From bb91cd49ae8d4a471b9c4c0c8ab86bb3940f7d69 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 28 Apr 2014 11:23:26 +0200 Subject: src: fix broken output handling In 948fa3b ("Extend accounting capabilities to support quotas"), the error handling of snprintf is incorrect since this function may return -1 on error. Add a new SNPRINTF_CHECK() macro to offload the complicated handling of snprintf. Signed-off-by: Pablo Neira Ayuso --- src/libnetfilter_acct.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) (limited to 'src/libnetfilter_acct.c') diff --git a/src/libnetfilter_acct.c b/src/libnetfilter_acct.c index 0c1a758..7f539b6 100644 --- a/src/libnetfilter_acct.c +++ b/src/libnetfilter_acct.c @@ -256,42 +256,37 @@ static int nfacct_snprintf_plain(char *buf, size_t rem, struct nfacct *nfacct, uint16_t flags) { - int ret, temp; - char *walking_buf; - - temp = rem; - walking_buf = buf; + int ret, offset = 0, len = 0; if (flags & NFACCT_SNPRINTF_F_FULL) { - ret = snprintf(walking_buf, temp, + ret = snprintf(buf, rem, "{ pkts = %.20"PRIu64", bytes = %.20"PRIu64"", nfacct_attr_get_u64(nfacct, NFACCT_ATTR_PKTS), nfacct_attr_get_u64(nfacct, NFACCT_ATTR_BYTES)); + SNPRINTF_CHECK(ret, rem, offset, len); if (nfacct->flags) { uint32_t mode; mode = nfacct_attr_get_u64(nfacct, NFACCT_ATTR_FLAGS); - walking_buf += ret; - temp -= ret; - ret = snprintf(walking_buf, temp, + ret = snprintf(buf + offset, rem, ", quota = %.20"PRIu64", mode = %s", nfacct_attr_get_u64(nfacct, NFACCT_ATTR_QUOTA), mode == NFACCT_F_QUOTA_BYTES ? "byte" : "packet"); + SNPRINTF_CHECK(ret, rem, offset, len); } - walking_buf += ret; - temp -= ret; - ret = snprintf(walking_buf, temp, " } = %s;", + ret = snprintf(buf + offset, rem, " } = %s;", nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME)); } else { ret = snprintf(buf, rem, "%s\n", nfacct_attr_get_str(nfacct, NFACCT_ATTR_NAME)); } + SNPRINTF_CHECK(ret, rem, offset, len); - return ret; + return len; } #define BUFFER_SIZE(ret, size, rem, offset) \ -- cgit v1.2.3