1 files changed, 79 insertions, 0 deletions
diff --git a/lib/iolog/iolog_read.c b/lib/iolog/iolog_read.c
new file mode 100644
index 0000000..013ecaa
--- /dev/null
+++ b/lib/iolog/iolog_read.c
@@ -0,0 +1,79 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2009-2021 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include <compat/stdbool.h>
+#endif
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include <time.h>
+
+#include <sudo_compat.h>
+#include <sudo_debug.h>
+#include <sudo_iolog.h>
+
+/*
+ * Read from a (possibly compressed) I/O log file.
+ */
+ssize_t
+iolog_read(struct iolog_file *iol, void *buf, size_t nbytes,
+    const char **errstr)
+{
+    ssize_t nread;
+    debug_decl(iolog_read, SUDO_DEBUG_UTIL);
+
+    if (nbytes > UINT_MAX || nbytes > SSIZE_MAX) { // -V590
+	errno = EINVAL;
+	if (errstr != NULL)
+	    *errstr = strerror(errno);
+	debug_return_ssize_t(-1);
+    }
+
+#ifdef HAVE_ZLIB_H
+    if (iol->compressed) {
+	if ((nread = gzread(iol->fd.g, buf, (unsigned int)nbytes)) == -1) {
+	    if (errstr != NULL) {
+		int errnum;
+		*errstr = gzerror(iol->fd.g, &errnum);
+		if (errnum == Z_ERRNO)
+		    *errstr = strerror(errno);
+	    }
+	}
+    } else
+#endif
+    {
+	nread = (ssize_t)fread(buf, 1, nbytes, iol->fd.f);
+	if (nread <= 0 && ferror(iol->fd.f)) {
+	    nread = -1;
+	    if (errstr != NULL)
+		*errstr = strerror(errno);
+	}
+    }
+    debug_return_ssize_t(nread);
+}