[iptables PATCH 2/2] nfnl_osf: Improve error handling

[Phil Sutter <phil@nwl.cc>]

For some error cases, no log message was created - hence apart from the
return code there was no indication of failing execution.

When loading a line fails, don't abort but continue with the remaining
file contents. The current pf.os file in this repository serves as
proof-of-concept: Loading all entries succeeds, but when deleting, lines
700, 701 and 704 return ENOENT. Not continuing means the remaining
entries are not cleared.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 utils/nfnl_osf.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/utils/nfnl_osf.c b/utils/nfnl_osf.c
index 922d90ac135b7..8a74423fc8428 100644
--- a/utils/nfnl_osf.c
+++ b/utils/nfnl_osf.c
@@ -392,7 +392,7 @@ static int osf_load_line(char *buffer, int len, int del)
 static int osf_load_entries(char *path, int del)
 {
 	FILE *inf;
-	int err = 0;
+	int err = 0, lineno = 0;
 	char buf[1024];
 
 	inf = fopen(path, "r");
@@ -402,7 +402,9 @@ static int osf_load_entries(char *path, int del)
 	}
 
 	while(fgets(buf, sizeof(buf), inf)) {
-		int len;
+		int len, rc;
+
+		lineno++;
 
 		if (buf[0] == '#' || buf[0] == '\n' || buf[0] == '\r')
 			continue;
@@ -414,9 +416,11 @@ static int osf_load_entries(char *path, int del)
 
 		buf[len] = '\0';
 
-		err = osf_load_line(buf, len, del);
-		if (err)
-			break;
+		rc = osf_load_line(buf, len, del);
+		if (rc) {
+			ulog_err("Failed to load line %d", lineno);
+			err = rc;
+		}
 
 		memset(buf, 0, sizeof(buf));
 	}
@@ -448,6 +452,7 @@ int main(int argc, char *argv[])
 
 	if (!fingerprints) {
 		err = -ENOENT;
+		ulog_err("Missing fingerprints file argument");
 		goto err_out_exit;
 	}
 
-- 
2.25.1