Initial commit.

1 files changed, 347 insertions, 0 deletions

diff --git a/src/alias/s6-frontend-alias-chpst.c b/src/alias/s6-frontend-alias-chpst.c
new file mode 100644
index 0000000..860654e
--- /dev/null
+++ b/src/alias/s6-frontend-alias-chpst.c
@@ -0,0 +1,347 @@
+ /* ISC license. */
+
+#include <string.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <limits.h>
+#include <errno.h>
+#include <pwd.h>
+#include <grp.h>
+
+#include <skalibs/uint64.h>
+#include <skalibs/types.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/sgetopt.h>
+#include <skalibs/buffer.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+#include <skalibs/env.h>
+#include <skalibs/djbunix.h>
+
+#include <execline/config.h>
+
+#include <s6/config.h>
+
+#define USAGE "s6-frontend-alias-chpst [ -v ] [ -P ] [ -0 ] [ -1 ] [ -2 ] [ -u user ] [ -U user ] [ -b argv0 ] [ -e dir ] [ -n niceness ] [ -l lock | -L lock ] [ -m bytes ] [ -d bytes ] [ -o n ] [ -p n ] [ -f bytes ] [ -c bytes ] prog..."
+
+#define dienomem() strerr_diefu1sys(111, "stralloc_catb")
+#define dieusage() strerr_dieusage(100, USAGE)
+
+static unsigned int verbosity = 0 ;
+
+static void printit (char const *const *argv)
+{
+  buffer_puts(buffer_2, PROG) ;
+  buffer_puts(buffer_2, ": info: executing the following command line:") ;
+  for (; *argv ; argv++)
+  {
+    buffer_puts(buffer_2, " ") ;
+    buffer_puts(buffer_2, *argv) ;
+  }
+  buffer_putsflush(buffer_2, "\n") ;
+}
+
+static inline size_t parseuggnum (char const *s, uint32_t *flags, uid_t *uid, gid_t *gid, gid_t *tab)
+{
+  size_t n = 0 ;
+  size_t pos = uid_scan(s, uid) ;
+  if (!pos) dieusage() ;
+  if (!s[pos]) return 0 ;
+  if (s[pos] != ':') dieusage() ;
+  s += pos+1 ;
+  pos = gid_scan(s, gid) ;
+  if (!pos) dieusage() ;
+  *flags |= 32768 ;
+  if (!s[pos]) return 0 ;
+  if (s[pos] != ':') dieusage() ;
+  s += pos+1 ;
+  if (!gid_scanlist(tab, NGROUPS_MAX, s, &n)) dieusage() ;
+  return n ;
+}
+
+static struct passwd *do_getpwnam (char const *s)
+{
+  struct passwd *pw = getpwnam(s) ;
+  if (!pw)
+  {
+    if (errno) strerr_diefu1sys(111, "read user database") ;
+    else strerr_dief2x(100, "user not found in user database: ", s) ;
+  }
+  return pw ;
+}
+
+static struct group *do_getgrnam (char const *s)
+{
+  struct group *gr = getgrnam(s) ;
+  if (!gr)
+  {
+    if (errno) strerr_diefu1sys(111, "read group database") ;
+    else strerr_dief2x(100, "group not found in group database: ", s) ;
+  }
+  return gr ;
+}
+
+static inline size_t parseuggsym (char const *s, uint32_t *flags, uid_t *uid, gid_t *gid, gid_t *tab)
+{
+  size_t n = 0 ;
+  struct passwd *pw ;
+  struct group *gr ;
+  size_t pos = str_chr(s, ':') ;
+  *flags |= 32768 ;
+  errno = 0 ;
+  if (!s[pos]) pw = do_getpwnam(s) ;
+  else
+  {
+    char tmp[pos+1] ;
+    memcpy(tmp, s, pos) ;
+    tmp[pos] = 0 ;
+    pw = do_getpwnam(tmp) ;
+  }
+  *uid = pw->pw_uid ;
+  if (!s[pos])
+  {
+    *gid = pw->pw_gid ;
+    return 0 ;
+  }
+  s += pos+1 ;
+  pos = str_chr(s, ':') ;
+  errno = 0 ;
+  if (!s[pos]) gr = do_getgrnam(s) ;
+  else
+  {
+    char tmp[pos+1] ;
+    memcpy(tmp, s, pos) ;
+    tmp[pos] = 0 ;
+    gr = do_getgrnam(tmp) ;
+  }
