--- l2_ch_filter.c 2001/09/12 09:42:34 1.8
+++ l2_ch_filter.c 2001/09/25 09:35:17 1.9
@@ -28,40 +28,119 @@
*/
#include "l2.h"
+#include "l2_ut_pcre.h"
+/* declare private channel configuration */
+typedef struct {
+ char *szRegex;
+ int bNegate;
+ pcre *pcreRegex;
+ pcre_extra *pcreExtra;
+} l2_ch_filter_t;
+
+/* create channel */
static l2_result_t hook_create(l2_context_t *ctx, l2_channel_t *ch)
{
+ l2_ch_filter_t *cfg;
+
+ /* allocate private channel configuration */
+ if ((cfg = (l2_ch_filter_t *)malloc(sizeof(l2_ch_filter_t))) == NULL)
+ return L2_ERR_MEM;
+
+ /* initialize configuration with reasonable defaults */
+ cfg->szRegex = NULL;
+ cfg->bNegate = 0;
+ cfg->pcreRegex = NULL;
+ cfg->pcreExtra = NULL;
+
+ /* link private channel configuration into channel context */
+ ctx->vp = cfg;
+
return L2_OK;
}
+/* configure channel */
static l2_result_t hook_configure(l2_context_t *ctx, l2_channel_t *ch, const char *fmt, va_list ap)
{
- return L2_OK;
-}
+ l2_ch_filter_t *cfg = (l2_ch_filter_t *)ctx->vp;
+ l2_param_t pa[3];
+ l2_result_t rv;
+ const char *szError;
+ int nErrorOffset;
+
+ /* feed and call generic parameter parsing engine */
+ L2_PARAM_SET(pa[0], regex, STRING, &cfg->szRegex);
+ L2_PARAM_SET(pa[1], negate, INT, &cfg->bNegate);
+ L2_PARAM_END(pa[2]);
+ if ((rv = l2_util_setparams(pa, fmt, ap)) != L2_OK)
+ return rv;
+
+ /* translate regular expression into finite state machine */
+ if (cfg->szRegex != NULL) {
+ /* compile regular expression into FSM */
+ if ((cfg->pcreRegex = pcre_compile(cfg->szRegex, 0, &szError, &nErrorOffset, NULL)) == NULL) {
+ l2_channel_errorinfo(ch, L2_ERR_ARG, "%s ('%c')", szError, cfg->szRegex[nErrorOffset]);
+ return L2_ERR_ARG;
+ }
+ /* study FSM for more performance */
+ if ((cfg->pcreExtra = pcre_study(cfg->pcreRegex, 0, &szError)) == NULL) {
+ free(cfg->pcreRegex);
+ cfg->pcreRegex = NULL;
+ l2_channel_errorinfo(ch, L2_ERR_ARG, "%s", szError);
+ return L2_ERR_ARG;
+ }
+ }
-static l2_result_t hook_open(l2_context_t *ctx, l2_channel_t *ch)
-{
return L2_OK;
}
+/* write to channel */
static l2_result_t hook_write(l2_context_t *ctx, l2_channel_t *ch,
l2_level_t level, const char *buf, size_t buf_size)
{
- return L2_OK;
-}
-
-static l2_result_t hook_flush(l2_context_t *ctx, l2_channel_t *ch)
-{
- return L2_OK;
-}
+ l2_ch_filter_t *cfg = (l2_ch_filter_t *)ctx->vp;
+ l2_channel_t *downstream = l2_channel_downstream(ch);
+ l2_result_t rv;
+ int bPass;
+
+ bPass = TRUE;
+
+ /* apply filter */
+ if (cfg->pcreRegex != NULL && cfg->pcreExtra != NULL) {
+ if (pcre_exec(cfg->pcreRegex, cfg->pcreExtra, buf, buf_size, 0, 0, NULL, 0) > 0)
+ bPass = TRUE;
+ else
+ bPass = FALSE;
+ if (cfg->bNegate)
+ bPass = !bPass;
+ }
+
+ /* write to downstream channel */
+ if (bPass)
+ if ((rv = l2_channel_write(downstream, level, buf, buf_size)) != L2_OK)
+ return rv;
-static l2_result_t hook_close(l2_context_t *ctx, l2_channel_t *ch)
-{
return L2_OK;
}
static l2_result_t hook_destroy(l2_context_t *ctx, l2_channel_t *ch)
{
+ l2_ch_filter_t *cfg = (l2_ch_filter_t *)ctx->vp;
+ l2_channel_t *downstream = l2_channel_downstream(ch);
+ l2_result_t rv;
+
+ /* destroy downstream channel */
+ if ((rv = l2_channel_destroy(downstream)) != L2_OK)
+ return rv;
+
+ /* destroy channel configuration */
+ if (cfg->szRegex != NULL)
+ free(cfg->szRegex);
+ if (cfg->pcreRegex != NULL)
+ free(cfg->pcreRegex);
+ if (cfg->pcreExtra != NULL)
+ free(cfg->pcreExtra);
+
return L2_OK;
}
@@ -69,10 +148,10 @@
L2_CHANNEL_FILTER,
hook_create,
hook_configure,
- hook_open,
+ NULL,
hook_write,
- hook_flush,
- hook_close,
+ NULL,
+ NULL,
hook_destroy
};
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