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path: root/src/libs6/s6_supervise_link.c
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Diffstat (limited to 'src/libs6/s6_supervise_link.c')
-rw-r--r--src/libs6/s6_supervise_link.c124
1 files changed, 124 insertions, 0 deletions
diff --git a/src/libs6/s6_supervise_link.c b/src/libs6/s6_supervise_link.c
new file mode 100644
index 0000000..4724421
--- /dev/null
+++ b/src/libs6/s6_supervise_link.c
@@ -0,0 +1,124 @@
+/* ISC license. */
+
+#include <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <libgen.h>
+#include <errno.h>
+#include <sys/stat.h>
+
+#include <skalibs/bitarray.h>
+#include <skalibs/tai.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+
+#include <s6/ftrigr.h>
+#include <s6/ftrigw.h>
+#include <s6/s6-supervise.h>
+
+static inline void do_unlink (char const *const scandir, char const *names, size_t nameslen, uint32_t killopts)
+{
+ while (nameslen)
+ {
+ size_t len = strlen(names) + 1 ;
+ s6_supervise_unlink(scandir, names, killopts) ;
+ names += len ; nameslen -= len ;
+ }
+}
+
+int s6_supervise_link (char const *scandir, char const *const *servicedirs, size_t n, char const *prefix, uint32_t options, tain_t const *deadline, tain_t *stamp)
+{
+ size_t maxlen = 0 ;
+ size_t ntotal = n ;
+ unsigned char locked[bitarray_div8(n)] ;
+ unsigned char logged[bitarray_div8(n)] ;
+ if (!n) return 0 ;
+ memset(locked, 0, bitarray_div8(n)) ;
+ memset(logged, 0, bitarray_div8(n)) ;
+
+ for (size_t i = 0 ; i < n ; i++)
+ {
+ struct stat st ;
+ size_t len = strlen(servicedirs[i]) ;
+ int h ;
+ char subdir[len + 5] ;
+ if (len > maxlen) maxlen = len ;
+ h = s6_svc_ok(servicedirs[i]) ;
+ if (h < 0) return -1 ;
+ if (h) bitarray_set(locked, i) ;
+ memcpy(subdir, servicedirs[i], len) ;
+ memcpy(subdir + len, "/log", 5) ;
+ if (stat(subdir, &st) < 0)
+ {
+ if (errno != ENOENT) return -1 ;
+ }
+ else
+ {
+ int r ;
+ if (!S_ISDIR(st.st_mode)) return (errno = ENOTDIR, -1) ;
+ r = s6_svc_ok(subdir) ;
+ if (r < 0) return -1 ;
+ if (r != h) return (errno = EINVAL, -1) ;
+ bitarray_set(logged, i) ;
+ ntotal++ ;
+ }
+ }
+
+ {
+ ftrigr_t a = FTRIGR_ZERO ;
+ stralloc rpsa = STRALLOC_ZERO ;
+ stralloc lnames = STRALLOC_ZERO ;
+ gid_t gid = options & 2 ? -1 : getegid() ;
+ size_t scandirlen = strlen(scandir) ;
+ size_t prefixlen = strlen(prefix) ;
+ unsigned int m = 0 ;
+ size_t i = 0 ;
+ size_t lstart = 0 ;
+ uint32_t killopts = 0 ;
+ int r ;
+ uint16_t ids[ntotal] ;
+ char lname[scandirlen + prefixlen + maxlen + 2] ;
+ char fn[maxlen + 1 + sizeof(S6_SUPERVISE_EVENTDIR)] ;
+ char *p ;
+ if (!ftrigr_startf(&a, deadline, stamp)) return -1 ;
+ memcpy(lname, scandir, scandirlen) ;
+ lname[scandirlen] = '/' ;
+ memcpy(lname + scandirlen + 1, prefix, prefixlen) ;
+ for (i = 0 ; i < n ; i++) if (!bitarray_peek(locked, i))
+ {
+ size_t len = strlen(servicedirs[i]) ;
+ memcpy(fn, servicedirs[i], len) ;
+ memcpy(fn + len, S6_SUPERVISE_EVENTDIR, sizeof(S6_SUPERVISE_EVENTDIR)) ;
+ if (!ftrigw_fifodir_make(fn, gid, options & 1)) goto err ;
+ ids[m] = ftrigr_subscribe(&a, fn, "s", 0, deadline, stamp) ;
+ if (!ids[m++]) goto err ;
+ fn[len] = 0 ;
+ p = basename(fn) ;
+ len = strlen(p) ;
+ memcpy(lname + scandirlen + 1 + prefixlen, p, len + 1) ;
+ rpsa.len = 0 ;
+ lstart = lnames.len ;
+ if (!sarealpath(&rpsa, servicedirs[i]) || !stralloc_0(&rpsa)) goto err ;
+ if (!stralloc_catb(&lnames, lname + scandirlen + 1, prefixlen + len + 1)) goto err ;
+ if (symlink(rpsa.s, lname) < 0) goto errl ;
+ }
+ stralloc_free(&rpsa) ;
+ r = s6_svc_writectl(scandir, S6_SVSCAN_CTLDIR, "a", 1) ;
+ if (r <= 0) goto errsa ;
+ killopts = 3 ;
+ if (ftrigr_wait_and(&a, ids, m, deadline, stamp) < 0) goto errsa ;
+ ftrigr_end(&a) ;
+ stralloc_free(&lnames) ;
+ return m ;
+
+ errl:
+ lnames.len = lstart ;
+ err:
+ stralloc_free(&rpsa) ;
+ errsa:
+ ftrigr_end(&a) ;
+ do_unlink(scandir, lnames.s, lnames.len, killopts) ;
+ stralloc_free(&lnames) ;
+ return -1 ;
+ }
+}