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Diffstat (limited to '')
| -rw-r--r-- | lib/fileutils.c | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/lib/fileutils.c b/lib/fileutils.c new file mode 100644 index 0000000..003f890 --- /dev/null +++ b/lib/fileutils.c @@ -0,0 +1,248 @@ +/* + * This code is in the public domain; do with it what you wish. + * + * Copyright (C) 2012 Sami Kerola <kerolasa@iki.fi> + * Copyright (C) 2012-2020 Karel Zak <kzak@redhat.com> + */ +#include <stdio.h> +#include <stdlib.h> +#include <sys/stat.h> +#include <unistd.h> +#include <sys/time.h> +#include <sys/resource.h> + +#include "c.h" +#include "fileutils.h" +#include "pathnames.h" + +int mkstemp_cloexec(char *template) +{ +#ifdef HAVE_MKOSTEMP + return mkostemp(template, O_RDWR|O_CREAT|O_EXCL|O_CLOEXEC); +#else + int fd, old_flags, errno_save; + + fd = mkstemp(template); + if (fd < 0) + return fd; + + old_flags = fcntl(fd, F_GETFD, 0); + if (old_flags < 0) + goto unwind; + if (fcntl(fd, F_SETFD, old_flags | O_CLOEXEC) < 0) + goto unwind; + + return fd; + +unwind: + errno_save = errno; + unlink(template); + close(fd); + errno = errno_save; + + return -1; +#endif +} + +/* Create open temporary file in safe way. Please notice that the + * file permissions are -rw------- by default. */ +int xmkstemp(char **tmpname, const char *dir, const char *prefix) +{ + char *localtmp; + const char *tmpenv; + mode_t old_mode; + int fd, rc; + + /* Some use cases must be capable of being moved atomically + * with rename(2), which is the reason why dir is here. */ + tmpenv = dir ? dir : getenv("TMPDIR"); + if (!tmpenv) + tmpenv = _PATH_TMP; + + rc = asprintf(&localtmp, "%s/%s.XXXXXX", tmpenv, prefix); + if (rc < 0) + return -1; + + old_mode = umask(077); + fd = mkstemp_cloexec(localtmp); + umask(old_mode); + if (fd == -1) { + free(localtmp); + localtmp = NULL; + } + *tmpname = localtmp; + return fd; +} + +int dup_fd_cloexec(int oldfd, int lowfd) +{ + int fd, flags, errno_save; + +#ifdef F_DUPFD_CLOEXEC + fd = fcntl(oldfd, F_DUPFD_CLOEXEC, lowfd); + if (fd >= 0) + return fd; +#endif + + fd = dup(oldfd); + if (fd < 0) + return fd; + + flags = fcntl(fd, F_GETFD); + if (flags < 0) + goto unwind; + if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) < 0) + goto unwind; + + return fd; + +unwind: + errno_save = errno; + close(fd); + errno = errno_save; + + return -1; +} + +/* + * portable getdtablesize() + */ +int get_fd_tabsize(void) +{ + int m; + +#if defined(HAVE_GETDTABLESIZE) + m = getdtablesize(); +#elif defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE) + struct rlimit rl; + + getrlimit(RLIMIT_NOFILE, &rl); + m = rl.rlim_cur; +#elif defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX) + m = sysconf(_SC_OPEN_MAX); +#else + m = OPEN_MAX; +#endif + return m; +} + +static inline int in_set(int x, const int set[], size_t setsz) +{ + size_t i; + + for (i = 0; i < setsz; i++) { + if (set[i] == x) + return 1; + } + return 0; +} + +void close_all_fds(const int exclude[], size_t exsz) +{ + struct dirent *d; + DIR *dir; + + dir = opendir(_PATH_PROC_FDDIR); + if (dir) { + while ((d = xreaddir(dir))) { + char *end; + int fd; + + errno = 0; + fd = strtol(d->d_name, &end, 10); + + if (errno || end == d->d_name || !end || *end) + continue; + if (dirfd(dir) == fd) + continue; + if (in_set(fd, exclude, exsz)) + continue; + close(fd); + } + closedir(dir); + } else { + int fd, tbsz = get_fd_tabsize(); + + for (fd = 0; fd < tbsz; fd++) { + if (!in_set(fd, exclude, exsz)) + close(fd); + } + } +} + +#ifdef TEST_PROGRAM_FILEUTILS +int main(int argc, char *argv[]) +{ + if (argc < 2) + errx(EXIT_FAILURE, "Usage %s --{mkstemp,close-fds}", argv[0]); + + if (strcmp(argv[1], "--mkstemp") == 0) { + FILE *f; + char *tmpname; + f = xfmkstemp(&tmpname, NULL, "test"); + unlink(tmpname); + free(tmpname); + fclose(f); + + } else if (strcmp(argv[1], "--close-fds") == 0) { + static const int wanted_fds[] = { + STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO + }; + + ignore_result( dup(STDIN_FILENO) ); + ignore_result( dup(STDIN_FILENO) ); + ignore_result( dup(STDIN_FILENO) ); + + close_all_fds(wanted_fds, ARRAY_SIZE(wanted_fds)); + } + return EXIT_SUCCESS; +} +#endif + + +int mkdir_p(const char *path, mode_t mode) +{ + char *p, *dir; + int rc = 0; + + if (!path || !*path) + return -EINVAL; + + dir = p = strdup(path); + if (!dir) + return -ENOMEM; + + if (*p == '/') + p++; + + while (p && *p) { + char *e = strchr(p, '/'); + if (e) + *e = '\0'; + if (*p) { + rc = mkdir(dir, mode); + if (rc && errno != EEXIST) + break; + rc = 0; + } + if (!e) + break; + *e = '/'; + p = e + 1; + } + + free(dir); + return rc; +} + +/* returns basename and keeps dirname in the @path, if @path is "/" (root) + * then returns empty string */ +char *stripoff_last_component(char *path) +{ + char *p = path ? strrchr(path, '/') : NULL; + + if (!p) + return NULL; + *p = '\0'; + return p + 1; +} |