diff options
Diffstat (limited to 'nixpkgs/pkgs/os-specific/linux/sdnotify-wrapper/sdnotify-wrapper.c')
| -rw-r--r-- | nixpkgs/pkgs/os-specific/linux/sdnotify-wrapper/sdnotify-wrapper.c | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/nixpkgs/pkgs/os-specific/linux/sdnotify-wrapper/sdnotify-wrapper.c b/nixpkgs/pkgs/os-specific/linux/sdnotify-wrapper/sdnotify-wrapper.c deleted file mode 100644 index 3ad3cbc69063..000000000000 --- a/nixpkgs/pkgs/os-specific/linux/sdnotify-wrapper/sdnotify-wrapper.c +++ /dev/null @@ -1,174 +0,0 @@ -/* - Copyright: (C)2015-2020 Laurent Bercot. http://skarnet.org/ - ISC license. See http://opensource.org/licenses/ISC - - Build-time requirements: skalibs. https://skarnet.org/software/skalibs/ - Run-time requirements: none, if you link skalibs statically. - - Compilation: - gcc -o sdnotify-wrapper -L/usr/lib/skalibs sdnotify-wrapper.c -lskarnet - Use /usr/lib/skalibs/libskarnet.a instead of -lskarnet to link statically. - Adapt gcc's -I and -L options to your skalibs installation paths. - - Usage: if a daemon would be launched by systemd as "foobard args...", - launch it as "sdnotify-wrapper foobard args..." instead, and you can now - tell systemd that this daemon supports readiness notification. - - Instead of using sd_notify() and having to link against the systemd - library, the daemon notifies readiness by writing whatever it wants - to a file descriptor (by default: stdout), then a newline. (Then it - should close that file descriptor.) The simplest way is something like - int notify_readiness() { write(1, "\n", 1) ; close(1) ; } - This mechanism is understandable by any notification readiness framework. - - Readiness notification occurs when the newline is written, not when - the descriptor is closed; but since sdnotify-wrapper stops reading - after the first newline and will exit, any subsequent writes will - fail and it's best to simply close the descriptor right away. - - sdnotify-wrapper sees the notification when it occurs and sends it - to systemd using the sd_notify format. - - Options: - -d fd: the daemon will write its notification on descriptor fd. - Default is 1. - -f: do not doublefork. Use if the daemon waits for children it does - not know it has (for instance, superservers do this). When in doubt, - do not use that option, or you may have a zombie hanging around. - -t timeout: if the daemon has not sent a notification after timeout - milliseconds, give up and exit; systemd will not be notified. - -k: keep the NOTIFY_SOCKET environment variable when execing into the - daemon. By default, the variable is unset: the daemon should not need it. - - Notes: - sdnotify-wrapper does not change the daemon's pid. It runs as a - (grand)child of the daemon. - If the NOTIFY_SOCKET environment variable is not set, sdnotify-wrapper - does nothing - it only execs into the daemon. - sdnotify-wrapper is more liberal than sd_notify(). It will accept - a relative path in NOTIFY_SOCKET. -*/ - - -#include <sys/types.h> -#include <string.h> -#include <unistd.h> -#include <stdlib.h> -#include <errno.h> -#include <sys/socket.h> -#include <sys/un.h> - -#include <skalibs/uint64.h> -#include <skalibs/types.h> -#include <skalibs/bytestr.h> -#include <skalibs/sgetopt.h> -#include <skalibs/strerr2.h> -#include <skalibs/allreadwrite.h> -#include <skalibs/tai.h> -#include <skalibs/iopause.h> -#include <skalibs/djbunix.h> -#include <skalibs/socket.h> -#include <skalibs/exec.h> - -#define USAGE "sdnotify-wrapper [ -d fd ] [ -f ] [ -t timeout ] [ -k ] prog..." -#define dieusage() strerr_dieusage(100, USAGE) - -#define VAR "NOTIFY_SOCKET" - -static inline int ipc_sendto (int fd, char const *s, size_t len, char const *path) -{ - struct sockaddr_un sa ; - size_t l = strlen(path) ; - if (l > IPCPATH_MAX) return (errno = ENAMETOOLONG, 0) ; - memset(&sa, 0, sizeof sa) ; - sa.sun_family = AF_UNIX ; - memcpy(sa.sun_path, path, l+1) ; - if (path[0] == '@') sa.sun_path[0] = 0 ; - return sendto(fd, s, len, MSG_NOSIGNAL, (struct sockaddr *)&sa, sizeof sa) >= 0 ; -} - -static inline void notify_systemd (pid_t pid, char const *socketpath) -{ - size_t n = 16 ; - char fmt[16 + PID_FMT] = "READY=1\nMAINPID=" ; - int fd = ipc_datagram_b() ; - if (fd < 0) strerr_diefu1sys(111, "create socket") ; - n += pid_fmt(fmt + n, pid) ; - fmt[n++] = '\n' ; - if (!ipc_sendto(fd, fmt, n, socketpath)) - strerr_diefu2sys(111, "send notification message to ", socketpath) ; - close(fd) ; -} - -static inline int run_child (int fd, unsigned int timeout, pid_t pid, char const *s) -{ - char dummy[4096] ; - iopause_fd x = { .fd = fd, .events = IOPAUSE_READ } ; - tain deadline ; - tain_now_g() ; - if (timeout) tain_from_millisecs(&deadline, timeout) ; - else deadline = tain_infinite_relative ; - tain_add_g(&deadline, &deadline) ; - for (;;) - { - int r = iopause_g(&x, 1, &deadline) ; - if (r < 0) strerr_diefu1sys(111, "iopause") ; - if (!r) return 99 ; - r = sanitize_read(fd_read(fd, dummy, 4096)) ; - if (r < 0) - if (errno == EPIPE) return 1 ; - else strerr_diefu1sys(111, "read from parent") ; - else if (r && memchr(dummy, '\n', r)) break ; - } - close(fd) ; - notify_systemd(pid, s) ; - return 0 ; -} - -int main (int argc, char const *const *argv) -{ - char const *s = getenv(VAR) ; - unsigned int fd = 1 ; - unsigned int timeout = 0 ; - int df = 1, keep = 0 ; - PROG = "sdnotify-wrapper" ; - { - subgetopt l = SUBGETOPT_ZERO ; - for (;;) - { - int opt = subgetopt_r(argc, argv, "d:ft:k", &l) ; - if (opt == -1) break ; - switch (opt) - { - case 'd' : if (!uint0_scan(l.arg, &fd)) dieusage() ; break ; - case 'f' : df = 0 ; break ; - case 't' : if (!uint0_scan(l.arg, &timeout)) dieusage() ; break ; - case 'k' : keep = 1 ; break ; - default : dieusage() ; - } - } - argc -= l.ind ; argv += l.ind ; - } - if (!argc) dieusage() ; - - if (!s) xexec(argv) ; - else - { - pid_t parent = getpid() ; - pid_t child ; - int p[2] ; - if (pipe(p) < 0) strerr_diefu1sys(111, "pipe") ; - child = df ? doublefork() : fork() ; - if (child < 0) strerr_diefu1sys(111, df ? "doublefork" : "fork") ; - else if (!child) - { - PROG = "sdnotify-wrapper (child)" ; - close(p[1]) ; - return run_child(p[0], timeout, parent, s) ; - } - close(p[0]) ; - if (fd_move((int)fd, p[1]) < 0) strerr_diefu1sys(111, "move descriptor") ; - if (keep) xexec(argv) ; - else xmexec_m(argv, VAR, sizeof(VAR)) ; - } -} |