+  *gid = gr->gr_gid ;
+  if (!s[pos]) return 0 ;
+  s += pos+1 ;
+  while (*s)
+  {
+    if (n >= NGROUPS_MAX)
+      strerr_dief1x(100, "too many supplementary groups listed for the -u option") ;
+    pos = str_chr(s, ':') ;
+    errno = 0 ;
+    if (!s[pos]) gr = do_getgrnam(s) ;
+    else
+    {
+      char tmp[pos+1] ;
+      memcpy(tmp, s, pos) ;
+      tmp[pos] = 0 ;
+      gr = do_getgrnam(tmp) ;
+    }
+    tab[n++] = gr->gr_gid ;
+    s += s[pos] ? pos+1 : pos ;
+  }
+  return n ;
+}
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  static char const *valopt[6] = { "-m", "-d", "-o", "-p", "-f", "-c" } ;
+  genalloc envdirs = GENALLOC_ZERO ; /* char const * */
+  stralloc newroot = STRALLOC_ZERO ;
+  unsigned int newargc = 0 ;
+  char const *argv0 = 0 ;
+  char const *lockfile = 0 ;
+  char const *envug = 0 ;
+  uint32_t flags = 0 ;
+  int niceval = 0 ;
+  char valfmt[6][UINT64_FMT] ;
+  char nicefmt[INT_FMT] ;
+  char uidfmt[UID_FMT] ;
+  char gidfmt[GID_FMT] ;
+  char gidlistfmt[GID_FMT * NGROUPS_MAX] ;
+  PROG = "s6-frontend-alias-chpst" ;
+
+  {
+    subgetopt_t l = SUBGETOPT_ZERO ;
+    for (;;)
+    {
+      int opt = subgetopt_r(argc, argv, "vP012u:U:b:e:/:n:l:L:m:d:o:p:f:c:", &l) ;
+      if (opt == -1) break ;
+      switch (opt)
+      {
+        case 'v' : verbosity++ ; break ;
+        case '0' : flags |= 1 ; newargc += 2 ; break ;
+        case '1' : flags |= 2 ; newargc += 2 ; break ;
+        case '2' : flags |= 4 ; newargc += 2 ; break ;
+        case 'P' : flags |= 8 ; newargc += 2 ; break ;
+        case 'b' : argv0 = l.arg ; newargc += 4 ; break ;
+        case 'u' :
+        {
+          size_t n ;
+          uid_t uid ;
+          gid_t gid ;
+          gid_t tab[NGROUPS_MAX] ;
+          newargc += 6 ;
+          flags |= 16384 ; flags &= ~32768 ;
+          n = l.arg[0] == ':' ?
+            parseuggnum(l.arg + 1, &flags, &uid, &gid, tab) :
+            parseuggsym(l.arg, &flags, &uid, &gid, tab) ;
+          uidfmt[uid_fmt(uidfmt, uid)] = 0 ;
+          if (flags & 32768)
+          {
+            newargc += 2 ;
+            gidfmt[gid_fmt(gidfmt, gid)] = 0 ;
+          }
+          gidlistfmt[gid_fmtlist(gidlistfmt, tab, n)] = 0 ;
+          break ;
+        }
+        case 'U' :
+          envug = l.arg ;
+          newargc += 3 ;
+          if (envug[0] == ':') { flags |= 4096 ; envug++ ; newargc++ ; } else flags &= ~4096 ;
+          if (strchr(envug, ':')) { flags |= 8192 ; newargc++ ; } else flags &= ~8192 ;
+          break ;
+        case 'e' :
+          if (!genalloc_append(char const *, &envdirs, &l.arg)) dienomem() ;
+          newargc += 3 ;
+          break ;
+        case '/' :
+          newroot.len = 0 ;
+          if (sarealpath(&newroot, l.arg) < 0 || !stralloc_0(&newroot)) dienomem() ;
+          newargc += 2 ;
+          break ;
+        case 'n' :
+          if (!int0_scan(l.arg, &niceval)) dieusage() ;
+          newargc += 3 ;
+          break ;
+        case 'l' : lockfile = l.arg ; flags &= ~16 ; newargc += 4 ; break ;
+        case 'L' : lockfile = l.arg ; flags |= 16 ; newargc += 4 ; break ;
+        case 'm' :
+        case 'd' :
+        case 'o' :
