From abbbea81a8fa70badb7a05e518d6b07c360fc09d Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Sun, 16 May 2010 01:43:53 +0200 Subject: [PATCH] sd-daemon: add reference implementation of various daemon apis --- sd-daemon.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++++ sd-daemon.h | 61 ++++++++++++++++++++++++++++++++++ 2 files changed, 157 insertions(+) create mode 100644 sd-daemon.c create mode 100644 sd-daemon.h diff --git a/sd-daemon.c b/sd-daemon.c new file mode 100644 index 000000000..cc972dabd --- /dev/null +++ b/sd-daemon.c @@ -0,0 +1,96 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +/*** + Copyright 2010 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +#include +#include +#include +#include + +#include "sd-daemon.h" + +int sd_listen_fds(int unset_environment) { + +#ifdef DISABLE_SYSTEMD + return 0; +#else + int r; + const char *e; + char *p = NULL; + unsigned long l; + + if (!(e = getenv("LISTEN_PID"))) { + r = 0; + goto finish; + } + + errno = 0; + l = strtoul(e, &p, 10); + + if (errno != 0) { + r = -errno; + goto finish; + } + + if (!p || *p || l <= 0) { + r = -EINVAL; + goto finish; + } + + /* Is this for us? */ + if (getpid() != (pid_t) l) { + r = 0; + goto finish; + } + + if (!(e = getenv("LISTEN_FDS"))) { + r = 0; + goto finish; + } + + errno = 0; + l = strtoul(e, &p, 10); + + if (errno != 0) { + r = -errno; + goto finish; + } + + if (!p || *p) { + r = -EINVAL; + goto finish; + } + + r = (int) l; + +finish: + if (unset_environment) { + unsetenv("LISTEN_PID"); + unsetenv("LISTEN_FDS"); + } + + return r; +#endif +} diff --git a/sd-daemon.h b/sd-daemon.h new file mode 100644 index 000000000..c7f5c1d6b --- /dev/null +++ b/sd-daemon.h @@ -0,0 +1,61 @@ +/*-*- Mode: C; c-basic-offset: 8 -*-*/ + +#ifndef foosddaemonhfoo +#define foosddaemonhfoo + +/*** + Copyright 2010 Lennart Poettering + + Permission is hereby granted, free of charge, to any person + obtaining a copy of this software and associated documentation files + (the "Software"), to deal in the Software without restriction, + including without limitation the rights to use, copy, modify, merge, + publish, distribute, sublicense, and/or sell copies of the Software, + and to permit persons to whom the Software is furnished to do so, + subject to the following conditions: + + The above copyright notice and this permission notice shall be + included in all copies or substantial portions of the Software. + + THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + SOFTWARE. +***/ + +/* Reference implementation of a few systemd related interfaces for + * writing daemons. These interfaces are trivial to implement, however + * to simplify porting we provide this reference + * implementation. Applications are free to reimplement the algorithms + * described here. */ + +/* + Log levels for usage on stderr: + + fprintf(stderr, SD_NOTICE "Hello World!"); + + This is similar to printk() usage in the kernel. +*/ + +#define SD_EMERG "<0>" /* system is unusable */ +#define SD_ALERT "<1>" /* action must be taken immediately */ +#define SD_CRIT "<2>" /* critical conditions */ +#define SD_ERR "<3>" /* error conditions */ +#define SD_WARNING "<4>" /* warning conditions */ +#define SD_NOTICE "<5>" /* normal but significant condition */ +#define SD_INFO "<6>" /* informational */ +#define SD_DEBUG "<7>" /* debug-level messages */ + +/* The first passed file descriptor is fd 3 */ +#define SD_LISTEN_FDS_START 3 + +/* Returns how many file descriptors have been passed, or a negative + * errno code on failure. Optionally removes the $LISTEN_FDS and + * $LISTEN_PID file descriptors from the environment (recommended). */ +int sd_listen_fds(int unset_environment); + +#endif -- 2.30.2