From: Alan T. DeKok <aland@freeradius.org>
Date: Thu, 3 Oct 2024 14:29:52 +0000 (-0400)
Subject: add fr_bio_fd_reopen() API
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7bbd1fd5d1a1d3e5ae35580d31030a1c46281ba0;p=thirdparty%2Ffreeradius-server.git

add fr_bio_fd_reopen() API

so that we can re-open a file BIO
---

diff --git a/src/lib/bio/fd.h b/src/lib/bio/fd.h
index 04b2ac56dfb..d132988e5b4 100644
--- a/src/lib/bio/fd.h
+++ b/src/lib/bio/fd.h
@@ -130,3 +130,5 @@ fr_bio_fd_info_t const *fr_bio_fd_info(fr_bio_t *bio) CC_HINT(nonnull);
 int		fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg) CC_HINT(nonnull);
 
 int		fr_bio_fd_write_only(fr_bio_t *bio);
+
+int		fr_bio_fd_reopen(fr_bio_t *bio);
diff --git a/src/lib/bio/fd_open.c b/src/lib/bio/fd_open.c
index e12676d82d5..899e313a7eb 100644
--- a/src/lib/bio/fd_open.c
+++ b/src/lib/bio/fd_open.c
@@ -799,16 +799,12 @@ int fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg)
 			fd = dup(STDERR_FILENO);
 
 		} else {
-			if (!cfg->mkdir) {
-				fd = open(cfg->filename, cfg->flags, cfg->perm);
-			} else {
-				if (fr_mkdir(&fd, cfg->filename, fr_mkdir_chown, &(fr_mkdir_chown_t) {
-							.uid = cfg->uid,
-							.gid = cfg->gid,
-						}) < 0) {
-					return -1;
-				}
-			}
+			/*
+			 *	Minor hacks so that we have only _one_ source of open / mkdir
+			 */
+			my->info.socket.fd = -1;
+
+			fd = fr_bio_fd_reopen(bio);
 		}
 		if (fd < 0) {
 			fr_strerror_printf("Failed opening file %s: %s", cfg->filename, fr_syserror(errno));
@@ -966,3 +962,54 @@ int fr_bio_fd_open(fr_bio_t *bio, fr_bio_fd_config_t const *cfg)
 
 	return 0;
 }
+
+/** Reopen a file BIO
+ *
+ *  e.g. for log files.
+ */
+int fr_bio_fd_reopen(fr_bio_t *bio)
+{
+	fr_bio_fd_t *my = talloc_get_type_abort(bio, fr_bio_fd_t);
+	fr_bio_fd_config_t const *cfg = my->info.cfg;
+	int fd;
+
+	if (my->info.socket.af != AF_FILE_BIO) {
+		fr_strerror_const("Cannot reopen a non-file BIO");
+		return -1;
+	}
+
+	if (!cfg->mkdir) {
+		fd = open(cfg->filename, cfg->flags, cfg->perm);
+		if (fd < 0) {
+			fr_strerror_printf("Failed opening file %s: %s", cfg->filename, fr_syserror(errno));
+			return -1;
+		}
+
+	} else if (fr_mkdir(&fd, cfg->filename, strlen(cfg->filename), cfg->perm,
+			    fr_mkdir_chown, &(fr_mkdir_chown_t) {
+				    .uid = cfg->uid,
+				    .gid = cfg->gid,
+			    }) < 0) {
+		return -1;
+	}
+
+	/*
+	 *	We're boot-strapping, just set the new FD and return.
+	 */
+	if (my->info.socket.fd < 0) {
+		return fd;
+	}
+
+	/*
+	 *	Replace the FD rather than swapping it out with a new one.  This is potentially more
+	 *	thread-safe.
+	 */
+	if (dup2(fd, my->info.socket.fd) < 0) {
+		close(fd);
+		fr_strerror_printf("Failed reopening file - %s", fr_syserror(errno));
+		return -1;
+	}
+
+	close(fd);
+	return my->info.socket.fd;
+}