[PATCH] lib: fwts_log_json: do more json object out of memory checking
Keng-Yu Lin
kengyu at canonical.com
Tue Jul 3 05:48:17 UTC 2012
On Thu, Jun 28, 2012 at 9:22 PM, Colin King <colin.king at canonical.com> wrote:
> From: Colin Ian King <colin.king at canonical.com>
>
> The current json logging back-end is a bit sloppy because it
> neglects to check for any out of memory conditions when json
> objects are being created. So add these checks and terminate
> with some form of understandable error message on a heap failure.
>
> Signed-off-by: Colin Ian King <colin.king at canonical.com>
> ---
> src/lib/src/fwts_log_json.c | 77 +++++++++++++++++++++++++++++++++----------
> 1 file changed, 60 insertions(+), 17 deletions(-)
>
> diff --git a/src/lib/src/fwts_log_json.c b/src/lib/src/fwts_log_json.c
> index 75383a5..9afb74e 100644
> --- a/src/lib/src/fwts_log_json.c
> +++ b/src/lib/src/fwts_log_json.c
> @@ -40,7 +40,17 @@ static fwts_log_json_stack_t json_stack[MAX_JSON_STACK];
> static int json_stack_index = 0;
>
> /*
> - * fwts_log_printf_son()
> + * fwts_log_out_of_memory_json()
> + * handle out of memory from json objects
> + */
> +static void fwts_log_out_of_memory_json(void)
> +{
> + fprintf(stderr, "Out of memory allocating a json object.\n");
> + exit(EXIT_FAILURE);
> +}
> +
> +/*
> + * fwts_log_printf_json()
> * print to a log
> */
> static int fwts_log_print_json(
> @@ -57,6 +67,7 @@ static int fwts_log_print_json(
> time_t now;
> json_object *header;
> json_object *json_log = (json_object*)json_stack[json_stack_index-1].log;
> + json_object *obj;
> char *str;
>
> if (!((field & LOG_FIELD_MASK) & fwts_log_filter))
> @@ -68,31 +79,53 @@ static int fwts_log_print_json(
> time(&now);
> localtime_r(&now, &tm);
>
> - header = json_object_new_object();
> - json_object_object_add(header, "line_num", json_object_new_int(log_file->line_number));
> + if ((header = json_object_new_object()) == NULL)
> + fwts_log_out_of_memory_json();
> +
> + if ((obj = json_object_new_int(log_file->line_number)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "line_num", obj);
> +
> snprintf(tmpbuf, sizeof(tmpbuf), "%2.2d/%2.2d/%-2.2d",
> tm.tm_mday, tm.tm_mon + 1, (tm.tm_year+1900) % 100);
> - json_object_object_add(header, "date", json_object_new_string(tmpbuf));
> + if ((obj = json_object_new_string(tmpbuf)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "date", obj);
> +
> snprintf(tmpbuf, sizeof(tmpbuf), "%2.2d:%2.2d:%2.2d",
> tm.tm_hour, tm.tm_min, tm.tm_sec);
> - json_object_object_add(header, "time", json_object_new_string(tmpbuf));
> - json_object_object_add(header, "field_type",
> - json_object_new_string(fwts_log_field_to_str_full(field)));
> + if ((obj = json_object_new_string(tmpbuf)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "time", obj);
> +
> + if ((obj = json_object_new_string(fwts_log_field_to_str_full(field))) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "field_type", obj);
>
> str = fwts_log_level_to_str(level);
> if (!strcmp(str, " "))
> str = "None";
> - json_object_object_add(header, "level",
> - json_object_new_string(str));
> + if ((obj = json_object_new_string(str)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "level", obj);
> +
> + if ((obj = json_object_new_string(*status ? status : "None")) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "status", obj);
>
> - json_object_object_add(header, "status", json_object_new_string(*status ? status : "None"));
> - json_object_object_add(header, "failure_label", json_object_new_string(label && *label ? label : "None"));
> + if ((obj = json_object_new_string(label && *label ? label : "None")) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "failure_label", obj);
>
> /* Redundant really
> - json_object_object_add(header, "owner",
> - json_object_new_string(log->owner));
> + if ((obj = json_object_new_string(log->owner)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "owner", obj);
> */
> - json_object_object_add(header, "log_text", json_object_new_string(buffer));
> +
> + if ((obj = json_object_new_string(buffer)) == NULL)
> + fwts_log_out_of_memory_json();
> + json_object_object_add(header, "log_text", obj);
>
> json_object_array_add(json_log, header);
> log_file->line_number++; /* This is academic really */
> @@ -123,15 +156,25 @@ static void fwts_log_section_begin_json(fwts_log_file *log_file, const char *nam
> json_object *json_obj;
> json_object *json_log;
>
> - json_obj = json_object_new_object();
> - json_log = json_object_new_array();
> + if ((json_obj = json_object_new_object()) == NULL)
> + fwts_log_out_of_memory_json();
> +
> + if ((json_log = json_object_new_array()) == NULL)
> + fwts_log_out_of_memory_json();
> +
> + /*
> + * unfortunately json_object_object_add can fail on
> + * a strdup, but it doesn't check this and doesn't
> + * tell us about this either. Bit lame really.
> + */
> json_object_object_add(json_obj, name, json_log);
>
> json_stack[json_stack_index].obj = json_obj;
> json_stack[json_stack_index].log = json_log;
>
> if (json_stack_index > 0)
> - json_object_array_add(json_stack[json_stack_index-1].log, json_obj);
> + if (json_object_array_add(json_stack[json_stack_index-1].log, json_obj) != 0)
> + fwts_log_out_of_memory_json();
>
> if (json_stack_index < MAX_JSON_STACK)
> json_stack_index++;
> --
> 1.7.10.4
>
Acked-by: Keng-Yu Lin <kengyu at canonical.com>
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