lsfd: (refactor) make call_with_foreign_fd reusable

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/lsfd-cmd/Makemodule.am b/lsfd-cmd/Makemodule.am
index 0f96ce14750ddb44eea1a7a961c389786ee786a3..4674cff9ca051dfc5d33b4245cb27872eeb2eb4f 100644 (file)
--- a/lsfd-cmd/Makemodule.am
+++ b/lsfd-cmd/Makemodule.am
@@ -20,7 +20,8 @@ lsfd_SOURCES = \
        lsfd-cmd/unkn.c \
        lsfd-cmd/fifo.c \
        lsfd-cmd/pidfd.h \
-       lsfd-cmd/pidfd.c
+       lsfd-cmd/pidfd.c \
+       lsfd-cmd/util.c
 lsfd_LDADD = $(LDADD) $(MQ_LIBS) libsmartcols.la libcommon.la
 lsfd_CFLAGS = $(AM_CFLAGS) -I$(ul_libsmartcols_incdir)
 endif

diff --git a/lsfd-cmd/cdev.c b/lsfd-cmd/cdev.c
index 322e38b4a97db01951ab23cc695d6610d652924f..989ffa48125fd74e678f6734918b4f168cf65c55 100644 (file)
--- a/lsfd-cmd/cdev.c
+++ b/lsfd-cmd/cdev.c
@@ -466,28 +466,6 @@ static int cdev_tun_handle_fdinfo(struct cdev *cdev, const char *key, const char
 }
 
 #ifdef TUNGETDEVNETNS
-static int call_with_foreign_fd(pid_t target_pid, int target_fd,
-                               int (*fn)(int, void*), void *data)
-{
-       int pidfd, tfd, r;
-
-       pidfd = pidfd_open(target_pid, 0);
-       if (pidfd < 0)
-               return pidfd;
-
-       tfd = pidfd_getfd(pidfd, target_fd, 0);
-       if (tfd < 0) {
-               close(pidfd);
-               return tfd;
-       }
-
-       r = fn(tfd, data);
-
-       close(tfd);
-       close(pidfd);
-       return r;
-}
-
 static int cdev_tun_get_devnetns(int tfd, void *data)
 {
        struct tundata *tundata = data;

diff --git a/lsfd-cmd/lsfd.h b/lsfd-cmd/lsfd.h
index 626027a4a7adb24ab4ae9dcaee9c24b6211df163..553546d8b5fd8160eae584a28fa21e870da04bde 100644 (file)
--- a/lsfd-cmd/lsfd.h
+++ b/lsfd-cmd/lsfd.h
@@ -338,4 +338,10 @@ bool is_multiplexed_by_eventpoll(int fd, struct list_head *eventpolls);
  */
 bool is_pidfs_dev(dev_t dev);
 
+/*
+ * Utility
+ */
+int call_with_foreign_fd(pid_t target_pid, int target_fd,
+                        int (*fn)(int, void*), void *data);
+
 #endif /* UTIL_LINUX_LSFD_H */

diff --git a/lsfd-cmd/meson.build b/lsfd-cmd/meson.build
index 856d5cdd0594620a83febf634c804a3f777a5c74..f10ca1a41747295e18c07caefcc1c7e8710020f3 100644 (file)
--- a/lsfd-cmd/meson.build
+++ b/lsfd-cmd/meson.build
@@ -12,6 +12,7 @@ lsfd_sources = files (
   'unkn.c',
   'fifo.c',
   'pidfd.c',
+  'util.c',
 )
 
 lsfd_manadocs = files('lsfd.1.adoc')

diff --git a/lsfd-cmd/sock-xinfo.c b/lsfd-cmd/sock-xinfo.c
index 7e6ca0cf89e105ecc21ed705bad72684e93aa445..d31067009964be3cae94c18562aa59a35f949991 100644 (file)
--- a/lsfd-cmd/sock-xinfo.c
+++ b/lsfd-cmd/sock-xinfo.c
@@ -231,24 +231,16 @@ void load_sock_xinfo(struct path_cxt *pc, const char *name, ino_t netns)
        }
 }
 
-void load_fdsk_xinfo(struct proc *proc, int fd)
+static int load_fdsk_xinfo_cb(int sk, void *data __attribute__((__unused__)))
 {
-       int pidfd, sk, nsfd;
+       int nsfd;
        struct netns *nsobj;
        struct stat sb;
-
-       /* This is additional/extra information, ignoring failures. */
-       pidfd = pidfd_open(proc->pid, 0);
-       if (pidfd < 0)
-               return;
-
-       sk = pidfd_getfd(pidfd, fd, 0);
-       if (sk < 0)
-               goto out_pidfd;
+       int r = -1;
 
        nsfd = ioctl(sk, SIOCGSKNS);
        if (nsfd < 0)
-               goto out_sk;
+               return nsfd;
 
        if (fstat(nsfd, &sb) < 0)
                goto out_nsfd;
@@ -256,15 +248,20 @@ void load_fdsk_xinfo(struct proc *proc, int fd)
        if (is_sock_xinfo_loaded(sb.st_ino))
                goto out_nsfd;
 
+       r = 0;
        nsobj = mark_sock_xinfo_loaded(sb.st_ino);
        load_sock_xinfo_with_fd(nsfd, nsobj);
 
 out_nsfd:
        close(nsfd);
-out_sk:
-       close(sk);
-out_pidfd:
-       close(pidfd);
+       return r;
+}
+
+void load_fdsk_xinfo(struct proc *proc, int fd)
+{
+       call_with_foreign_fd(proc->pid, fd,
+                            load_fdsk_xinfo_cb, NULL);
+
 }
 
 void initialize_sock_xinfos(void)

diff --git a/lsfd-cmd/util.c b/lsfd-cmd/util.c
new file mode 100644 (file)
index 0000000..f3e3a72
--- /dev/null
+++ b/lsfd-cmd/util.c
@@ -0,0 +1,52 @@
+/*
+ * util.c - utilities used in lsfd
+ *
+ * Copyright (C) 2021-2026 Red Hat, Inc. All rights reserved.
+ * Written by Masatake YAMATO <yamato@redhat.com>
+ *
+ * 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
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * 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, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+#include "lsfd.h"              /* prototype decl for call_with_foreign_fd */
+#include "pidfd-utils.h"
+
+static int call_with_foreign_fd_via_pidfd(int pidfd, int target_fd,
+                                         int (*fn)(int, void*), void *data)
+{
+       int tfd, r;
+
+       tfd = pidfd_getfd(pidfd, target_fd, 0);
+       if (tfd < 0)
+               return tfd;
+
+       r = fn(tfd, data);
+
+       close(tfd);
+       return r;
+}
+
+int call_with_foreign_fd(pid_t target_pid, int target_fd,
+                        int (*fn)(int, void*), void *data)
+{
+       int pidfd, r;
+
+       pidfd = pidfd_open(target_pid, 0);
+       if (pidfd < 0)
+               return pidfd;
+
+       r = call_with_foreign_fd_via_pidfd(pidfd, target_fd, fn, data);
+
+       close(pidfd);
+       return r;
+}