diff --git a/bin/ln/ln.c b/bin/ln/ln.c index 31fe3b35e25e..6300658effa1 100644 --- a/bin/ln/ln.c +++ b/bin/ln/ln.c @@ -1,348 +1,358 @@ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (c) 1987, 1993, 1994 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include static bool fflag; /* Unlink existing files. */ static bool Fflag; /* Remove empty directories also. */ static bool hflag; /* Check new name for symlink first. */ static bool iflag; /* Interactive mode. */ static bool Pflag; /* Create hard links to symlinks. */ static bool sflag; /* Symbolic, not hard, link. */ static bool vflag; /* Verbose output. */ static bool wflag; /* Warn if symlink target does not * exist, and -f is not enabled. */ static char linkch; static int linkit(const char *, const char *, bool); +static void link_usage(void) __dead2; static void usage(void) __dead2; int main(int argc, char *argv[]) { struct stat sb; - char *p, *targetdir; + char *targetdir; int ch, exitval; /* * Test for the special case where the utility is called as * "link", for which the functionality provided is greatly * simplified. */ - if ((p = strrchr(argv[0], '/')) == NULL) - p = argv[0]; - else - ++p; - if (strcmp(p, "link") == 0) { + if (strcmp(getprogname(), "link") == 0) { while (getopt(argc, argv, "") != -1) - usage(); + link_usage(); argc -= optind; argv += optind; if (argc != 2) - usage(); + link_usage(); + if (lstat(argv[1], &sb) == 0) + errc(1, EEXIST, "%s", argv[1]); + /* + * We could simply call link(2) here, but linkit() + * performs additional checks and gives better + * diagnostics. + */ exit(linkit(argv[0], argv[1], false)); } while ((ch = getopt(argc, argv, "FLPfhinsvw")) != -1) switch (ch) { case 'F': Fflag = true; break; case 'L': Pflag = false; break; case 'P': Pflag = true; break; case 'f': fflag = true; iflag = false; wflag = false; break; case 'h': case 'n': hflag = true; break; case 'i': iflag = true; fflag = false; break; case 's': sflag = true; break; case 'v': vflag = true; break; case 'w': wflag = true; break; case '?': default: usage(); } argv += optind; argc -= optind; linkch = sflag ? '-' : '='; if (!sflag) Fflag = false; if (Fflag && !iflag) { fflag = true; wflag = false; /* Implied when fflag is true */ } switch (argc) { case 0: usage(); /* NOTREACHED */ case 1: /* ln source */ exit(linkit(argv[0], ".", true)); case 2: /* ln source target */ exit(linkit(argv[0], argv[1], false)); default: ; } /* ln source1 source2 directory */ targetdir = argv[argc - 1]; if (hflag && lstat(targetdir, &sb) == 0 && S_ISLNK(sb.st_mode)) { /* * We were asked not to follow symlinks, but found one at * the target--simulate "not a directory" error */ errno = ENOTDIR; err(1, "%s", targetdir); } if (stat(targetdir, &sb)) err(1, "%s", targetdir); if (!S_ISDIR(sb.st_mode)) usage(); for (exitval = 0; *argv != targetdir; ++argv) exitval |= linkit(*argv, targetdir, true); exit(exitval); } /* * Two pathnames refer to the same directory entry if the directories match * and the final components' names match. */ static int samedirent(const char *path1, const char *path2) { const char *file1, *file2; char pathbuf[PATH_MAX]; struct stat sb1, sb2; if (strcmp(path1, path2) == 0) return 1; file1 = strrchr(path1, '/'); if (file1 != NULL) file1++; else file1 = path1; file2 = strrchr(path2, '/'); if (file2 != NULL) file2++; else file2 = path2; if (strcmp(file1, file2) != 0) return 0; if (file1 - path1 >= PATH_MAX || file2 - path2 >= PATH_MAX) return 0; if (file1 == path1) memcpy(pathbuf, ".", 2); else { memcpy(pathbuf, path1, file1 - path1); pathbuf[file1 - path1] = '\0'; } if (stat(pathbuf, &sb1) != 0) return 0; if (file2 == path2) memcpy(pathbuf, ".", 2); else { memcpy(pathbuf, path2, file2 - path2); pathbuf[file2 - path2] = '\0'; } if (stat(pathbuf, &sb2) != 0) return 0; return sb1.st_dev == sb2.st_dev && sb1.st_ino == sb2.st_ino; } static int linkit(const char *source, const char *target, bool isdir) { char path[PATH_MAX]; char wbuf[PATH_MAX]; char bbuf[PATH_MAX]; struct stat sb; const char *p; int ch, first; bool exists; if (!sflag) { /* If source doesn't exist, quit now. */ if ((Pflag ? lstat : stat)(source, &sb)) { warn("%s", source); return (1); } /* Only symbolic links to directories. */ if (S_ISDIR(sb.st_mode)) { errno = EISDIR; warn("%s", source); return (1); } } /* * If the target is a directory (and not a symlink if hflag), * append the source's name, unless Fflag is set. */ if (!Fflag && (isdir || (lstat(target, &sb) == 0 && S_ISDIR(sb.st_mode)) || (!hflag && stat(target, &sb) == 0 && S_ISDIR(sb.st_mode)))) { if (strlcpy(bbuf, source, sizeof(bbuf)) >= sizeof(bbuf) || (p = basename(bbuf)) == NULL || snprintf(path, sizeof(path), "%s/%s", target, p) >= (ssize_t)sizeof(path)) { errno = ENAMETOOLONG; warn("%s", source); return (1); } target = path; } /* * If the link source doesn't exist, and a symbolic link was * requested, and -w was specified, give a warning. */ if (sflag && wflag) { if (*source == '/') { /* Absolute link source. */ if (stat(source, &sb) != 0) warn("warning: %s inaccessible", source); } else { /* * Relative symlink source. Try to construct the * absolute path of the source, by appending `source' * to the parent directory of the target. */ strlcpy(bbuf, target, sizeof(bbuf)); p = dirname(bbuf); if (p != NULL) { (void)snprintf(wbuf, sizeof(wbuf), "%s/%s", p, source); if (stat(wbuf, &sb) != 0) warn("warning: %s", source); } } } /* * If the file exists, first check it is not the same directory entry. */ exists = lstat(target, &sb) == 0; if (exists) { if (!sflag && samedirent(source, target)) { warnx("%s and %s are the same directory entry", source, target); return (1); } } /* * Then unlink it forcibly if -f was specified * and interactively if -i was specified. */ if (fflag && exists) { if (Fflag && S_ISDIR(sb.st_mode)) { if (rmdir(target)) { warn("%s", target); return (1); } } else if (unlink(target)) { warn("%s", target); return (1); } } else if (iflag && exists) { fflush(stdout); fprintf(stderr, "replace %s? ", target); first = ch = getchar(); while(ch != '\n' && ch != EOF) ch = getchar(); if (first != 'y' && first != 'Y') { fprintf(stderr, "not replaced\n"); return (1); } if (Fflag && S_ISDIR(sb.st_mode)) { if (rmdir(target)) { warn("%s", target); return (1); } } else if (unlink(target)) { warn("%s", target); return (1); } } /* Attempt the link. */ if (sflag ? symlink(source, target) : linkat(AT_FDCWD, source, AT_FDCWD, target, Pflag ? 0 : AT_SYMLINK_FOLLOW)) { warn("%s", target); return (1); } if (vflag) (void)printf("%s %c> %s\n", target, linkch, source); return (0); } +static void +link_usage(void) +{ + (void)fprintf(stderr, "usage: link source_file target_file\n"); + exit(1); +} + static void usage(void) { - (void)fprintf(stderr, "%s\n%s\n%s\n", + (void)fprintf(stderr, "%s\n%s\n", "usage: ln [-s [-F] | -L | -P] [-f | -i] [-hnv] source_file [target_file]", - " ln [-s [-F] | -L | -P] [-f | -i] [-hnv] source_file ... target_dir", - " link source_file target_file"); + " ln [-s [-F] | -L | -P] [-f | -i] [-hnv] source_file ... target_dir"); exit(1); } diff --git a/bin/ln/tests/ln_test.sh b/bin/ln/tests/ln_test.sh index 8e5dcf81e61f..82bc556842d8 100644 --- a/bin/ln/tests/ln_test.sh +++ b/bin/ln/tests/ln_test.sh @@ -1,232 +1,291 @@ # # SPDX-License-Identifier: BSD-2-Clause # # Copyright 2017 Shivansh Rai # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions # are met: # 1. Redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer. # 2. Redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution. # # THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND # ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE # IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE # ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE # FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL # DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS # OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) # HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY # OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF # SUCH DAMAGE. # atf_check_same_file() { atf_check_equal "$(stat -f %d,%i "$1")" "$(stat -f %d,%i "$2")" } atf_check_symlink_to() { atf_check -o inline:"$1\n" readlink "$2" } atf_test_case L_flag L_flag_head() { atf_set "descr" "Verify that when creating a hard link to a " \ "symbolic link, '-L' option creates a hard" \ "link to the target of the symbolic link" } L_flag_body() { atf_check touch A atf_check ln -s A B atf_check ln -L B C atf_check_same_file A C atf_check_symlink_to A B } atf_test_case P_flag P_flag_head() { atf_set "descr" "Verify that when creating a hard link to a " \ "symbolic link, '-P' option creates a hard " \ "link to the symbolic link itself" } P_flag_body() { atf_check touch A atf_check ln -s A B atf_check ln -P B C atf_check_same_file B C } atf_test_case f_flag f_flag_head() { atf_set "descr" "Verify that if the target file already exists, " \ "'-f' option unlinks it so that link may occur" } f_flag_body() { atf_check touch A B atf_check ln -f A B atf_check_same_file A B } atf_test_case target_exists_hard target_exists_hard_head() { atf_set "descr" "Verify whether