Merge branch 'master' of https://github.com/sogou/workflow into nossl

src/protocol/DnsMessage.h

@@ -152,6 +152,109 @@ public:
 		parser->question.qname = strdup(name.c_str());
 	}
 
+	int add_a_record(int section, const char *name,
+					 uint16_t rclass, uint32_t ttl,
+					 const void *data)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_raw_record(name, DNS_TYPE_A, rclass, ttl, 4, data, list);
+	}
+
+	int add_aaaa_record(int section, const char *name,
+						uint16_t rclass, uint32_t ttl,
+						const void *data)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_raw_record(name, DNS_TYPE_AAAA, rclass, ttl,
+								  16, data, list);
+	}
+
+	int add_ns_record(int section, const char *name,
+					  uint16_t rclass, uint32_t ttl,
+					  const char *data)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_str_record(name, DNS_TYPE_NS, rclass, ttl, data, list);
+	}
+
+	int add_cname_record(int section, const char *name,
+						 uint16_t rclass, uint32_t ttl,
+						 const char *data)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_str_record(name, DNS_TYPE_CNAME, rclass, ttl,
+								  data, list);
+	}
+
+	int add_ptr_record(int section, const char *name,
+					   uint16_t rclass, uint32_t ttl,
+					   const char *data)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_str_record(name, DNS_TYPE_PTR, rclass, ttl, data, list);
+	}
+
+	int add_soa_record(int section, const char *name,
+					   uint16_t rclass, uint32_t ttl,
+					   const char *mname, const char *rname,
+					   uint32_t serial, int32_t refresh,
+					   int32_t retry, int32_t expire, uint32_t minimum)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_soa_record(name, rclass, ttl, mname, rname, serial,
+								  refresh, retry, expire, minimum, list);
+	}
+
+	int add_srv_record(int section, const char *name,
+					   uint16_t rclass, uint32_t ttl,
+					   uint16_t priority, uint16_t weight, uint16_t port,
+					   const char *target)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_srv_record(name, rclass, ttl,
+								  priority, weight, port, target, list);
+	}
+
+	int add_mx_record(int section, const char *name,
+					  uint16_t rclass, uint32_t ttl,
+					  int16_t preference, const char *exchange)
+	{
+		struct list_head *list = get_section(section);
+
+		if (!list)
+			return -1;
+
+		return dns_add_mx_record(name, rclass, ttl, preference, exchange, list);
+	}
+
 	// Inner use only
 	bool is_single_packet() const
 	{
@@ -191,6 +294,22 @@ private:
 	int encode_reply();
 	int encode_truncation_reply();
 
+	struct list_head *get_section(int section)
+	{
+		switch (section)
+		{
+		case DNS_ANSWER_SECTION:
+			return &(parser->answer_list);
+		case DNS_AUTHORITY_SECTION:
+			return &(parser->authority_list);
+		case DNS_ADDITIONAL_SECTION:
+			return &(parser->additional_list);
+		default:
+			errno = EINVAL;
+			return NULL;
+		}
+	}
+
 	// size of msgbuf, but in network byte order
 	uint16_t msgsize;
 };

src/protocol/dns_parser.c

@@ -100,11 +100,16 @@ static int __dns_parser_parse_host(char *phost, dns_parser_t *parser)
 		else if ((len & 0xC0) == 0xC0)
 		{
 			pointer = __dns_parser_uint16(*cur) & 0x3FFF;
-			*cur += 2;
 
 			if (pointer >= parser->msgsize)
 				return -2;
 
+			// pointer must point to a prior position
+			if ((const char *)parser->msgbase + pointer >= *cur)
+				return -2;
+
+			*cur += 2;
+
 			// backup cur only when the first pointer occurs
 			if (curbackup == NULL)
 				curbackup = *cur;
@@ -909,6 +914,186 @@ int dns_record_cursor_find_cname(const char *name,
 	return 1;
 }
 
