[dpdk-dev] [PATCH] librte_cmdline: FreeBSD Fix oveflow when size of command result structure is greater than BUFSIZ

[Alan Carew]

When using test-pmd with flow director in FreeBSD, the application will
segfault/Bus error while parsing the command-line. This is due to how
each commands result structure is represented during parsing, where the offsets
for each tokens value is stored in a character array(char result_buf[BUFSIZ])
in cmdline_parse()(./lib/librte_cmdline/cmdline_parse.c).

The overflow occurs where BUFSIZ is less than the size of a commands result
structure, in this case "struct cmd_pkt_filter_result"
(app/test-pmd/cmdline.c) is 1088 bytes and BUFSIZ on FreeBSD is 1024 bytes as
opposed to 8192 bytes on Linux.

This patch removes the OS dependency on BUFSIZ and defines and uses a
library #define CMDLINE_PARSE_RESULT_BUFSIZE 8192

The problem can be reproduced by running test-pmd on FreeBSD:
./testpmd -c 0x3 -n 4 -- -i --portmask=0x3 --pkt-filter-mode=perfect
And adding a filter:
add_perfect_filter 0 udp src 192.168.0.0 1024 dst 192.168.0.0 1024 flexbytes
0x800 vlan 0 queue 0 soft 0x17

Signed-off-by: Alan Carew <alan.carew at intel.com>
---
 lib/librte_cmdline/cmdline_parse.c | 2 +-
 lib/librte_cmdline/cmdline_parse.h | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/librte_cmdline/cmdline_parse.c b/lib/librte_cmdline/cmdline_parse.c
index 940480d..29f1afd 100644
--- a/lib/librte_cmdline/cmdline_parse.c
+++ b/lib/librte_cmdline/cmdline_parse.c
@@ -219,7 +219,7 @@ cmdline_parse(struct cmdline *cl, const char * buf)
 	unsigned int inst_num=0;
 	cmdline_parse_inst_t *inst;
 	const char *curbuf;
-	char result_buf[BUFSIZ];
+	char result_buf[CMDLINE_PARSE_RESULT_BUFSIZE];
 	void (*f)(void *, struct cmdline *, void *) = NULL;
 	void *data = NULL;
 	int comment = 0;
diff --git a/lib/librte_cmdline/cmdline_parse.h b/lib/librte_cmdline/cmdline_parse.h
index f18836d..dae53ba 100644
--- a/lib/librte_cmdline/cmdline_parse.h
+++ b/lib/librte_cmdline/cmdline_parse.h
@@ -80,6 +80,9 @@ extern "C" {
 #define CMDLINE_PARSE_COMPLETE_AGAIN    1
 #define CMDLINE_PARSE_COMPLETED_BUFFER  2
 
+/* maximum buffer size for parsed result */
+#define CMDLINE_PARSE_RESULT_BUFSIZE 8192
+
 /**
  * Stores a pointer to the ops struct, and the offset: the place to
  * write the parsed result in the destination structure.
-- 
1.9.3