1 files changed, 59 insertions, 0 deletions
diff --git a/src/libs6/s6_auto_write_service.c b/src/libs6/s6_auto_write_service.c
new file mode 100644
index 0000000..c341a55
--- /dev/null
+++ b/src/libs6/s6_auto_write_service.c
@@ -0,0 +1,59 @@
+/* ISC license. */
+
+#include <string.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+
+#include <skalibs/types.h>
+#include <skalibs/buffer.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/strerr.h>
+
+#include <s6/auto.h>
+
+void s6_auto_write_service (char const *dir, unsigned int nfd, s6_buffer_writer_func_ref f, void *data, char const *logger)
+{
+  int fd ;
+  buffer b ;
+  size_t dirlen = strlen(dir) ;
+  mode_t m = umask(0) ;
+  char buf[4096] ;
+  char fn[dirlen + 17] ;
+  if (mkdir(dir, 0755) == -1) strerr_diefu2sys(111, "mkdir ", dir) ;
+  umask(m) ;
+  m = ~m & 0666 ;
+  memcpy(fn, dir, dirlen) ;
+  memcpy(fn + dirlen, "/run", 5) ;
+  fd = open_trunc(fn) ;
+  if (fd == -1) strerr_diefu2sys(111, "open ", fn) ;
+  buffer_init(&b, &buffer_write, fd, buf, 4096) ;
+  if (!(*f)(&b, data)) strerr_diefu2sys(111, "write to ", fn) ;
+  fd_close(fd) ;
+  if (nfd)
+  {
+    char fmt[UINT_FMT] ;
+    size_t l = uint_fmt(fmt, nfd) ;
+    fmt[l++] = '\n' ;
+    memcpy(fn + dirlen + 1, "notification-fd", 16) ;
+    if (!openwritenclose_unsafe(fn, fmt, l)) strerr_diefu2sys(111, "write to ", fn) ;
+  }
+  if (logger)
+  {
+    memcpy(fn + dirlen + 1, "type", 5) ;
+    if (!openwritenclose_unsafe(fn, "longrun\n", 8)) strerr_diefu2sys(111, "write to ", fn) ;
+    if (logger[0])
+    {
+      struct iovec v[2] = { { .iov_base = (char *)logger, .iov_len = strlen(logger) }, { .iov_base = "\n", .iov_len = 1 } } ;
+      memcpy(fn + dirlen + 1, "producer-for", 13) ;
+      if (!openwritevnclose_unsafe(fn, v, 2)) strerr_diefu2sys(111, "write to ", fn) ;
+    }
+  }
+  else
+  {
+    if (chmod(fn, m | ((m >> 2) & 0111)) < 0)
+      strerr_diefu2sys(111, "chmod ", fn) ;
+    if (!(m & 0400))
+      strerr_warnw2x("weird umask, check permissions manually on ", fn) ;
+  }
+}