Index: head/lib/libutil/pidfile.c =================================================================== --- head/lib/libutil/pidfile.c (revision 362633) +++ head/lib/libutil/pidfile.c (revision 362634) @@ -1,332 +1,332 @@ /*- * SPDX-License-Identifier: BSD-2-Clause-FreeBSD * * Copyright (c) 2005 Pawel Jakub Dawidek * 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 AUTHORS 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 AUTHORS 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 __FBSDID("$FreeBSD$"); #include #include #include #include #include #include #include #include #include #include #include #include #include #include struct pidfh { int pf_dirfd; int pf_fd; char pf_dir[MAXPATHLEN + 1]; char pf_filename[MAXPATHLEN + 1]; dev_t pf_dev; ino_t pf_ino; }; static int _pidfile_remove(struct pidfh *pfh, int freeit); static int pidfile_verify(const struct pidfh *pfh) { struct stat sb; if (pfh == NULL || pfh->pf_fd == -1) return (EDOOFUS); /* * Check remembered descriptor. */ if (fstat(pfh->pf_fd, &sb) == -1) return (errno); if (sb.st_dev != pfh->pf_dev || sb.st_ino != pfh->pf_ino) return (EDOOFUS); return (0); } static int pidfile_read(int dirfd, const char *filename, pid_t *pidptr) { char buf[16], *endptr; int error, fd, i; fd = openat(dirfd, filename, O_RDONLY | O_CLOEXEC); if (fd == -1) return (errno); i = read(fd, buf, sizeof(buf) - 1); error = errno; /* Remember errno in case close() wants to change it. */ close(fd); if (i == -1) return (error); else if (i == 0) return (EAGAIN); buf[i] = '\0'; *pidptr = strtol(buf, &endptr, 10); if (endptr != &buf[i]) return (EINVAL); return (0); } struct pidfh * pidfile_open(const char *pathp, mode_t mode, pid_t *pidptr) { char path[MAXPATHLEN]; struct pidfh *pfh; struct stat sb; int error, fd, dirfd, dirlen, filenamelen, count; struct timespec rqtp; cap_rights_t caprights; pfh = malloc(sizeof(*pfh)); if (pfh == NULL) return (NULL); if (pathp == NULL) { dirlen = snprintf(pfh->pf_dir, sizeof(pfh->pf_dir), "/var/run/"); filenamelen = snprintf(pfh->pf_filename, sizeof(pfh->pf_filename), "%s.pid", getprogname()); } else { if (strlcpy(path, pathp, sizeof(path)) >= sizeof(path)) { free(pfh); errno = ENAMETOOLONG; return (NULL); } dirlen = strlcpy(pfh->pf_dir, dirname(path), sizeof(pfh->pf_dir)); (void)strlcpy(path, pathp, sizeof(path)); filenamelen = strlcpy(pfh->pf_filename, basename(path), sizeof(pfh->pf_filename)); } if (dirlen >= (int)sizeof(pfh->pf_dir) || filenamelen >= (int)sizeof(pfh->pf_filename)) { free(pfh); errno = ENAMETOOLONG; return (NULL); } dirfd = open(pfh->pf_dir, O_CLOEXEC | O_DIRECTORY | O_NONBLOCK); if (dirfd == -1) { error = errno; free(pfh); errno = error; return (NULL); } /* * Open the PID file and obtain exclusive lock. * We truncate PID file here only to remove old PID immediately, * PID file will be truncated again in pidfile_write(), so * pidfile_write() can be called multiple times. */ fd = flopenat(dirfd, pfh->pf_filename, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC | O_NONBLOCK, mode); if (fd == -1) { if (errno == EWOULDBLOCK) { if (pidptr == NULL) { errno = EEXIST; } else { count = 20; rqtp.tv_sec = 0; rqtp.tv_nsec = 5000000; for (;;) { errno = pidfile_read(dirfd, pfh->pf_filename, pidptr); if (errno != EAGAIN || --count == 0) break; nanosleep(&rqtp, 0); } if (errno == EAGAIN) *pidptr = -1; if (errno == 0 || errno == EAGAIN) errno = EEXIST; } } error = errno; close(dirfd); free(pfh); errno = error; return (NULL); } /* * Remember file information, so in pidfile_write() we are sure we write * to the proper descriptor. */ if (fstat(fd, &sb) == -1) { goto failed; } if (cap_rights_limit(dirfd, cap_rights_init(&caprights, CAP_UNLINKAT)) < 0 && errno != ENOSYS) { goto failed; } if (cap_rights_limit(fd, cap_rights_init(&caprights, CAP_PWRITE, - CAP_FSTAT, CAP_FTRUNCATE)) < 0 && + CAP_FSTAT, CAP_FTRUNCATE, CAP_EVENT)) < 0 && errno != ENOSYS) { goto failed; } pfh->pf_dirfd = dirfd; pfh->pf_fd = fd; pfh->pf_dev = sb.st_dev; pfh->pf_ino = sb.st_ino; return (pfh); failed: error = errno; unlinkat(dirfd, pfh->pf_filename, 0); close(dirfd); close(fd); free(pfh); errno = error; return (NULL); } int pidfile_write(struct pidfh *pfh) { char pidstr[16]; int error, fd; /* * Check remembered descriptor, so we don't overwrite some other * file if pidfile was closed and descriptor reused. */ errno = pidfile_verify(pfh); if (errno != 0) { /* * Don't close descriptor, because we are not sure if it's ours. */ return (-1); } fd = pfh->pf_fd; /* * Truncate PID file, so multiple calls of pidfile_write() are allowed. */ if (ftruncate(fd, 0) == -1) { error = errno; _pidfile_remove(pfh, 0); errno = error; return (-1); } snprintf(pidstr, sizeof(pidstr), "%u", getpid()); if (pwrite(fd, pidstr, strlen(pidstr), 0) != (ssize_t)strlen(pidstr)) { error = errno; _pidfile_remove(pfh, 0); errno = error; return (-1); } return (0); } int pidfile_close(struct pidfh *pfh) { int error; error = pidfile_verify(pfh); if (error != 0) { errno = error; return (-1); } if (close(pfh->pf_fd) == -1) error = errno; if (close(pfh->pf_dirfd) == -1 && error == 0) error = errno; free(pfh); if (error != 0) { errno = error; return (-1); } return (0); } static int _pidfile_remove(struct pidfh *pfh, int freeit) { int error; error = pidfile_verify(pfh); if (error != 0) { errno = error; return (-1); } if (funlinkat(pfh->pf_dirfd, pfh->pf_filename, pfh->pf_fd, 0) == -1) { if (errno == EDEADLK) return (-1); error = errno; } if (close(pfh->pf_fd) == -1 && error == 0) error = errno; if (close(pfh->pf_dirfd) == -1 && error == 0) error = errno; if (freeit) free(pfh); else pfh->pf_fd = -1; if (error != 0) { errno = error; return (-1); } return (0); } int pidfile_remove(struct pidfh *pfh) { return (_pidfile_remove(pfh, 1)); } int pidfile_fileno(const struct pidfh *pfh) { if (pfh == NULL || pfh->pf_fd == -1) { errno = EDOOFUS; return (-1); } return (pfh->pf_fd); }