) |
| 245 | { |
| 246 | const struct ip_info *start = address_type(&range->start); |
| 247 | const struct ip_info *end = address_type(&range->end); |
| 248 | if (!pexpect(start == end)({ _Bool assertion__ = start == end; if (!assertion__) { log_pexpect ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 248}, "%s", "start == end"); } assertion__; })) { |
| 249 | return NULL((void*)0); |
| 250 | } |
| 251 | return start; |
| 252 | } |
| 253 | |
| 254 | bool_Bool range_is_set(const ip_range *r) |
| 255 | { |
| 256 | return range_type(r) != NULL((void*)0); |
| 257 | } |
| 258 | |
| 259 | bool_Bool range_is_specified(const ip_range *r) |
| 260 | { |
| 261 | bool_Bool start = address_is_specified(&r->start); |
| 262 | bool_Bool end = address_is_specified(&r->end); |
| 263 | if (!pexpect(start == end)({ _Bool assertion__ = start == end; if (!assertion__) { log_pexpect ((where_t) { .func = __func__, .basename = "ip_range.c" , .line = 263}, "%s", "start == end"); } assertion__; })) { |
| 264 | return false0; |
| 265 | } |
| 266 | return start; |
| 267 | } |
| 268 | |
| 269 | bool_Bool range_size(ip_range *r, uint32_t *size) { |
| 270 | |
| 271 | bool_Bool truncated = false0; |
| 272 | uint32_t n = *size = 0; |
| 273 | |
| 274 | n = (ntohl_address(&r->end) - ntohl_address(&r->start)); |
| 275 | if (address_type(&r->start) == &ipv6_info) { |
| 276 | int prefix_len = ipv6_info.mask_cnt - iprange_bits(r->start, r->end); |
| 277 | if (prefix_len < IPV6_MIN_POOL_PREFIX_LEN96) { |
| 278 | truncated = true1; |
| 279 | uint32_t s = ntohl_address(&r->start); |
| 280 | n = UINT32_MAX(4294967295U) - s; |
| 281 | } |
| 282 | |
| 283 | if (n < UINT32_MAX(4294967295U)) |
| 284 | n++; |
| 285 | else |
| 286 | truncated = true1; |
| 287 | } else { |
| 288 | /* IPv4 */ |
| 289 | n++; |
| 290 | } |
| 291 | |
| 292 | *size = n; |
| 293 | return truncated; |
| 294 | } |