X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=lib%2Fopenat-proc.c;h=87137eec538d4830d4790584cf666750e349689e;hb=92249085071a973e2c0621b0415b93d2e48bb00d;hp=186cda0833aa3ede3ff3241292dd4061c434db7d;hpb=4ee107046a0ffd91f6c60c787326a5e27b799f6d;p=debian%2Fgzip
diff --git a/lib/openat-proc.c b/lib/openat-proc.c
index 186cda0..87137ee 100644
--- a/lib/openat-proc.c
+++ b/lib/openat-proc.c
@@ -1,6 +1,6 @@
/* Create /proc/self/fd-related names for subfiles of open directories.
- Copyright (C) 2006, 2009-2012 Free Software Foundation, Inc.
+ Copyright (C) 2006, 2009-2018 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -13,7 +13,7 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program. If not, see . */
+ along with this program. If not, see . */
/* Written by Paul Eggert. */
@@ -30,32 +30,21 @@
#include
#include
-#include "intprops.h"
-
-/* The results of open() in this file are not used with fchdir,
- and we do not leak fds to any single-threaded code that could use stdio,
- therefore save some unnecessary work in fchdir.c.
- FIXME - if the kernel ever adds support for multi-thread safety for
- avoiding standard fds, then we should use open_safer. */
-#undef open
-#undef close
-
-#define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/%s"
-
-#define PROC_SELF_FD_NAME_SIZE_BOUND(len) \
- (sizeof PROC_SELF_FD_FORMAT - sizeof "%d%s" \
- + INT_STRLEN_BOUND (int) + (len) + 1)
+#ifdef __KLIBC__
+# include
+#endif
+#include "intprops.h"
-/* Set BUF to the expansion of PROC_SELF_FD_FORMAT, using FD and FILE
- respectively for %d and %s. If successful, return BUF if the
- result fits in BUF, dynamically allocated memory otherwise. But
- return NULL if /proc is not reliable, either because the operating
- system support is lacking or because memory is low. */
+/* Set BUF to the name of the subfile of the directory identified by
+ FD, where the subfile is named FILE. If successful, return BUF if
+ the result fits in BUF, dynamically allocated memory otherwise.
+ Return NULL (setting errno) on error. */
char *
openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
{
- static int proc_status = 0;
+ char *result = buf;
+ int dirlen;
/* Make sure the caller gets ENOENT when appropriate. */
if (!*file)
@@ -64,47 +53,82 @@ openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
return buf;
}
- if (! proc_status)
- {
- /* Set PROC_STATUS to a positive value if /proc/self/fd is
- reliable, and a negative value otherwise. Solaris 10
- /proc/self/fd mishandles "..", and any file name might expand
- to ".." after symbolic link expansion, so avoid /proc/self/fd
- if it mishandles "..". Solaris 10 has openat, but this
- problem is exhibited on code that built on Solaris 8 and
- running on Solaris 10. */
-
- int proc_self_fd = open ("/proc/self/fd",
- O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK);
- if (proc_self_fd < 0)
- proc_status = -1;
- else
- {
- /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the
- number of a file descriptor open on /proc/self/fd. On Linux,
- that name resolves to /proc/self/fd, which was opened above.
- However, on Solaris, it may resolve to /proc/self/fd/fd, which
- cannot exist, since all names in /proc/self/fd are numeric. */
- char dotdot_buf[PROC_SELF_FD_NAME_SIZE_BOUND (sizeof "../fd" - 1)];
- sprintf (dotdot_buf, PROC_SELF_FD_FORMAT, proc_self_fd, "../fd");
- proc_status = access (dotdot_buf, F_OK) ? -1 : 1;
- close (proc_self_fd);
- }
- }
-
- if (proc_status < 0)
- return NULL;
- else
- {
- size_t bufsize = PROC_SELF_FD_NAME_SIZE_BOUND (strlen (file));
- char *result = buf;
- if (OPENAT_BUFFER_SIZE < bufsize)
- {
- result = malloc (bufsize);
- if (! result)
- return NULL;
- }
- sprintf (result, PROC_SELF_FD_FORMAT, fd, file);
- return result;
- }
+#ifndef __KLIBC__
+# define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/"
+ {
+ enum {
+ PROC_SELF_FD_DIR_SIZE_BOUND
+ = (sizeof PROC_SELF_FD_FORMAT - (sizeof "%d" - 1)
+ + INT_STRLEN_BOUND (int))
+ };
+
+ static int proc_status = 0;
+ if (! proc_status)
+ {
+ /* Set PROC_STATUS to a positive value if /proc/self/fd is
+ reliable, and a negative value otherwise. Solaris 10
+ /proc/self/fd mishandles "..", and any file name might expand
+ to ".." after symbolic link expansion, so avoid /proc/self/fd
+ if it mishandles "..". Solaris 10 has openat, but this
+ problem is exhibited on code that built on Solaris 8 and
+ running on Solaris 10. */
+
+ int proc_self_fd = open ("/proc/self/fd",
+ O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK);
+ if (proc_self_fd < 0)
+ proc_status = -1;
+ else
+ {
+ /* Detect whether /proc/self/fd/%i/../fd exists, where %i is the
+ number of a file descriptor open on /proc/self/fd. On Linux,
+ that name resolves to /proc/self/fd, which was opened above.
+ However, on Solaris, it may resolve to /proc/self/fd/fd, which
+ cannot exist, since all names in /proc/self/fd are numeric. */
+ char dotdot_buf[PROC_SELF_FD_DIR_SIZE_BOUND + sizeof "../fd" - 1];
+ sprintf (dotdot_buf, PROC_SELF_FD_FORMAT "../fd", proc_self_fd);
+ proc_status = access (dotdot_buf, F_OK) ? -1 : 1;
+ close (proc_self_fd);
+ }
+ }
+
+ if (proc_status < 0)
+ return NULL;
+ else
+ {
+ size_t bufsize = PROC_SELF_FD_DIR_SIZE_BOUND + strlen (file);
+ if (OPENAT_BUFFER_SIZE < bufsize)
+ {
+ result = malloc (bufsize);
+ if (! result)
+ return NULL;
+ }
+
+ dirlen = sprintf (result, PROC_SELF_FD_FORMAT, fd);
+ }
+ }
+#else
+ /* OS/2 kLIBC provides a function to retrieve a path from a fd. */
+ {
+ char dir[_MAX_PATH];
+ size_t bufsize;
+
+ if (__libc_Back_ioFHToPath (fd, dir, sizeof dir))
+ return NULL;
+
+ dirlen = strlen (dir);
+ bufsize = dirlen + 1 + strlen (file) + 1; /* 1 for '/', 1 for null */
+ if (OPENAT_BUFFER_SIZE < bufsize)
+ {
+ result = malloc (bufsize);
+ if (! result)
+ return NULL;
+ }
+
+ strcpy (result, dir);
+ result[dirlen++] = '/';
+ }
+#endif
+
+ strcpy (result + dirlen, file);
+ return result;
}