+        case 'p' :
+        case 'f' :
+        case 'c' :
+        {
+          uint64_t val ;
+          size_t pos = byte_chr("mdopfc", 6, opt) ;
+          if (!uint640_scan(l.arg, &val)) dieusage() ;
+          valfmt[pos][uint64_fmt(valfmt[pos], val)] = 0 ;
+          flags |= 32 | (1 << (6 + pos)) ;
+          newargc += 2 ;
+          break ;
+        }
+        default : dieusage() ;
+      }
+    }
+    argc -= l.ind ; argv += l.ind ;
+  }
+
+  if (flags & 32) newargc += 2 ;
+  newargc += argc ;
+
+  {
+    unsigned int m = 0 ;
+    char const *newargv[newargc + 1] ;
+
+    if (niceval)
+    {
+      nicefmt[int_fmt(nicefmt, niceval)] = 0 ;
+      newargv[m++] = "nice" ;
+      newargv[m++] = "-n" ;
+      newargv[m++] = nicefmt ;
+      newargv[m++] = "--" ;
+    }
+
+    if (flags & 8)
+    {
+      newargv[m++] = S6_EXTBINPREFIX "s6-setsid" ;
+      newargv[m++] = "--" ;
+    }
+
+    if (genalloc_len(char const *, &envdirs))
+    {
+      for (size_t i = 0 ; i < genalloc_len(char const *, &envdirs) ; i++)
+      {
+        newargv[m++] = S6_EXTBINPREFIX "s6-envdir" ;
+        newargv[m++] = "--" ;
+        newargv[m++] = genalloc_s(char const *, &envdirs)[i] ;
+      }
+    }
+
+    if (lockfile)
+    {
+      newargv[m++] = S6_EXTBINPREFIX "s6-setlock" ;
+      newargv[m++] = flags & 16 ? "-n" : "-N" ;
+      newargv[m++] = "--" ;
+      newargv[m++] = lockfile ;
+    }
+
+    if (flags & 16384)
+    {
+      newargv[m++] = S6_EXTBINPREFIX "s6-applyuidgid" ;
+      newargv[m++] = "-u" ;
+      newargv[m++] = uidfmt ;
+      if (flags & 32768)
+      {
+        newargv[m++] = "-g" ;
+        newargv[m++] = gidfmt ;
+      }
+      newargv[m++] = "-G" ;
+      newargv[m++] = gidlistfmt ;
+      newargv[m++] = "--" ;
+    }
+
+    if (envug)
+    {
+      newargv[m++] = S6_EXTBINPREFIX "s6-envuidgid" ;
+      if (flags & 4096) newargv[m++] = "-n" ;
+      if (flags & 8192) newargv[m++] = "-B" ;
+      newargv[m++] = "--" ;
+      newargv[m++] = envug ;
+    }
+
+    if (flags & 32)
+    {
+      newargv[m++] = S6_EXTBINPREFIX "s6-softlimit" ;
+      for (unsigned int i = 0 ; i < 6 ; i++) if (flags & (1 << (i + 6)))
+      {
+        newargv[m++] = valopt[i] ;
+        newargv[m++] = valfmt[i] ;
+      }
+      newargv[m++] = "--" ;
+    }
+
+    if (flags & 1)
+    {
+      newargv[m++] = EXECLINE_EXTBINPREFIX "fdclose" ;
+      newargv[m++] = "0" ;
+    }
+
+    if (flags & 2)
+    {
+      newargv[m++] = EXECLINE_EXTBINPREFIX "fdclose" ;
+      newargv[m++] = "1" ;
+    }
+
+    if (flags & 4)
+    {
+      newargv[m++] = EXECLINE_EXTBINPREFIX "fdclose" ;
+      newargv[m++] = "2" ;
+    }
+
+    if (argv0)
+    {
+      newargv[m++] = EXECLINE_BINPREFIX "exec" ;
+      newargv[m++] = "-a" ;
+      newargv[m++] = argv0 ;
+      newargv[m++] = "--" ;
+    }
+
+    if (newroot.s)
+    {
+      newargv[m++] = "chroot" ;
+      newargv[m++] = newroot.s ;
+      if (argv0) strerr_warnw1x("the -b option is ineffective when the -/ option is also given") ;
+    }
+
+    for (int i = 0 ; i < argc+1 ; i++) newargv[m++] = argv[i] ;
+    if (verbosity) printit(newargv) ;
+    xpathexec0_run(newargv, envp) ;
+  }
+}