summaryrefslogtreecommitdiff
path: root/src/libs6/s6_supervise_link.c
blob: 7d97f4ad02295f866d3befa1a58d1373a271c29d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/* 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 *scandir, char const *prefix, size_t prefixlen, size_t maxlen, char const *names, size_t nameslen, uint32_t killopts)
{
  char fn[prefixlen + maxlen + 1] ;
  memcpy(fn, prefix, prefixlen) ;
  while (nameslen)
  {
    size_t len = strlen(names) + 1 ;
    memcpy(fn + prefixlen, names, len) ;
    s6_supervise_unlink(scandir, fn, 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 + 5 + sizeof(S6_SUPERVISE_EVENTDIR)] ;
    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))
    {
      char *p ;
      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 ;
      if (bitarray_peek(logged, i))
      {
        memcpy(fn + len, "/log/", 5) ;
        memcpy(fn + len + 5, 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, p, 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, prefix, prefixlen, maxlen, lnames.s, lnames.len, killopts) ;
    stralloc_free(&lnames) ;
    return -1 ;
  }
}