creating a hard link fails if the " \ "target file already exists" } target_exists_hard_body() { atf_check touch A B atf_check -s exit:1 -e inline:'ln: B: File exists\n' \ - ln A B + ln A B } atf_test_case target_exists_symbolic target_exists_symbolic_head() { atf_set "descr" "Verify whether creating a symbolic link fails if " \ "the target file already exists" } target_exists_symbolic_body() { atf_check touch A B atf_check -s exit:1 -e inline:'ln: B: File exists\n' \ - ln -s A B + ln -s A B } atf_test_case shf_flag_dir shf_flag_dir_head() { atf_set "descr" "Verify that if the target directory is a symbolic " \ "link, '-shf' option prevents following the link" } shf_flag_dir_body() { atf_check mkdir -m 0777 A B atf_check ln -s A C atf_check ln -shf B C atf_check test -L C atf_check -o inline:'B\n' readlink C } atf_test_case snf_flag_dir snf_flag_dir_head() { atf_set "descr" "Verify that if the target directory is a symbolic " \ "link, '-snf' option prevents following the link" } snf_flag_dir_body() { atf_check mkdir -m 0777 A B atf_check ln -s A C atf_check ln -snf B C atf_check_symlink_to B C } atf_test_case sF_flag sF_flag_head() { atf_set "descr" "Verify that if the target file already exists " \ "and is a directory, then '-sF' option removes " \ "it so that the link may occur" } sF_flag_body() { atf_check mkdir A B atf_check ln -sF A B atf_check_symlink_to A B } atf_test_case sf_flag sf_flag_head() { atf_set "descr" "Verify that if the target file already exists, " \ "'-sf' option unlinks it and creates a symbolic link " \ "to the source file" } sf_flag_body() { atf_check touch A B atf_check ln -sf A B atf_check_symlink_to A B } atf_test_case sfF_flag sfF_flag_head() { atf_set "descr" "Verify that if the target file already exists " \ "and is a symlink, then '-sfF' option removes " \ "it so that the link may occur" } sfF_flag_body() { atf_check mkdir A B C atf_check ln -sF A C atf_check_symlink_to A C atf_check ln -sfF B C atf_check_symlink_to B C } atf_test_case s_flag s_flag_head() { atf_set "descr" "Verify that '-s' option creates a symbolic link" } s_flag_body() { atf_check touch A atf_check ln -s A B atf_check_symlink_to A B } atf_test_case s_flag_broken s_flag_broken_head() { atf_set "descr" "Verify that if the source file does not exists, '-s' " \ "option creates a broken symbolic link to the source file" } s_flag_broken_body() { atf_check ln -s A B atf_check_symlink_to A B } atf_test_case sw_flag sw_flag_head() { atf_set "descr" "Verify that '-sw' option produces a warning if the " \ "source of a symbolic link does not currently exist" } sw_flag_body() { atf_check -s exit:0 -e inline:'ln: warning: A: No such file or directory\n' \ - ln -sw A B + ln -sw A B atf_check_symlink_to A B } +atf_test_case link_argc +link_argc_head() { + atf_set "descr" "Verify that link(1) requires exactly two arguments" +} +link_argc_body() { + atf_check -s exit:1 -e match:"usage: link" \ + link foo + atf_check -s exit:1 -e match:"No such file" \ + link foo bar + atf_check -s exit:1 -e match:"No such file" \ + link -- foo bar + atf_check -s exit:1 -e match:"usage: link" \ + link foo bar baz +} + +atf_test_case link_basic +link_basic_head() { + atf_set "descr" "Verify that link(1) creates a link" +} +link_basic_body() { + touch foo + atf_check link foo bar + atf_check_same_file foo bar + rm bar + ln -s foo bar + atf_check link bar baz + atf_check_same_file foo baz +} + +atf_test_case link_eexist +link_eexist_head() { + atf_set "descr" "Verify that link(1) fails if the target exists" +} +link_eexist_body() { + touch foo bar + atf_check -s exit:1 -e match:"bar.*exists" \ + link foo bar + ln -s non-existent baz + atf_check -s exit:1 -e match:"baz.*exists" \ + link foo baz +} + +atf_test_case link_eisdir +link_eisdir_head() { + atf_set "descr" "Verify that link(1) fails if the source is a directory" +} +link_eisdir_body() { + mkdir foo + atf_check -s exit:1 -e match:"foo.*directory" \ + link foo bar + ln -s foo bar + atf_check -s exit:1 -e match:"bar.*directory" \ + link bar baz +} + atf_init_test_cases() { atf_add_test_case L_flag atf_add_test_case P_flag atf_add_test_case f_flag atf_add_test_case target_exists_hard atf_add_test_case target_exists_symbolic atf_add_test_case shf_flag_dir atf_add_test_case snf_flag_dir atf_add_test_case sF_flag atf_add_test_case sf_flag atf_add_test_case sfF_flag atf_add_test_case s_flag atf_add_test_case s_flag_broken atf_add_test_case sw_flag + atf_add_test_case link_argc + atf_add_test_case link_basic + atf_add_test_case link_eexist + atf_add_test_case link_eisdir }