From: ZmnSCPxj <ZmnSCPxj@protonmail.com>
To: "ccan@lists.ozlabs.org" <ccan@lists.ozlabs.org>
Subject: [ccan] [PATCH 2/2] pipecmd: Use closefrom instead of iterating directly.
Date: Mon, 18 Oct 2021 07:56:05 +0000 [thread overview]
Message-ID: <NQALm57droQyV-k0BgF75D181ZT3z8Nv2b-x-eqNu73uLu8HCV1n8w_MGWqJHP2HoUpIaMn0FSvk9_sPSDMiI0jlhLB2cS-k80ysYIw-I44=@protonmail.com> (raw)
From b48091be33010782e0b82245f3518c7b4cc94b9c Mon Sep 17 00:00:00 2001
From: ZmnSCPxj jxPCSnmZ <ZmnSCPxj@protonmail.com>
Date: Mon, 18 Oct 2021 15:50:31 +0800
Subject: [PATCH 2/2] pipecmd: Use closefrom instead of iterating directly.
Signed-off-by: ZmnSCPxj jxPCSnmZ <ZmnSCPxj@protonmail.com>
---
ccan/pipecmd/_info | 1 +
ccan/pipecmd/pipecmd.c | 19 +++++++++++++++----
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/ccan/pipecmd/_info b/ccan/pipecmd/_info
index 8c49511a..824f22e3 100644
--- a/ccan/pipecmd/_info
+++ b/ccan/pipecmd/_info
@@ -51,6 +51,7 @@ int main(int argc, char *argv[])
return 1;
if (strcmp(argv[1], "depends") == 0) {
+ printf("ccan/closefrom\n");
printf("ccan/noerr\n");
return 0;
}
diff --git a/ccan/pipecmd/pipecmd.c b/ccan/pipecmd/pipecmd.c
index 56cb67b6..0090275b 100644
--- a/ccan/pipecmd/pipecmd.c
+++ b/ccan/pipecmd/pipecmd.c
@@ -1,4 +1,5 @@
/* CC0 license (public domain) - see LICENSE file for details */
+#include <ccan/closefrom/closefrom.h>
#include <ccan/pipecmd/pipecmd.h>
#include <ccan/noerr/noerr.h>
#include <stdlib.h>
@@ -139,11 +140,21 @@ pid_t pipecmdarr(int *fd_tochild, int *fd_fromchild, int *fd_errfromchild,
close(errfromchild[1]);
}
+ /* Map execfail[1] to fd 3. */
+ if (execfail[1] != 3) {
+ if (dup2(execfail[1], 3) == -1)
+ goto child_errno_fail;
+ /* CLOEXEC is not shared by dup2, so copy the flags
+ * from execfail[1] to 3.
+ */
+ if (fcntl(3, F_SETFD, fcntl(execfail[1], F_GETFD)) < 0)
+ goto child_errno_fail;
+ close(execfail[1]);
+ execfail[1] = 3;
+ }
+
/* Make (fairly!) sure all other fds are closed. */
- int max = sysconf(_SC_OPEN_MAX);
- for (i = 3; i < max; i++)
- if (i != execfail[1])
- close(i);
+ closefrom(4);
execvp(arr[0], arr);
--
2.33.0
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reply other threads:[~2022-09-01 7:02 UTC|newest]
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