From 1bb714b95e298bc60a839b6daaac60179540b7d4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Barnab=C3=A1s=20P=C5=91cze?= <pobrn@protonmail.com>
Date: Mon, 3 Jul 2023 19:02:18 +0200
Subject: [PATCH] pipewire: utils: make_random(): do not use errno

The function already returns `ssize_t`, so do not use `errno`
to communicate the reason for failure, instead, return the
negative errno.

`pw_getrandom()` was inconsistent in this regard because
sometimes it simply returned a negative errno without
setting `errno`. This change fixes that as well.
---
 src/modules/module-raop-sink.c | 25 ++++++++++++++-----------
 src/pipewire/utils.c           | 20 ++++++++++++--------
 2 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/src/modules/module-raop-sink.c b/src/modules/module-raop-sink.c
index a54f6d5d6..be03e3726 100644
--- a/src/modules/module-raop-sink.c
+++ b/src/modules/module-raop-sink.c
@@ -972,6 +972,7 @@ static int rtsp_setup_reply(void *data, int status, const struct spa_dict *heade
 	size_t len;
 	uint64_t ntp;
 	uint16_t control_port, timing_port;
+	int res;
 
 	pw_log_info("reply %d", status);
 
@@ -1003,9 +1004,9 @@ static int rtsp_setup_reply(void *data, int status, const struct spa_dict *heade
 		return 0;
 	}
 
-	if (pw_getrandom(&impl->seq, sizeof(impl->seq), 0) < 0 ||
-	    pw_getrandom(&impl->rtptime, sizeof(impl->rtptime), 0) <  0) {
-		pw_log_error("error generating random seq and rtptime: %m");
+	if ((res = pw_getrandom(&impl->seq, sizeof(impl->seq), 0)) < 0 ||
+	    (res = pw_getrandom(&impl->rtptime, sizeof(impl->rtptime), 0)) <  0) {
+		pw_log_error("error generating random seq and rtptime: %s", spa_strerror(res));
 		return 0;
 	}
 
@@ -1258,9 +1259,9 @@ static int rtsp_do_announce(struct impl *impl)
 		break;
 
 	case CRYPTO_RSA:
-		if (pw_getrandom(impl->key, sizeof(impl->key), 0) < 0 ||
-		    pw_getrandom(impl->iv, sizeof(impl->iv), 0) < 0)
-			return -errno;
+		if ((res = pw_getrandom(impl->key, sizeof(impl->key), 0)) < 0 ||
+		    (res = pw_getrandom(impl->iv, sizeof(impl->iv), 0)) < 0)
+			return res;
 
 		rsa_len = rsa_encrypt(impl->key, 16, rsakey);
 		if (rsa_len < 0)
@@ -1420,14 +1421,15 @@ static void rtsp_connected(void *data)
 	uint32_t sci[2];
 	uint8_t rac[16];
 	char sac[16*4];
+	int res;
 
 	pw_log_info("connected");
 
 	impl->connected = true;
 
-	if (pw_getrandom(sci, sizeof(sci), 0) < 0 ||
-	    pw_getrandom(rac, sizeof(rac), 0) < 0) {
-		pw_log_error("error generating random data: %m");
+	if ((res = pw_getrandom(sci, sizeof(sci), 0)) < 0 ||
+	    (res = pw_getrandom(rac, sizeof(rac), 0)) < 0) {
+		pw_log_error("error generating random data: %s", spa_strerror(res));
 		return;
 	}
 
@@ -1533,6 +1535,7 @@ static int rtsp_do_connect(struct impl *impl)
 {
 	const char *hostname, *port;
 	uint32_t session_id;
+	int res;
 
 	if (impl->connected) {
 		if (!impl->ready)
@@ -1545,8 +1548,8 @@ static int rtsp_do_connect(struct impl *impl)
 	if (hostname == NULL || port == NULL)
 		return -EINVAL;
 
-	if (pw_getrandom(&session_id, sizeof(session_id), 0) < 0)
-		return -errno;
+	if ((res = pw_getrandom(&session_id, sizeof(session_id), 0)) < 0)
+		return res;
 
 	spa_scnprintf(impl->session_id, sizeof(impl->session_id), "%u", session_id);
 
diff --git a/src/pipewire/utils.c b/src/pipewire/utils.c
index 93170e8c2..263cee1ad 100644
--- a/src/pipewire/utils.c
+++ b/src/pipewire/utils.c
@@ -158,21 +158,25 @@ char *pw_strip(char *str, const char *whitespace)
 static inline ssize_t make_random(void *buf, size_t buflen, unsigned int flags)
 {
 	ssize_t bytes;
-	int read_errno;
 
 #ifdef HAVE_GETRANDOM
 	bytes = getrandom(buf, buflen, flags);
-	if (!(bytes == -1 && errno == ENOSYS))
+	if (bytes < 0)
+		bytes = -errno;
+	if (bytes != -ENOSYS)
 		return bytes;
 #endif
 
 	int fd = open("/dev/urandom", O_CLOEXEC);
 	if (fd < 0)
-		return -1;
+		return -errno;
+
 	bytes = read(fd, buf, buflen);
-	read_errno = errno;
+	if (bytes < 0)
+		bytes = -errno;
+
 	close(fd);
-	errno = read_errno;
+
 	return bytes;
 }
 
@@ -190,9 +194,9 @@ ssize_t pw_getrandom(void *buf, size_t buflen, unsigned int flags)
 	ssize_t res;
 	do {
 		res = make_random(buf, buflen, flags);
-	} while ((res == -1) && (errno == EINTR));
-	if (res == -1)
-		return -errno;
+	} while (res == -EINTR);
+	if (res < 0)
+		return res;
 	if ((size_t)res != buflen)
 		return -ENODATA;
 	return res;