detach.c revision 1.2.16.2
1 1.2.16.2 snj /* $NetBSD: detach.c,v 1.2.16.2 2017/08/20 05:46:43 snj Exp $ */ 2 1.2.16.2 snj 3 1.2.16.2 snj /*- 4 1.2.16.2 snj * Copyright (c) 2015 5 1.2.16.2 snj * Cryptonector LLC. All rights reserved. 6 1.2.16.2 snj * 7 1.2.16.2 snj * Redistribution and use in source and binary forms, with or without 8 1.2.16.2 snj * modification, are permitted provided that the following conditions 9 1.2.16.2 snj * are met: 10 1.2.16.2 snj * 1. Redistributions of source code must retain the above copyright 11 1.2.16.2 snj * notice, this list of conditions and the following disclaimer. 12 1.2.16.2 snj * 2. Redistributions in binary form must reproduce the above copyright 13 1.2.16.2 snj * notice, this list of conditions and the following disclaimer in the 14 1.2.16.2 snj * documentation and/or other materials provided with the distribution. 15 1.2.16.2 snj * 3. Cryptonector LLC may not be used to endorse or promote products 16 1.2.16.2 snj * derived from this software without specific prior written 17 1.2.16.2 snj * permission. 18 1.2.16.2 snj * 19 1.2.16.2 snj * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 1.2.16.2 snj * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 1.2.16.2 snj * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 1.2.16.2 snj * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 1.2.16.2 snj * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 1.2.16.2 snj * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 1.2.16.2 snj * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 1.2.16.2 snj * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 1.2.16.2 snj * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 1.2.16.2 snj * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 1.2.16.2 snj * SUCH DAMAGE. 30 1.2.16.2 snj */ 31 1.2.16.2 snj 32 1.2.16.2 snj #include <config.h> 33 1.2.16.2 snj #include <errno.h> 34 1.2.16.2 snj #include <fcntl.h> 35 1.2.16.2 snj #ifdef WIN32 36 1.2.16.2 snj #include <io.h> 37 1.2.16.2 snj #include <stdlib.h> 38 1.2.16.2 snj #else 39 1.2.16.2 snj #include <unistd.h> 40 1.2.16.2 snj #endif 41 1.2.16.2 snj #include <krb5/roken.h> 42 1.2.16.2 snj 43 1.2.16.2 snj #ifdef WIN32 44 1.2.16.2 snj #define dup2 _dup2 45 1.2.16.2 snj #endif 46 1.2.16.2 snj 47 1.2.16.2 snj static int pipefds[2] = {-1, -1}; 48 1.2.16.2 snj 49 1.2.16.2 snj ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL 50 1.2.16.2 snj roken_detach_prep(int argc, char **argv, char *special_arg) 51 1.2.16.2 snj { 52 1.2.16.2 snj pid_t child; 53 1.2.16.2 snj char buf[1]; 54 1.2.16.2 snj ssize_t bytes; 55 1.2.16.2 snj int status; 56 1.2.16.2 snj 57 1.2.16.2 snj pipefds[0] = -1; 58 1.2.16.2 snj pipefds[1] = -1; 59 1.2.16.2 snj 60 1.2.16.2 snj #ifdef WIN32 61 1.2.16.2 snj if (_pipe(pipefds, 4, O_BINARY) == -1) 62 1.2.16.2 snj err(1, "failed to setup to detach daemon (_pipe failed)"); 63 1.2.16.2 snj #else 64 1.2.16.2 snj if (pipe(pipefds) == -1) 65 1.2.16.2 snj err(1, "failed to setup to detach