Bloat envdir with a noclamp option

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 85 insertions, 0 deletions

diff --git a/src/libenvexec/envdir_clamp.c b/src/libenvexec/envdir_clamp.c
new file mode 100644
index 0000000..b63ed97
--- /dev/null
+++ b/src/libenvexec/envdir_clamp.c
@@ -0,0 +1,85 @@
+/* ISC license. */
+
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include <skalibs/bytestr.h>
+#include <skalibs/env.h>
+#include <skalibs/direntry.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/djbunix.h>
+#include "envdir-internal.h"
+
+#define MAXVARSIZE 4095
+
+int envdir_internal_clamp (char const *path, stralloc *modifs, unsigned int options, char nullis)
+{
+  char buf[MAXVARSIZE + 1] ;
+  unsigned int n = 0 ;
+  size_t pathlen = strlen(path) ;
+  size_t modifbase = modifs->len ;
+  int wasnull = !modifs->s ;
+  DIR *dir = opendir(path) ;
+  if (!dir) return -1 ;
+  for (;;)
+  {
+    direntry *d ;
+    size_t len ;
+    ssize_t r ;
+    errno = 0 ;
+    d = readdir(dir) ;
+    if (!d) break ;
+    if (d->d_name[0] == '.') continue ;
+    len = strlen(d->d_name) ;
+    if (str_chr(d->d_name, '=') < len) continue ;
+    {
+      char tmp[pathlen + len + 2] ;
+      memcpy(tmp, path, pathlen) ;
+      tmp[pathlen] = '/' ;
+      memcpy(tmp + pathlen + 1, d->d_name, len + 1) ;
+      r = openreadnclose(tmp, buf, MAXVARSIZE) ;
+    }
+    if (r < 0)
+    {
+      if (errno == ENOENT) errno = EIDRM ;
+      goto err ;
+    }
+    else if (r > 0)
+    {
+      if (options & SKALIBS_ENVDIR_VERBATIM)
+      {
+        if (!(options & SKALIBS_ENVDIR_NOCHOMP) && (buf[r-1] == '\n')) r-- ;
+      }
+      else
+      {
+        r = byte_chr(buf, r, '\n') ;
+        if (!(options & SKALIBS_ENVDIR_NOCHOMP))
+        {
+          while (r--) if ((buf[r] != ' ') && (buf[r] != '\t') && (buf[r] != '\r')) break ;
+          r++ ;
+        }
+      }
+      {
+        size_t i = 0 ;
+        for (; i < (size_t)r ; i++) if (!buf[i]) buf[i] = nullis ;
+      }
+      buf[r++] = 0 ;
+      if (!env_addmodif(modifs, d->d_name, buf)) goto err ;
+    }
+    else if (!env_addmodif(modifs, d->d_name, 0)) goto err ;
+    n++ ;
+  }
+  if (errno) goto err ;
+  dir_close(dir) ;
+  return n ;
+
+ err:
+  {
+    int e = errno ;
+    dir_close(dir) ;
+    if (wasnull) stralloc_free(modifs) ; else modifs->len = modifbase ;
+    errno = e ;
+    return -1 ;
+  }
+}