+int dns_add_raw_record(const char *name, uint16_t type, uint16_t rclass,
+					   uint32_t ttl, uint16_t rlen, const void *rdata,
+					   struct list_head *list)
+{
+	struct __dns_record_entry *entry;
+	size_t entry_size = sizeof (struct __dns_record_entry) + rlen;
+
+	entry = (struct __dns_record_entry *)malloc(entry_size);
+	if (!entry)
+		return -1;
+
+	entry->record.name = strdup(name);
+	if (!entry->record.name)
+	{
+		free(entry);
+		return -1;
+	}
+
+	entry->record.type = type;
+	entry->record.rclass = rclass;
+	entry->record.ttl = ttl;
+	entry->record.rdlength = rlen;
+	entry->record.rdata = (void *)(entry + 1);
+	memcpy(entry->record.rdata, rdata, rlen);
+	list_add_tail(&entry->entry_list, list);
+
+	return 0;
+}
+
+int dns_add_str_record(const char *name, uint16_t type, uint16_t rclass,
+					   uint32_t ttl, const char *rdata,
+					   struct list_head *list)
+{
+	size_t rlen = strlen(rdata);
+	// record.rdlength has no meaning for parsed record types, ignore its
+	// correctness, same for soa/srv/mx record
+	return dns_add_raw_record(name, type, rclass, ttl, rlen+1, rdata, list);
+}
+
+int dns_add_soa_record(const char *name, uint16_t rclass, uint32_t ttl,
+					   const char *mname, const char *rname,
+					   uint32_t serial, int32_t refresh,
+					   int32_t retry, int32_t expire, uint32_t minimum,
+					   struct list_head *list)
+{
+	struct __dns_record_entry *entry;
+	struct dns_record_soa *soa;
+	size_t entry_size;
+	char *pname, *pmname, *prname;
+
+	entry_size = sizeof (struct __dns_record_entry) +
+				 sizeof (struct dns_record_soa);
+
+	entry = (struct __dns_record_entry *)malloc(entry_size);
+	if (!entry)
+		return -1;
+
+	entry->record.rdata = (void *)(entry + 1);
+	entry->record.rdlength = 0;
+	soa = (struct dns_record_soa *)(entry->record.rdata);
+
+	pname = strdup(name);
+	pmname = strdup(mname);
+	prname = strdup(rname);
+
+	if (!pname || !pmname || !prname)
+	{
+		free(pname);
+		free(pmname);
+		free(prname);
+		free(entry);
+		return -1;
+	}
+
+	soa->mname = pmname;
+	soa->rname = prname;
+	soa->serial = serial;
+	soa->refresh = refresh;
+	soa->retry = retry;
+	soa->expire = expire;
+	soa->minimum = minimum;
+
+	entry->record.name = pname;
+	entry->record.type = DNS_TYPE_SOA;
+	entry->record.rclass = rclass;
+	entry->record.ttl = ttl;
+	list_add_tail(&entry->entry_list, list);
+
+	return 0;
+}
+
+int dns_add_srv_record(const char *name, uint16_t rclass, uint32_t ttl,
+					   uint16_t priority, uint16_t weight,
+					   uint16_t port, const char *target,
+					   struct list_head *list)
+{
+	struct __dns_record_entry *entry;
+	struct dns_record_srv *srv;
+	size_t entry_size;
+	char *pname, *ptarget;
+
+	entry_size = sizeof (struct __dns_record_entry) +
+				 sizeof (struct dns_record_srv);
+
+	entry = (struct __dns_record_entry *)malloc(entry_size);
+	if (!entry)
+		return -1;
+
+	entry->record.rdata = (void *)(entry + 1);
+	entry->record.rdlength = 0;
+	srv = (struct dns_record_srv *)(entry->record.rdata);
+
+	pname = strdup(name);
+	ptarget = strdup(target);
+
+	if (!pname || !ptarget)
+	{
+		free(pname);
+		free(ptarget);
+		free(entry);
+		return -1;
+	}
+
+	srv->priority = priority;
+	srv->weight = weight;
+	srv->port = port;
+	srv->target = ptarget;
+
+	entry->record.name = pname;
+	entry->record.type = DNS_TYPE_SRV;
+	entry->record.rclass = rclass;
+	entry->record.ttl = ttl;
+	list_add_tail(&entry->entry_list, list);
+
+	return 0;
+}
+
+int dns_add_mx_record(const char *name, uint16_t rclass, uint32_t ttl,
+					  int16_t preference, const char *exchange,
+					  struct list_head *list)
+{
+	struct __dns_record_entry *entry;
+	struct dns_record_mx *mx;
+	size_t entry_size;
+	char *pname, *pexchange;
+
+	entry_size = sizeof (struct __dns_record_entry) +
+				 sizeof (struct dns_record_mx);
+
+	entry = (struct __dns_record_entry *)malloc(entry_size);
+	if (!entry)
+		return -1;
+
+	entry->record.rdata = (void *)(entry + 1);
+	entry->record.rdlength = 0;
+	mx = (struct dns_record_mx *)(entry->record.rdata);
+
+	pname = strdup(name);
+	pexchange = strdup(exchange);
+
+	if (!pname || !pexchange)
+	{
+		free(pname);
+		free(pexchange);
+		free(entry);
+		return -1;
+	}
+
+	mx->preference = preference;
+	mx->exchange = pexchange;
+
+	entry->record.name = pname;
+	entry->record.type = DNS_TYPE_MX;
+	entry->record.rclass = rclass;
+	entry->record.ttl = ttl;
+	list_add_tail(&entry->entry_list, list);
+
+	return 0;
+}
+
 const char *dns_type2str(int type)
 {
 	switch (type)

src/protocol/dns_parser.h

@@ -78,6 +78,13 @@ enum
 	DNS_RCODE_REFUSED
 };
 
+enum
+{
+	DNS_ANSWER_SECTION = 1,
+	DNS_AUTHORITY_SECTION = 2,
+	DNS_ADDITIONAL_SECTION = 3,
+};
+
 /**
  * dns_header_t is a struct to describe the header of a dns
  * request or response packet, but the byte order is not
@@ -207,6 +214,29 @@ int dns_record_cursor_find_cname(const char *name,
 								 const char **cname,
 								 dns_record_cursor_t *cursor);
 
+int dns_add_raw_record(const char *name, uint16_t type, uint16_t rclass,
+					   uint32_t ttl, uint16_t rlen, const void *rdata,
+					   struct list_head *list);
+
+int dns_add_str_record(const char *name, uint16_t type, uint16_t rclass,
+					   uint32_t ttl, const char *rdata,
+					   struct list_head *list);
+
+int dns_add_soa_record(const char *name, uint16_t rclass, uint32_t ttl,
+					   const char *mname, const char *rname,
+					   uint32_t serial, int32_t refresh,
+					   int32_t retry, int32_t expire, uint32_t minimum,
+					   struct list_head *list);
+
+int dns_add_srv_record(const char *name, uint16_t rclass, uint32_t ttl,
+					   uint16_t priority, uint16_t weight,
+					   uint16_t port, const char *target,
+					   struct list_head *list);
+
+int dns_add_mx_record(const char *name, uint16_t rclass, uint32_t ttl,
+					  int16_t preference, const char *exchange,
+					  struct list_head *list);
+
 const char *dns_type2str(int type);
 const char *dns_class2str(int dnsclass);
 const char *dns_opcode2str(int opcode);