map: add support for adding dns regex patterns

This will be used for hostname based dscp mark rules

Signed-off-by: Felix Fietkau <nbd@nbd.name>

2 files changed, 54 insertions, 8 deletions

diff --git a/map.c b/map.c
index 2eacfcd..7f8c20d 100644
--- a/map.c
+++ b/map.c
@@ -38,6 +38,7 @@ static const struct {
 	[CL_MAP_IPV4_ADDR] = { "ipv4_map", "ipv4_addr" },
 	[CL_MAP_IPV6_ADDR] = { "ipv6_map", "ipv6_addr" },
 	[CL_MAP_CONFIG] = { "config", "config" },
+	[CL_MAP_DNS] = { "dns", "dns" },
 };
 
 static const struct {
@@ -169,7 +170,7 @@ int qosify_map_init(void)
 {
 	int i;
 
-	for (i = 0; i < ARRAY_SIZE(qosify_map_fds); i++) {
+	for (i = 0; i < CL_MAP_DNS; i++) {
 		qosify_map_fds[i] = qosify_map_get_fd(i);
 		if (qosify_map_fds[i] < 0)
 			return -1;
@@ -210,9 +211,37 @@ static int qosify_map_entry_cmp(const void *k1, const void *k2, void *ptr)
 	if (d1->id != d2->id)
 		return d2->id - d1->id;
 
+	if (d1->id == CL_MAP_DNS)
+		return strcmp(d1->addr.dns.pattern, d2->addr.dns.pattern);
+
 	return memcmp(&d1->addr, &d2->addr, sizeof(d1->addr));
 }
 
+static struct qosify_map_entry *
+__qosify_map_alloc_entry(struct qosify_map_data *data)
+{
+	struct qosify_map_entry *e;
+	char *pattern;
+
+	if (data->id < CL_MAP_DNS) {
+		e = calloc(1, sizeof(*e));
+		memcpy(&e->data.addr, &data->addr, sizeof(e->data.addr));
+
+		return e;
+	}
+
+	e = calloc_a(sizeof(*e), &pattern, strlen(data->addr.dns.pattern) + 1);
+	strcpy(pattern, data->addr.dns.pattern);
+	e->data.addr.dns.pattern = pattern;
+	if (regcomp(&e->data.addr.dns.regex, pattern,
+		    REG_EXTENDED | REG_ICASE | REG_NOSUB)) {
+		free(e);
+		return NULL;
+	}
+
+	return e;
+}
+
 static void __qosify_map_set_entry(struct qosify_map_data *data)
 {
 	int fd = qosify_map_fds[data->id];
@@ -227,10 +256,12 @@ static void __qosify_map_set_entry(struct qosify_map_data *data)
 		if (!add)
 			return;
 
-		e = calloc(1, sizeof(*e));
+		e = __qosify_map_alloc_entry(data);
+		if (!e)
+			return;
+
 		e->avl.key = &e->data;
 		e->data.id = data->id;
-		memcpy(&e->data.addr, &data->addr, sizeof(e->data.addr));
 		avl_insert(&map_data, &e->avl);
 	} else {
 		prev_dscp = e->data.dscp;
@@ -250,7 +281,7 @@ static void __qosify_map_set_entry(struct qosify_map_data *data)
 		e->data.dscp = e->data.file_dscp;
 	}
 
-	if (e->data.dscp != prev_dscp)
+	if (e->data.dscp != prev_dscp && data->id < CL_MAP_DNS)
 		bpf_map_update_elem(fd, &data->addr, &e->data.dscp, BPF_ANY);
 
 	if (add) {
@@ -320,6 +351,9 @@ int qosify_map_set_entry(enum qosify_map_id id, bool file, const char *str, uint
 	};
 
 	switch (id) {
+	case CL_MAP_DNS:
+		data.addr.dns.pattern = str;
+		break;
 	case CL_MAP_TCP_PORTS:
 	case CL_MAP_UDP_PORTS:
 		return qosify_map_set_port(&data, str);
@@ -401,6 +435,8 @@ qosify_map_parse_line(char *str)
 	if (dscp < 0)
 		return;
 
+	if (!strncmp(key, "dns:", 4))
+		qosify_map_set_entry(CL_MAP_DNS, true, key + 4, dscp);
 	if (!strncmp(key, "tcp:", 4))
 		qosify_map_set_entry(CL_MAP_TCP_PORTS, true, key + 4, dscp);
 	else if (!strncmp(key, "udp:", 4))
@@ -511,7 +547,8 @@ static void qosify_map_free_entry(struct qosify_map_entry *e)
 	int fd = qosify_map_fds[e->data.id];
 
 	avl_delete(&map_data, &e->avl);
-	bpf_map_delete_elem(fd, &e->data.addr);
+	if (e->data.id < CL_MAP_DNS)
+		bpf_map_delete_elem(fd, &e->data.addr);
 	free(e);
 }
 
@@ -583,22 +620,25 @@ void qosify_map_dump(struct blob_buf *b)
 
 		blobmsg_add_string(b, "type", qosify_map_info[e->data.id].type_name);
 
-		buf = blobmsg_alloc_string_buffer(b, "value", buf_len);
 		switch (e->data.id) {
 		case CL_MAP_TCP_PORTS:
 		case CL_MAP_UDP_PORTS:
-			snprintf(buf, buf_len, "%d", ntohs(e->data.addr.port));
+			blobmsg_printf(b, "addr", "%d", ntohs(e->data.addr.port));
 			break;
 		case CL_MAP_IPV4_ADDR:
 		case CL_MAP_IPV6_ADDR:
+			buf = blobmsg_alloc_string_buffer(b, "addr", buf_len);
 			af = e->data.id == CL_MAP_IPV6_ADDR ? AF_INET6 : AF_INET;
 			inet_ntop(af, &e->data.addr, buf, buf_len);
+			blobmsg_add_string_buffer(b);
+			break;
+		case CL_MAP_DNS:
+			blobmsg_add_string(b, "addr", e->data.addr.dns.pattern);
 			break;
 		default:
 			*buf = 0;
 			break;
 		}
-		blobmsg_add_string_buffer(b);
 		blobmsg_close_table(b, c);
 	}
 	blobmsg_close_array(b, a);
diff --git a/qosify.h b/qosify.h
index e6934ad..285543a 100644
--- a/qosify.h
+++ b/qosify.h
@@ -6,6 +6,7 @@
 #define __QOS_CLASSIFY_H
 
 #include <stdbool.h>
+#include <regex.h>
 
 #include <bpf/bpf.h>
 #include <bpf/libbpf.h>
@@ -29,6 +30,7 @@ enum qosify_map_id {
 	CL_MAP_IPV4_ADDR,
 	CL_MAP_IPV6_ADDR,
 	CL_MAP_CONFIG,
+	CL_MAP_DNS,
 	__CL_MAP_MAX,
 };
 
@@ -45,6 +47,10 @@ struct qosify_map_data {
 		uint32_t port;
 		struct in_addr ip;
 		struct in6_addr ip6;
+		struct {
+			const char *pattern;
+			regex_t regex;
+		} dns;
 	} addr;
 };