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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:30:08 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-08-07 13:30:08 +0000 |
commit | 44cf9c6d2d274eac37502e835155f7e985f1b8e6 (patch) | |
tree | 9576ba968924c5b9a55ba9e14f4f26184c62c7d4 /src/realpath/main.c | |
parent | Adding upstream version 1.22.6. (diff) | |
download | dpkg-44cf9c6d2d274eac37502e835155f7e985f1b8e6.tar.xz dpkg-44cf9c6d2d274eac37502e835155f7e985f1b8e6.zip |
Adding upstream version 1.22.7.upstream/1.22.7
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/realpath/main.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/src/realpath/main.c b/src/realpath/main.c new file mode 100644 index 0000000..bfa2aa2 --- /dev/null +++ b/src/realpath/main.c @@ -0,0 +1,247 @@ +/* + * dpkg-realpath - print the resolved pathname with DPKG_ROOT support + * + * Copyright © 2020 Helmut Grohne <helmut@subdivi.de> + * Copyright © 2020-2024 Guillem Jover <guillem@debian.org> + * + * This is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <compat.h> + +#include <sys/types.h> +#include <sys/stat.h> + +#include <errno.h> +#ifdef HAVE_LOCALE_H +#include <locale.h> +#endif +#include <string.h> +#include <unistd.h> +#include <stdint.h> +#include <stdlib.h> +#include <stdio.h> + +#include <dpkg/i18n.h> +#include <dpkg/dpkg.h> +#include <dpkg/dpkg-db.h> +#include <dpkg/debug.h> +#include <dpkg/string.h> +#include <dpkg/db-fsys.h> +#include <dpkg/options.h> + +static const char printforhelp[] = N_( +"Use --help for help about this utility."); + +static void DPKG_ATTR_NORET +printversion(const struct cmdinfo *cip, const char *value) +{ + printf(_("Debian %s version %s.\n"), dpkg_get_progname(), + PACKAGE_RELEASE); + + printf(_( +"This is free software; see the GNU General Public License version 2 or\n" +"later for copying conditions. There is NO warranty.\n")); + + m_output(stdout, _("<standard output>")); + + exit(0); +} + +static void DPKG_ATTR_NORET +usage(const struct cmdinfo *cip, const char *value) +{ + printf(_( +"Usage: %s [<option>...] <pathname>\n" +"\n"), dpkg_get_progname()); + + printf(_( +"Options:\n" +" -z, --zero end output line with NUL, not newline.\n" +" --instdir <directory> set the root directory.\n" +" --root <directory> set the root directory.\n" +" --version show the version.\n" +" --help show this help message.\n" +"\n")); + + m_output(stdout, _("<standard output>")); + + exit(0); +} + +static int opt_eol = '\n'; + +static char * +realpath_relative_to(const char *pathname, const char *rootdir) +{ + struct varbuf root = VARBUF_INIT; + struct varbuf src = VARBUF_INIT; + struct varbuf dst = VARBUF_INIT; + struct varbuf slink = VARBUF_INIT; + struct varbuf result = VARBUF_INIT; + struct varbuf prefix = VARBUF_INIT; + int loop = 0; + + varbuf_init(&root, 32); + varbuf_init(&src, 32); + varbuf_init(&dst, 32); + varbuf_init(&result, 32); + + varbuf_set_str(&root, rootdir); + varbuf_set_str(&src, pathname); + varbuf_set_str(&result, rootdir); + + /* Check whether the path is relative, make it absolute otherwise. */ + if (src.buf[0] != '/') { + struct varbuf abs_src = VARBUF_INIT; + + file_getcwd(&abs_src); + varbuf_add_char(&abs_src, '/'); + varbuf_add_varbuf(&abs_src, &src); + + varbuf_set_varbuf(&src, &abs_src); + varbuf_destroy(&abs_src); + + varbuf_trim_varbuf_prefix(&src, &root); + } + + /* Remove prefixed slashes. */ + varbuf_trim_char_prefix(&src, '/'); + + while (src.used) { + struct stat st; + const char *slash; + + /* Get the first directory component. */ + varbuf_set_varbuf(&prefix, &src); + slash = strchrnul(prefix.buf, '/'); + varbuf_trunc(&prefix, slash - prefix.buf); + + /* Remove the first directory component from src. */ + varbuf_trim_varbuf_prefix(&src, &prefix); + + /* Remove prefixed slashes. */ + varbuf_trim_char_prefix(&src, '/'); + + varbuf_set_varbuf(&slink, &result); + varbuf_add_char(&slink, '/'); + varbuf_add_varbuf(&slink, &prefix); + + /* Resolve the first directory component. */ + if (strcmp(prefix.buf, ".") == 0) { + /* Ignore, stay at the same directory. */ + } else if (strcmp(prefix.buf, "..") == 0) { + /* Go up one directory. */ + slash = strrchr(result.buf, '/'); + if (slash != NULL) + varbuf_trunc(&result, slash - result.buf); + + if (root.used && !varbuf_has_prefix(&result, &root)) + varbuf_set_varbuf(&result, &root); + } else if (lstat(slink.buf, &st) == 0 && S_ISLNK(st.st_mode)) { + ssize_t linksize; + + loop++; + if (loop > 25) + ohshit(_("too many levels of symbolic links")); + + /* Resolve the symlink within result. */ + linksize = file_readlink(slink.buf, &dst, st.st_size); + if (linksize < 0) + ohshite(_("cannot read link '%s'"), slink.buf); + else if ((off_t)linksize != st.st_size) + ohshit(_("symbolic link '%s' size has changed from %jd to %zd"), + slink.buf, (intmax_t)st.st_size, linksize); + + if (dst.buf[0] == '/') { + /* Absolute pathname, reset result back to + * root. */ + varbuf_set_varbuf(&result, &root); + + if (src.used) { + varbuf_add_char(&dst, '/'); + varbuf_add_varbuf(&dst, &src); + } + varbuf_set_varbuf(&src, &dst); + + /* Remove prefixed slashes. */ + varbuf_trim_char_prefix(&src, '/'); + } else { + /* Relative pathname. */ + if (src.used) { + varbuf_add_char(&dst, '/'); + varbuf_add_varbuf(&dst, &src); + } + varbuf_set_varbuf(&src, &dst); + } + } else { + /* Otherwise append the prefix. */ + varbuf_add_char(&result, '/'); + varbuf_add_varbuf(&result, &prefix); + } + } + + /* We are done, return the resolved pathname, w/o root. */ + varbuf_trim_varbuf_prefix(&result, &root); + + varbuf_destroy(&root); + varbuf_destroy(&src); + varbuf_destroy(&dst); + varbuf_destroy(&slink); + varbuf_destroy(&prefix); + + return varbuf_detach(&result); +} + +static const struct cmdinfo cmdinfos[] = { + { "zero", 'z', 0, &opt_eol, NULL, NULL, '\0' }, + { "instdir", 0, 1, NULL, NULL, set_instdir, 0 }, + { "root", 0, 1, NULL, NULL, set_instdir, 0 }, + { "version", 0, 0, NULL, NULL, printversion }, + { "help", '?', 0, NULL, NULL, usage }, + { NULL, 0 } +}; + +int +main(int argc, const char *const *argv) +{ + const char *instdir; + const char *pathname; + char *real_pathname; + + dpkg_locales_init(PACKAGE); + dpkg_program_init("dpkg-realpath"); + dpkg_options_parse(&argv, cmdinfos, printforhelp); + + debug(dbg_general, "root=%s admindir=%s", dpkg_fsys_get_dir(), dpkg_db_get_dir()); + + pathname = argv[0]; + if (str_is_unset(pathname)) + badusage(_("need a pathname argument")); + + instdir = dpkg_fsys_get_dir(); + if (strlen(instdir) && strncmp(pathname, instdir, strlen(instdir)) == 0) + badusage(_("link '%s' includes root prefix '%s'"), + pathname, instdir); + + real_pathname = realpath_relative_to(pathname, instdir); + printf("%s%c", real_pathname, opt_eol); + free(real_pathname); + + dpkg_program_done(); + dpkg_locales_done(); + + return 0; +} |