diff options
author | Pablo Neira Ayuso <pablo@netfilter.org> | 2014-04-28 11:23:26 +0200 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2014-04-28 12:59:00 +0200 |
commit | bb91cd49ae8d4a471b9c4c0c8ab86bb3940f7d69 (patch) | |
tree | 71673c44782ff85e01ab783a59a5764abe803858 /src | |
parent | 3448b27ad573982c4e0e7ab2cc3b34edac3eea82 (diff) |
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 <pablo@netfilter.org>
Diffstat (limited to 'src')
-rw-r--r-- | src/internal.h | 11 | ||||
-rw-r--r-- | src/libnetfilter_acct.c | 21 |
2 files changed, 19 insertions, 13 deletions
diff --git a/src/internal.h b/src/internal.h index 2106401..f0cc2e1 100644 --- a/src/internal.h +++ b/src/internal.h @@ -21,4 +21,15 @@ # endif #endif +#define SNPRINTF_CHECK(ret, rem, offset, len) \ +do { \ + if (ret < 0) \ + return ret; \ + len += ret; \ + if (ret > rem) \ + ret = rem; \ + offset += ret; \ + rem -= ret; \ +} while (0) + #endif 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) \ |