daemon (pipe failed)"); 66 1.2.16.2 snj #endif 67 1.2.16.2 snj 68 1.2.16.2 snj #ifndef WIN32 69 1.2.16.2 snj fflush(stdout); 70 1.2.16.2 snj child = fork(); 71 1.2.16.2 snj #else 72 1.2.16.2 snj { 73 1.2.16.2 snj intptr_t child_handle; 74 1.2.16.2 snj int write_side; 75 1.2.16.2 snj size_t i; 76 1.2.16.2 snj char *fildes; 77 1.2.16.2 snj char **new_argv; 78 1.2.16.2 snj 79 1.2.16.2 snj new_argv = calloc(argc + 2, sizeof(*new_argv)); 80 1.2.16.2 snj if (new_argv == NULL) 81 1.2.16.2 snj err(1, "Out of memory"); 82 1.2.16.2 snj 83 1.2.16.2 snj write_side = _dup(pipefds[1]); /* The new fd will be inherited */ 84 1.2.16.2 snj if (write_side == -1) 85 1.2.16.2 snj err(1, "Out of memory"); 86 1.2.16.2 snj 87 1.2.16.2 snj if (asprintf(&fildes, "%d", write_side) == -1 || 88 1.2.16.2 snj fildes == NULL) 89 1.2.16.2 snj err(1, "failed to setup to detach daemon (_dup failed)"); 90 1.2.16.2 snj 91 1.2.16.2 snj new_argv[0] = argv[0]; 92 1.2.16.2 snj new_argv[1] = special_arg; 93 1.2.16.2 snj new_argv[2] = fildes; 94 1.2.16.2 snj for (i = 1; argv[i] != NULL; i++) 95 1.2.16.2 snj new_argv[i + 1] = argv[i]; 96 1.2.16.2 snj new_argv[argc + 2] = NULL; 97 1.2.16.2 snj 98 1.2.16.2 snj _flushall(); 99 1.2.16.2 snj child_handle = spawnvp(_P_NOWAIT, argv[0], new_argv); 100 1.2.16.2 snj if (child_handle == -1) 101 1.2.16.2 snj child = (pid_t)-1; 102 1.2.16.2 snj else 103 1.2.16.2 snj child = GetProcessId((HANDLE)child_handle); 104 1.2.16.2 snj } 105 1.2.16.2 snj #endif 106 1.2.16.2 snj if (child == (pid_t)-1) 107 1.2.16.2 snj err(1, "failed to setup to fork daemon (fork failed)"); 108 1.2.16.2 snj 109 1.2.16.2 snj #ifndef WIN32 110 1.2.16.2 snj if (child == 0) { 111 1.2.16.2 snj int fd; 112 1.2.16.2 snj 113 1.2.16.2 snj (void) close(pipefds[0]); 114 1.2.16.2 snj pipefds[0] = -1; 115 1.2.16.2 snj /* 116 1.2.16.2 snj * Keep stdout/stderr for now so output and errors prior to 117 1.2.16.2 snj * detach_finish() can be seen by the user. 118 1.2.16.2 snj */ 119 1.2.16.2 snj fd = open(_PATH_DEVNULL, O_RDWR, 0); 120 1.2.16.2 snj if (fd == -1) 121 1.2.16.2 snj err(1, "failed to open /dev/null"); 122 1.2.16.2 snj (void) dup2(fd, STDIN_FILENO); 123 1.2.16.2 snj if (fd > STDERR_FILENO) 124 1.2.16.2 snj (void) close(fd); 125 1.2.16.2 snj return; 126 1.2.16.2 snj } 127 1.2.16.2 snj #endif 128 1.2.16.2 snj 129 1.2.16.2 snj (void) close(pipefds[1]); 130 1.2.16.2 snj pipefds[1] = -1; 131 1.2.16.2 snj do { 132 1.2.16.2 snj bytes = read(pipefds[0], buf, sizeof(buf)); 133 1.2.16.2 snj } while (bytes == -1 && errno == EINTR); 134 1.2.16.2 snj (void) close(pipefds[0]); 135 1.2.16.2 snj pipefds[0] = -1; 136 1.2.16.2 snj if (bytes == -1) { 137 1.2.16.2 snj /* 138 1.2.16.2 snj * No need to wait for the process. We've killed it. If it 139 1.2.16.2 snj * doesn't want to exit, we'd have to wait potentially forever, 140 1.2.16.2 snj * but we want to indicate failure to the user as soon as 141 1.2.16.2 snj * possible. A wait with timeout would end the same way 142 1.2.16.2 snj * (attempting to kill the process). 