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From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH 4/9] util: Add open_in_ns() helper
Date: Thu,  5 Oct 2023 14:44:40 +1100	[thread overview]
Message-ID: <20231005034445.2015303-5-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20231005034445.2015303-1-david@gibson.dropbear.id.au>

Most of our helpers which need to enter the pasta network namespace are
quite specialised.  Add one which is rather general - it just open()s a
given file in the namespace context and returns the fd back to the main
namespace.  This will have some future uses.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 util.c | 39 +++++++++++++++++++++++++++++++++++++++
 util.h |  1 +
 2 files changed, 40 insertions(+)

diff --git a/util.c b/util.c
index a8f3b35..92ad375 100644
--- a/util.c
+++ b/util.c
@@ -364,6 +364,45 @@ bool ns_is_init(void)
 	return ret;
 }
 
+struct open_in_ns_args {
+	const struct ctx *c;
+	int fd;
+	int err;
+	const char *path;
+	int flags;
+};
+
+static int do_open_in_ns(void *arg)
+{
+	struct open_in_ns_args *a = (struct open_in_ns_args *)arg;
+
+	ns_enter(a->c);
+
+	a->fd = open(a->path, a->flags);
+	a->err = errno;
+
+	return 0;
+}
+
+/**
+ * open_in_ns() - open() within the pasta namespace
+ * @c:		Execution context
+ * @path:	Path to open
+ * @flags:	open() flags
+ *
+ * Return: fd of open()ed file or -1 on error, errno is set to indicate error
+ */
+int open_in_ns(const struct ctx *c, const char *path, int flags)
+{
+	struct open_in_ns_args arg = {
+		.c = c, .path = path, .flags = flags,
+	};
+
+	NS_CALL(do_open_in_ns, &arg);
+	errno = arg.err;
+	return arg.fd;
+}
+
 /**
  * pid_file() - Write PID to file, if requested to do so, and close it
  * @fd:		Open PID file descriptor, closed on exit, -1 to skip writing it
diff --git a/util.h b/util.h
index 9effc54..78a8fb2 100644
--- a/util.h
+++ b/util.h
@@ -219,6 +219,7 @@ int bitmap_isset(const uint8_t *map, int bit);
 char *line_read(char *buf, size_t len, int fd);
 void ns_enter(const struct ctx *c);
 bool ns_is_init(void);
+int open_in_ns(const struct ctx *c, const char *path, int flags);
 void write_pidfile(int fd, pid_t pid);
 int __daemon(int pidfile_fd, int devnull_fd);
 int fls(unsigned long x);
-- 
@@ -219,6 +219,7 @@ int bitmap_isset(const uint8_t *map, int bit);
 char *line_read(char *buf, size_t len, int fd);
 void ns_enter(const struct ctx *c);
 bool ns_is_init(void);
+int open_in_ns(const struct ctx *c, const char *path, int flags);
 void write_pidfile(int fd, pid_t pid);
 int __daemon(int pidfile_fd, int devnull_fd);
 int fls(unsigned long x);
-- 
2.41.0


  parent reply	other threads:[~2023-10-05  3:44 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-10-05  3:44 [PATCH 0/9] Clean ups to automatic port forwarding David Gibson
2023-10-05  3:44 ` [PATCH 1/9] conf: Cleaner initialisation of default forwarding modes David Gibson
2023-10-05  3:44 ` [PATCH 2/9] port_fwd: Move automatic port forwarding code to port_fwd.[ch] David Gibson
2023-10-05  3:44 ` [PATCH 3/9] port_fwd: Better parameterise procfs_scan_listen() David Gibson
2023-11-02 18:07   ` Stefano Brivio
2023-11-03  0:16     ` David Gibson
2023-10-05  3:44 ` David Gibson [this message]
2023-11-02 18:07   ` [PATCH 4/9] util: Add open_in_ns() helper Stefano Brivio
2023-11-03  0:20     ` David Gibson
2023-10-05  3:44 ` [PATCH 5/9] port_fwd: Pre-open /proc/net/* files rather than on-demand David Gibson
2023-10-05  3:44 ` [PATCH 6/9] port_fwd: Don't NS_CALL get_bound_ports() David Gibson
2023-10-05  3:44 ` [PATCH 7/9] port_fwd: Split TCP and UDP cases for get_bound_ports() David Gibson
2023-10-05  3:44 ` [PATCH 8/9] port_fwd: Move port scanning /proc fds into struct port_fwd David Gibson
2023-10-05  3:44 ` [PATCH 9/9] port_fwd: Simplify get_bound_ports_*() to port_fwd_scan_*() David Gibson

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