From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julien Fortin Subject: [PATCH iproute2 v3] ip: ip_print: if no json obj is initialized default fp is stdout Date: Wed, 20 Sep 2017 18:23:56 -0700 Message-ID: <20170921012356.46451-1-julien@cumulusnetworks.com> Cc: roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com, dsa@cumulusnetworks.com, Julien Fortin To: netdev@vger.kernel.org Return-path: Received: from mail-pg0-f43.google.com ([74.125.83.43]:51501 "EHLO mail-pg0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751000AbdIUBX7 (ORCPT ); Wed, 20 Sep 2017 21:23:59 -0400 Received: by mail-pg0-f43.google.com with SMTP id k193so2658725pgc.8 for ; Wed, 20 Sep 2017 18:23:59 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Julien Fortin The ip monitor didn't call `new_json_obj` (even for in non json context), so the static FILE* _fp variable wasn't initialized, thus raising a SIGSEGV in ipaddress.c. This patch should fix this issue for good, new paths won't have to call `new_json_obj`. $ ip -t mon label link fmt=fmt@entry=0x45460d "%d: ", value=) at ip_print.c:132 #3 0x000000000040ccd2 in print_int (value=, fmt=0x45460d "%d: ", key=0x4545fc "ifindex", t=PRINT_ANY) at ip_common.h:189 #4 print_linkinfo (who=, n=0x7fffffffa380, arg=0x7ffff77a82a0 <_IO_2_1_stdout_>) at ipaddress.c:1107 #5 0x0000000000422e13 in accept_msg (who=0x7fffffff8320, ctrl=0x7fffffff8310, n=0x7fffffffa380, arg=0x7ffff77a82a0 <_IO_2_1_stdout_>) at ipmonitor.c:89 #6 0x000000000044c58f in rtnl_listen (rtnl=0x672160 , handler=handler@entry=0x422c70 , jarg=0x7ffff77a82a0 <_IO_2_1_stdout_>) at libnetlink.c:761 #7 0x00000000004233db in do_ipmonitor (argc=, argv=0x7fffffffe5a0) at ipmonitor.c:310 #8 0x0000000000408f74 in do_cmd (argv0=0x7fffffffe7f5 "mon", argc=3, argv=0x7fffffffe588) at ip.c:116 #9 0x0000000000408a94 in main (argc=4, argv=0x7fffffffe580) at ip.c:311 Traceback can be seen when running the following command in a new terminal. $ ip link add dev br0 type bridge Fixes: 6377572f ("ip: ip_print: add new API to print JSON or regular format output") Reported-by: David Ahern Reviewed-by: David Ahern Signed-off-by: Julien Fortin --- ip/ip_print.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/ip/ip_print.c b/ip/ip_print.c index 4cd6a0bc..7eb4c6da 100644 --- a/ip/ip_print.c +++ b/ip/ip_print.c @@ -23,6 +23,11 @@ static FILE *_fp; #define _IS_JSON_CONTEXT(type) ((type & PRINT_JSON || type & PRINT_ANY) && _jw) #define _IS_FP_CONTEXT(type) (!_jw && (type & PRINT_FP || type & PRINT_ANY)) +static inline FILE *_get_fp(void) +{ + return _fp ? _fp : stdout; +}; + void new_json_obj(int json, FILE *fp) { if (json) { @@ -91,7 +96,7 @@ void open_json_array(enum output_type type, const char *str) jsonw_name(_jw, str); jsonw_start_array(_jw); } else if (_IS_FP_CONTEXT(type)) { - fprintf(_fp, "%s", str); + fprintf(_get_fp(), "%s", str); } } @@ -105,7 +110,7 @@ void close_json_array(enum output_type type, const char *str) jsonw_end_array(_jw); jsonw_pretty(_jw, true); } else if (_IS_FP_CONTEXT(type)) { - fprintf(_fp, "%s", str); + fprintf(_get_fp(), "%s", str); } } @@ -126,7 +131,7 @@ void close_json_array(enum output_type type, const char *str) else \ jsonw_##type_name##_field(_jw, key, value); \ } else if (_IS_FP_CONTEXT(t)) { \ - color_fprintf(_fp, color, fmt, value); \ + color_fprintf(_get_fp(), color, fmt, value); \ } \ } _PRINT_FUNC(int, int); @@ -149,7 +154,7 @@ void print_color_string(enum output_type type, else jsonw_string_field(_jw, key, value); } else if (_IS_FP_CONTEXT(type)) { - color_fprintf(_fp, color, fmt, value); + color_fprintf(_get_fp(), color, fmt, value); } } @@ -170,7 +175,7 @@ void print_color_bool(enum output_type type, else jsonw_bool(_jw, value); } else if (_IS_FP_CONTEXT(type)) { - color_fprintf(_fp, color, fmt, value ? "true" : "false"); + color_fprintf(_get_fp(), color, fmt, value ? "true" : "false"); } } @@ -189,7 +194,7 @@ void print_color_0xhex(enum output_type type, snprintf(b1, sizeof(b1), "%#x", hex); print_string(PRINT_JSON, key, NULL, b1); } else if (_IS_FP_CONTEXT(type)) { - color_fprintf(_fp, color, fmt, hex); + color_fprintf(_get_fp(), color, fmt, hex); } } @@ -208,7 +213,7 @@ void print_color_hex(enum output_type type, else jsonw_string(_jw, b1); } else if (_IS_FP_CONTEXT(type)) { - color_fprintf(_fp, color, fmt, hex); + color_fprintf(_get_fp(), color, fmt, hex); } } @@ -228,6 +233,6 @@ void print_color_null(enum output_type type, else jsonw_null(_jw); } else if (_IS_FP_CONTEXT(type)) { - color_fprintf(_fp, color, fmt, value); + color_fprintf(_get_fp(), color, fmt, value); } } -- 2.14.1