lineread: Use ssize_t for line lengths

Functions and structures in lineread.c use plain int to record and report
the length of lines we receive.  This means we truncate the result from
read(2) in some circumstances.  Use ssize_t to avoid that.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

3 files changed, 9 insertions, 10 deletions

diff --git a/conf.c b/conf.c
index fdeb9db..3998bfa 100644
--- a/conf.c
+++ b/conf.c
@@ -401,9 +401,9 @@ static void get_dns(struct ctx *c)
 	struct fqdn *s = c->dns_search;
 	struct lineread resolvconf;
 	unsigned int added = 0;
+	ssize_t line_len;
 	char *line, *end;
 	const char *p;
-	int line_len;
 
 	dns4_set = !c->ifi4 || !IN4_IS_ADDR_UNSPECIFIED(dns4);
 	dns6_set = !c->ifi6 || !IN6_IS_ADDR_UNSPECIFIED(dns6);
diff --git a/lineread.c b/lineread.c
index d631da4..0387f4a 100644
--- a/lineread.c
+++ b/lineread.c
@@ -39,13 +39,11 @@ void lineread_init(struct lineread *lr, int fd)
  *
  * Return: length of line in bytes, -1 if no line was found
  */
-static int peek_line(struct lineread *lr, bool eof)
+static ssize_t peek_line(struct lineread *lr, bool eof)
 {
 	char *nl;
 
 	/* Sanity checks (which also document invariants) */
-	ASSERT(lr->count >= 0);
-	ASSERT(lr->next_line >= 0);
 	ASSERT(lr->next_line + lr->count >= lr->next_line);
 	ASSERT(lr->next_line + lr->count <= LINEREAD_BUFFER_SIZE);
 
@@ -74,13 +72,13 @@ static int peek_line(struct lineread *lr, bool eof)
  *
  * Return:	Length of line read on success, 0 on EOF, negative on error
  */
-int lineread_get(struct lineread *lr, char **line)
+ssize_t lineread_get(struct lineread *lr, char **line)
 {
 	bool eof = false;
-	int line_len;
+	ssize_t line_len;
 
 	while ((line_len = peek_line(lr, eof)) < 0) {
-		int rc;
+		ssize_t rc;
 
 		if ((lr->next_line + lr->count) == LINEREAD_BUFFER_SIZE) {
 			/* No space at end */
diff --git a/lineread.h b/lineread.h
index af86418..9203e28 100644
--- a/lineread.h
+++ b/lineread.h
@@ -18,14 +18,15 @@
  * @buf:	Buffer storing data read from file.
  */
 struct lineread {
-	int fd; int next_line;
-	int count;
+	int fd;
+	ssize_t next_line;
+	ssize_t count;
 
 	/* One extra byte for possible trailing \0 */
 	char buf[LINEREAD_BUFFER_SIZE+1];
 };
 
 void lineread_init(struct lineread *lr, int fd);
-int lineread_get(struct lineread *lr, char **line);
+ssize_t lineread_get(struct lineread *lr, char **line);
 
 #endif /* _LINEREAD_H */