From 33e2c5b2f63844a3e08fc287d0d8921cbc3b8f86 Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Tue, 30 Nov 2021 10:55:43 +0000 Subject: output: MYSQL: improve mapping of DB columns to input-keys Currently, we copy the column-name to a buffer, iterate over it to replace the underscores with full-stops, using `strchr` from the start of the buffer on each iteration, then copy the buffer to the input-key's `name` member. Apart from the inefficiency, `strncpy` is used to do the copies, which leads gcc to complain: ulogd_output_MYSQL.c:149:17: warning: `strncpy` output may be truncated copying 31 bytes from a string of length 31 Furthermore, the buffer is not initialized, which means that there is also a possible buffer overrun if the column-name is too long, since `strncpy` will not append a NUL. Instead, copy the column-name directly to the input-key using `snprintf`, and run `strchr` from the last underscore on each iteration. Signed-off-by: Jeremy Sowden Signed-off-by: Pablo Neira Ayuso --- output/mysql/ulogd_output_MYSQL.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/output/mysql/ulogd_output_MYSQL.c b/output/mysql/ulogd_output_MYSQL.c index 66151fe..9727e30 100644 --- a/output/mysql/ulogd_output_MYSQL.c +++ b/output/mysql/ulogd_output_MYSQL.c @@ -135,18 +135,18 @@ static int get_columns_mysql(struct ulogd_pluginstance *upi) } for (i = 0; (field = mysql_fetch_field(result)); i++) { - char buf[ULOGD_MAX_KEYLEN+1]; char *underscore; + snprintf(upi->input.keys[i].name, + sizeof(upi->input.keys[i].name), + "%s", field->name); + /* replace all underscores with dots */ - strncpy(buf, field->name, ULOGD_MAX_KEYLEN); - while ((underscore = strchr(buf, '_'))) + for (underscore = upi->input.keys[i].name; + (underscore = strchr(underscore, '_')); ) *underscore = '.'; - DEBUGP("field '%s' found\n", buf); - - /* add it to list of input keys */ - strncpy(upi->input.keys[i].name, buf, ULOGD_MAX_KEYLEN); + DEBUGP("field '%s' found\n", upi->input.keys[i].name); } /* MySQL Auto increment ... ID :) */ upi->input.keys[0].flags |= ULOGD_KEYF_INACTIVE; -- cgit v1.2.3