| 1 | /* Simple subrs. |
| 2 | Copyright (C) 2019-2020 Free Software Foundation, Inc. |
| 3 | |
| 4 | This file is part of libctf. |
| 5 | |
| 6 | libctf is free software; you can redistribute it and/or modify it under |
| 7 | the terms of the GNU General Public License as published by the Free |
| 8 | Software Foundation; either version 3, or (at your option) any later |
| 9 | version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, but |
| 12 | WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| 14 | See the GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; see the file COPYING. If not see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <ctf-impl.h> |
| 21 | #ifdef HAVE_MMAP |
| 22 | #include <sys/mman.h> |
| 23 | #endif |
| 24 | #include <sys/types.h> |
| 25 | #include <stdarg.h> |
| 26 | #include <string.h> |
| 27 | #include <unistd.h> |
| 28 | |
| 29 | int _libctf_version = CTF_VERSION; /* Library client version. */ |
| 30 | int _libctf_debug = 0; /* Debugging messages enabled. */ |
| 31 | |
| 32 | /* Private, read-only mmap from a file, with fallback to copying. |
| 33 | |
| 34 | No handling of page-offset issues at all: the caller must allow for that. */ |
| 35 | |
| 36 | _libctf_malloc_ void * |
| 37 | ctf_mmap (size_t length, size_t offset, int fd) |
| 38 | { |
| 39 | void *data; |
| 40 | |
| 41 | #ifdef HAVE_MMAP |
| 42 | data = mmap (NULL, length, PROT_READ, MAP_PRIVATE, fd, offset); |
| 43 | if (data == MAP_FAILED) |
| 44 | data = NULL; |
| 45 | #else |
| 46 | if ((data = malloc (length)) != NULL) |
| 47 | { |
| 48 | if (ctf_pread (fd, data, length, offset) <= 0) |
| 49 | { |
| 50 | free (data); |
| 51 | data = NULL; |
| 52 | } |
| 53 | } |
| 54 | #endif |
| 55 | return data; |
| 56 | } |
| 57 | |
| 58 | void |
| 59 | ctf_munmap (void *buf, size_t length _libctf_unused_) |
| 60 | { |
| 61 | #ifdef HAVE_MMAP |
| 62 | (void) munmap (buf, length); |
| 63 | #else |
| 64 | free (buf); |
| 65 | #endif |
| 66 | } |
| 67 | |
| 68 | ssize_t |
| 69 | ctf_pread (int fd, void *buf, ssize_t count, off_t offset) |
| 70 | { |
| 71 | ssize_t len; |
| 72 | size_t acc = 0; |
| 73 | char *data = (char *) buf; |
| 74 | |
| 75 | #ifdef HAVE_PREAD |
| 76 | while (count > 0) |
| 77 | { |
| 78 | errno = 0; |
| 79 | if (((len = pread (fd, data, count, offset)) < 0) && |
| 80 | errno != EINTR) |
| 81 | return len; |
| 82 | if (errno == EINTR) |
| 83 | continue; |
| 84 | |
| 85 | acc += len; |
| 86 | if (len == 0) /* EOF. */ |
| 87 | return acc; |
| 88 | |
| 89 | count -= len; |
| 90 | offset += len; |
| 91 | data += len; |
| 92 | } |
| 93 | return acc; |
| 94 | #else |
| 95 | off_t orig_off; |
| 96 | |
| 97 | if ((orig_off = lseek (fd, 0, SEEK_CUR)) < 0) |
| 98 | return -1; |
| 99 | if ((lseek (fd, offset, SEEK_SET)) < 0) |
| 100 | return -1; |
| 101 | |
| 102 | while (count > 0) |
| 103 | { |
| 104 | errno = 0; |
| 105 | if (((len = read (fd, data, count)) < 0) && |
| 106 | errno != EINTR) |
| 107 | return len; |
| 108 | if (errno == EINTR) |
| 109 | continue; |
| 110 | |
| 111 | acc += len; |
| 112 | if (len == 0) /* EOF. */ |
| 113 | break; |
| 114 | |
| 115 | count -= len; |
| 116 | data += len; |
| 117 | } |
| 118 | if ((lseek (fd, orig_off, SEEK_SET)) < 0) |
| 119 | return -1; /* offset is smashed. */ |
| 120 | #endif |
| 121 | |
| 122 | return acc; |
| 123 | } |
| 124 | |
| 125 | const char * |
| 126 | ctf_strerror (int err) |
| 127 | { |
| 128 | return (const char *) (strerror (err)); |
| 129 | } |
| 130 | |
| 131 | /* Set the CTF library client version to the specified version. If version is |
| 132 | zero, we just return the default library version number. */ |
| 133 | int |
| 134 | ctf_version (int version) |
| 135 | { |
| 136 | if (version < 0) |
| 137 | { |
| 138 | errno = EINVAL; |
| 139 | return -1; |
| 140 | } |
| 141 | |
| 142 | if (version > 0) |
| 143 | { |
| 144 | /* Dynamic version switching is not presently supported. */ |
| 145 | if (version != CTF_VERSION) |
| 146 | { |
| 147 | errno = ENOTSUP; |
| 148 | return -1; |
| 149 | } |
| 150 | ctf_dprintf ("ctf_version: client using version %d\n", version); |
| 151 | _libctf_version = version; |
| 152 | } |
| 153 | |
| 154 | return _libctf_version; |
| 155 | } |
| 156 | |
| 157 | void |
| 158 | libctf_init_debug (void) |
| 159 | { |
| 160 | static int inited; |
| 161 | if (!inited) |
| 162 | { |
| 163 | _libctf_debug = getenv ("LIBCTF_DEBUG") != NULL; |
| 164 | inited = 1; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | void ctf_setdebug (int debug) |
| 169 | { |
| 170 | /* Ensure that libctf_init_debug() has been called, so that we don't get our |
| 171 | debugging-on-or-off smashed by the next call. */ |
| 172 | |
| 173 | libctf_init_debug(); |
| 174 | _libctf_debug = debug; |
| 175 | ctf_dprintf ("CTF debugging set to %i\n", debug); |
| 176 | } |
| 177 | |
| 178 | int ctf_getdebug (void) |
| 179 | { |
| 180 | return _libctf_debug; |
| 181 | } |
| 182 | |
| 183 | _libctf_printflike_ (1, 2) |
| 184 | void ctf_dprintf (const char *format, ...) |
| 185 | { |
| 186 | if (_libctf_debug) |
| 187 | { |
| 188 | va_list alist; |
| 189 | |
| 190 | va_start (alist, format); |
| 191 | fflush (stdout); |
| 192 | (void) fputs ("libctf DEBUG: ", stderr); |
| 193 | (void) vfprintf (stderr, format, alist); |
| 194 | va_end (alist); |
| 195 | } |
| 196 | } |