musl, as of 1.2.5, and glibc < 2.34 don't ship a (trivial)
close_range() implementation. This will probably be added to musl
soon, by the way:
https://www.openwall.com/lists/musl/2024/08/01/9
Add a weakly-aliased implementation, if it's supported by the kernel.
If it's not supported (< 5.9), use a no-op fallback. Looping over 2^31
file descriptors calling close() on them is probably not a good idea.
Reported-by: lemmi
Signed-off-by: Stefano Brivio
---
util.h | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)
diff --git a/util.h b/util.h
index cb4d181..9c95dcd 100644
--- a/util.h
+++ b/util.h
@@ -14,6 +14,9 @@
#include
#include
#include
+#include
+#include
+#include
#include "log.h"
@@ -160,6 +163,25 @@ struct ctx;
/* cppcheck-suppress funcArgNamesDifferent */
__attribute__ ((weak)) int ffsl(long int i) { return __builtin_ffsl(i); }
+
+#ifdef CLOSE_RANGE_UNSHARE /* Linux kernel >= 5.9 */
+/* glibc < 2.34 and musl as of 1.2.5 need these */
+#ifndef SYS_close_range
+#define SYS_close_range 436
+#endif
+__attribute__ ((weak))
+/* cppcheck-suppress funcArgNamesDifferent */
+int close_range(unsigned int first, unsigned int last, int flags) {
+ return syscall(SYS_close_range, first, last, flags);
+}
+#else
+/* No reasonable fallback option */
+/* cppcheck-suppress funcArgNamesDifferent */
+int close_range(unsigned int first, unsigned int last, int flags) {
+ return 0;
+}
+#endif
+
int sock_l4_sa(const struct ctx *c, enum epoll_type type,
const void *sa, socklen_t sl,
const char *ifname, bool v6only, uint32_t data);
--
2.43.0