From 0a9fa5603a435afed955f5458a17331b7f2f18ca Mon Sep 17 00:00:00 2001 From: Jeremy Sowden Date: Tue, 30 Nov 2021 10:55:40 +0000 Subject: output: DBI: 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, iterate over it a second time to lower-case all letters, and finally copy the buffer to the input-key's `name` member. In addition to being inefficient, `strncpy` is used to do the copies, which leads gcc to complain: ulogd_output_DBI.c:160:17: 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 then iterate over it once to replace underscores and lower-case letters. Signed-off-by: Jeremy Sowden Signed-off-by: Pablo Neira Ayuso --- output/dbi/ulogd_output_DBI.c | 34 +++++++++++++--------------------- 1 file changed, 13 insertions(+), 21 deletions(-) (limited to 'output') diff --git a/output/dbi/ulogd_output_DBI.c b/output/dbi/ulogd_output_DBI.c index b4a5bac..fff9abc 100644 --- a/output/dbi/ulogd_output_DBI.c +++ b/output/dbi/ulogd_output_DBI.c @@ -91,15 +91,6 @@ static struct config_keyset dbi_kset = { #define dbtype_ce(x) (x->ces[DB_CE_NUM+6]) -/* lower-cases s in place */ -static void str_tolower(char *s) -{ - while(*s) { - *s = tolower(*s); - s++; - } -} - /* find out which columns the table has */ static int get_columns_dbi(struct ulogd_pluginstance *upi) { @@ -140,24 +131,25 @@ static int get_columns_dbi(struct ulogd_pluginstance *upi) } for (ui=1; ui<=upi->input.num_keys; ui++) { - char buf[ULOGD_MAX_KEYLEN+1]; - char *underscore; - const char* field_name = dbi_result_get_field_name(pi->result, ui); + const char *field_name = dbi_result_get_field_name(pi->result, ui); + char *cp; if (!field_name) break; - /* replace all underscores with dots */ - strncpy(buf, field_name, ULOGD_MAX_KEYLEN); - while ((underscore = strchr(buf, '_'))) - *underscore = '.'; - - str_tolower(buf); + snprintf(upi->input.keys[ui - 1].name, + sizeof(upi->input.keys[ui - 1].name), + "%s", field_name); - DEBUGP("field '%s' found: ", buf); + /* down-case and replace all underscores with dots */ + for (cp = upi->input.keys[ui - 1].name; *cp; cp++) { + if (*cp == '_') + *cp = '.'; + else + *cp = tolower(*cp); + } - /* add it to list of input keys */ - strncpy(upi->input.keys[ui-1].name, buf, ULOGD_MAX_KEYLEN); + DEBUGP("field '%s' found: ", upi->input.keys[ui - 1].name); } /* ID is a sequence */ -- cgit v1.2.3