| 1 | /* Skip over a (potentially compressed) domain name in wire format. |
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| 2 | * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") |
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| 3 | * Copyright (c) 1996,1999 by Internet Software Consortium. |
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| 4 | * |
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| 5 | * Permission to use, copy, modify, and distribute this software for any |
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| 6 | * purpose with or without fee is hereby granted, provided that the above |
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| 7 | * copyright notice and this permission notice appear in all copies. |
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| 8 | * |
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| 9 | * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES |
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| 10 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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| 11 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR |
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| 12 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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| 13 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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| 14 | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT |
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| 15 | * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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| 16 | */ |
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| 17 | |
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| 18 | #include <arpa/nameser.h> |
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| 19 | #include <errno.h> |
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| 20 | #include <shlib-compat.h> |
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| 21 | |
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| 22 | /* Advances *PTRPTR to skip over the compressed name it points at. |
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| 23 | Returns 0 on success, -1 (with errno set) on failure. */ |
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| 24 | int |
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| 25 | ___ns_name_skip (const unsigned char **ptrptr, const unsigned char *eom) |
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| 26 | { |
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| 27 | const unsigned char *cp; |
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| 28 | unsigned int n; |
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| 29 | |
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| 30 | cp = *ptrptr; |
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| 31 | while (cp < eom) |
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| 32 | { |
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| 33 | n = *cp++; |
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| 34 | if (n == 0) |
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| 35 | { |
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| 36 | /* End of domain name without indirection. */ |
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| 37 | *ptrptr = cp; |
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| 38 | return 0; |
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| 39 | } |
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| 40 | |
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| 41 | /* Check for indirection. */ |
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| 42 | switch (n & NS_CMPRSFLGS) |
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| 43 | { |
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| 44 | case 0: /* Normal case, n == len. */ |
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| 45 | if (eom - cp < n) |
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| 46 | goto malformed; |
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| 47 | cp += n; |
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| 48 | break; |
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| 49 | case NS_CMPRSFLGS: /* Indirection. */ |
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| 50 | if (cp == eom) |
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| 51 | /* No room for second indirection byte. */ |
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| 52 | goto malformed; |
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| 53 | *ptrptr = cp + 1; |
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| 54 | return 0; |
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| 55 | default: /* Illegal type. */ |
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| 56 | goto malformed; |
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| 57 | } |
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| 58 | } |
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| 59 | |
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| 60 | malformed: |
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| 61 | __set_errno (EMSGSIZE); |
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| 62 | return -1; |
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| 63 | } |
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| 64 | versioned_symbol (libc, ___ns_name_skip, ns_name_skip, GLIBC_2_34); |
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| 65 | versioned_symbol (libc, ___ns_name_skip, __ns_name_skip, GLIBC_PRIVATE); |
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| 66 | libc_hidden_ver (___ns_name_skip, __ns_name_skip) |
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| 67 | |
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| 68 | #if OTHER_SHLIB_COMPAT (libresolv, GLIBC_2_9, GLIBC_2_34) |
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| 69 | compat_symbol (libresolv, ___ns_name_skip, ns_name_skip, GLIBC_2_9); |
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| 70 | #endif |
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| 71 | |
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