143 1.2.16.2 snj */ 144 1.2.16.2 snj err(1, "failed to setup daemon child (read from child pipe)"); 145 1.2.16.2 snj } 146 1.2.16.2 snj if (bytes == 0) { 147 1.2.16.2 snj warnx("daemon child preparation failed, waiting for child"); 148 1.2.16.2 snj status = wait_for_process(child); 149 1.2.16.2 snj if (SE_IS_ERROR(status) || SE_PROCSTATUS(status) != 0) 150 1.2.16.2 snj errx(SE_PROCSTATUS(status), 151 1.2.16.2 snj "daemon child preparation failed (child exited)"); 152 1.2.16.2 snj } 153 1.2.16.2 snj _exit(0); 154 1.2.16.2 snj } 155 1.2.16.2 snj 156 1.2.16.2 snj #ifdef WIN32 157 1.2.16.2 snj #ifdef dup2 158 1.2.16.2 snj #undef dup2 159 1.2.16.2 snj #endif 160 1.2.16.2 snj #define dup2 _dup2 161 1.2.16.2 snj #endif 162 1.2.16.2 snj 163 1.2.16.2 snj ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL 164 1.2.16.2 snj roken_detach_finish(const char *dir, int daemon_child_fd) 165 1.2.16.2 snj { 166 1.2.16.2 snj char buf[1] = ""; 167 1.2.16.2 snj ssize_t bytes; 168 1.2.16.2 snj int fd; 169 1.2.16.2 snj 170 1.2.16.2 snj rk_pidfile(NULL); 171 1.2.16.2 snj if (pipefds[1] == -1 && daemon_child_fd != -1) 172 1.2.16.2 snj pipefds[1] = daemon_child_fd; 173 1.2.16.2 snj if (pipefds[0] != -1) 174 1.2.16.2 snj (void) close(pipefds[0]); 175 1.2.16.2 snj if (pipefds[1] == -1) 176 1.2.16.2 snj return; 177 1.2.16.2 snj 178 1.2.16.2 snj #ifdef HAVE_SETSID 179 1.2.16.2 snj if (setsid() == -1) 180 1.2.16.2 snj err(1, "failed to detach from tty"); 181 1.2.16.2 snj #endif 182 1.2.16.2 snj 183 1.2.16.2 snj #ifndef WIN32 184 1.2.16.2 snj /* 185 1.2.16.2 snj * Hopefully we've written any pidfiles by now, if they had to be in 186 1.2.16.2 snj * the current directory... 187 1.2.16.2 snj * 188 1.2.16.2 snj * The daemons do re-open logs and so on, therefore this chdir() 189 1.2.16.2 snj * call needs to be optional for testing. 190 1.2.16.2 snj */ 191 1.2.16.2 snj if (dir != NULL && chdir(dir) == -1) 192 1.2.16.2 snj err(1, "failed to chdir to /"); 193 1.2.16.2 snj #endif 194 1.2.16.2 snj 195 1.2.16.2 snj do { 196 1.2.16.2 snj bytes = write(pipefds[1], buf, sizeof(buf)); 197 1.2.16.2 snj } while (bytes == -1 && errno == EINTR); 198 1.2.16.2 snj if (bytes == -1) 199 1.2.16.2 snj err(1, "failed to signal parent while detaching"); 200 1.2.16.2 snj (void) close(pipefds[1]); 201 1.2.16.2 snj if (bytes != sizeof(buf)) 202 1.2.16.2 snj errx(1, "failed to signal parent while detaching"); 203 1.2.16.2 snj 204 1.2.16.2 snj fd = open(_PATH_DEVNULL, O_RDWR, 0); 205 1.2.16.2 snj if (fd == -1) 206 1.2.16.2 snj err(1, "failed to open /dev/null"); 207 1.2.16.2 snj /* 208 1.2.16.2 snj * Maybe we should check that our output got written, if redirected 209 1.2.16.2 snj * to a file. File utils normally do this. 210 1.2.16.2 snj */ 211 1.2.16.2 snj (void) dup2(fd, STDOUT_FILENO); 212 1.2.16.2 snj (void) dup2(fd, STDERR_FILENO); 213 1.2.16.2 snj if (fd > 2) 214 1.2.16.2 snj (void) close(fd); 215 1.2.16.2 snj } 216
Indexes created Thu Apr 09 00:23:28 UTC 2026