* zic.c: Use angle brackets for <sys/stat.h>. (dolink): Don't try to link from a directory, as this can cause trouble on some systems when superuser. (dolink, itsdir): Rewrite to avoid use of 'access', which is problematic when setuid. (itsdir): If S_ISDIR is defined, use plain 'stat' and S_ISDIR; that's more reliable. Return -1 if trouble; all callers changed. (mkdirs): Simplify by using mkdir-itsdir rather than itsdir-mkdir-itsdir. Don't assume strerror preserves errno. --- zic.c | 71 +++++++++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 41 insertions(+), 30 deletions(-) diff --git a/zic.c b/zic.c index 9c22e7a..f18dba7 100644 --- a/zic.c +++ b/zic.c @@ -23,7 +23,7 @@ typedef int_fast64_t zic_t; #endif /* !defined ZIC_MAX_ABBR_LEN_WO_WARN */ #if HAVE_SYS_STAT_H -#include "sys/stat.h" +#include <sys/stat.h> #endif #ifdef S_IRUSR #define MKDIR_UMASK (S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) @@ -665,6 +665,7 @@ dolink(const char *const fromfield, const char *const tofield) { register char * fromname; register char * toname; + register int fromisdir; namecheck(tofield); if (fromfield[0] == '/') @@ -685,10 +686,16 @@ dolink(const char *const fromfield, const char *const tofield) ** We get to be careful here since ** there's a fair chance of root running us. */ - if (!itsdir(toname)) + fromisdir = itsdir(fromname); + if (fromisdir) { + int err = fromisdir < 0 ? errno : EPERM; + fprintf(stderr, _("%s: link from %s failed: %s"), + progname, fromname, strerror(err)); + exit(EXIT_FAILURE); + } + if (itsdir(toname) <= 0) (void) remove(toname); - if (link(fromname, toname) != 0 - && access(fromname, F_OK) == 0 && !itsdir(fromname)) { + if (link(fromname, toname) != 0) { int result; if (mkdirs(toname) != 0) @@ -793,17 +800,24 @@ static const zic_t max_time = -1 - ((zic_t) -1 << (TIME_T_BITS_IN_FILE - 1)); static const zic_t big_bang_time = BIG_BANG; +/* Return 1 if NAME is a directory, 0 if it's something else, -1 if trouble. */ static int itsdir(const char *const name) { - register char * myname; - register int accres; - - myname = ecpyalloc(name); - myname = ecatalloc(myname, "/."); - accres = access(myname, F_OK); - free(myname); - return accres == 0; + struct stat st; + int res = stat(name, &st); + if (res != 0) + return res; +#ifdef S_ISDIR + return S_ISDIR(st.st_mode) != 0; +#else + { + char *nameslashdot = ecatalloc(ecpyalloc(name), "/."); + res = stat(nameslashdot, &st); + free(nameslashdot); + return res == 0; + } +#endif } /* @@ -1620,7 +1634,7 @@ writezone(const char *const name, const char *const string, char version) /* ** Remove old file, if any, to snap links. */ - if (!itsdir(fullname) && remove(fullname) != 0 && errno != ENOENT) { + if (itsdir(fullname) <= 0 && remove(fullname) != 0 && errno != ENOENT) { const char *e = strerror(errno); (void) fprintf(stderr, _("%s: Can't remove %s: %s\n"), @@ -2891,23 +2905,20 @@ mkdirs(char *argname) continue; } #endif - if (!itsdir(name)) { - /* - ** It doesn't seem to exist, so we try to create it. - ** Creation may fail because of the directory being - ** created by some other multiprocessor, so we get - ** to do extra checking. - */ - if (mkdir(name, MKDIR_UMASK) != 0) { - const char *e = strerror(errno); - - if (errno != EEXIST || !itsdir(name)) { - (void) fprintf(stderr, -_("%s: Can't create directory %s: %s\n"), - progname, name, e); - free(name); - return -1; - } + /* + ** Try to create it. It's OK if creation fails because + ** the directory already exists, perhaps because some + ** other process just created it. + */ + if (mkdir(name, MKDIR_UMASK) != 0) { + int err = errno; + if (itsdir(name) <= 0) { + (void) fprintf(stderr, + _("%s: Can't create directory" + " %s: %s\n"), + progname, name, strerror(err)); + free(name); + return -1; } } *cp = '/'; -- 1.9.1