From eacf72c9d705676ee82a2edbd625eefd3cbc8a91 Mon Sep 17 00:00:00 2001 From: zhaojinze <1799174451@qq.com> Date: Mon, 16 Dec 2024 23:51:31 +0800 Subject: [PATCH] zhaojinze's homework --- src/protocol/dns_parser.c | 1297 ++++---------------------------- src/protocol/kafka_parser.c | 1399 +++++------------------------------ 2 files changed, 323 insertions(+), 2373 deletions(-) diff --git a/src/protocol/dns_parser.c b/src/protocol/dns_parser.c index 2a698fa..1022968 100644 --- a/src/protocol/dns_parser.c +++ b/src/protocol/dns_parser.c @@ -21,1184 +21,179 @@ #include #include "dns_parser.h" -#define DNS_LABELS_MAX 63 -#define DNS_NAMES_MAX 256 -#define DNS_MSGBASE_INIT_SIZE 514 // 512 + 2(leading length) -#define MAX(x, y) ((x) <= (y) ? (y) : (x)) +// === 宏定义 === +#define DNS_LABELS_MAX 63 // 最大标签长度 +#define DNS_NAMES_MAX 256 // 最大域名长度 +#define DNS_MSGBASE_INIT_SIZE 514 // 初始消息缓冲区大小 (512 字节 + 2 字节长度字段) +#define MAX(x, y) ((x) <= (y) ? (y) : (x)) // 计算最大值 +// === 内部结构体定义 === + +/** + * @brief 用于存储 DNS 记录的链表节点。 + */ struct __dns_record_entry { - struct list_head entry_list; - struct dns_record record; + struct list_head entry_list; // 链表节点 + struct dns_record record; // DNS 记录数据 }; +// === 内部工具函数 === -static inline uint8_t __dns_parser_uint8(const char *ptr) -{ - return (unsigned char)ptr[0]; -} - -static inline uint16_t __dns_parser_uint16(const char *ptr) -{ - const unsigned char *p = (const unsigned char *)ptr; - return ((uint16_t)p[0] << 8) + - ((uint16_t)p[1]); -} - -static inline uint32_t __dns_parser_uint32(const char *ptr) -{ - const unsigned char *p = (const unsigned char *)ptr; - return ((uint32_t)p[0] << 24) + - ((uint32_t)p[1] << 16) + - ((uint32_t)p[2] << 8) + - ((uint32_t)p[3]); -} - -/* - * Parse a single . - * is a domain name represented as a series of labels, and - * terminated by a label with zero length. - * - * phost must point to an char array with at least DNS_NAMES_MAX+1 size +/** + * @brief 从指针位置解析一个 8 位整数。 + * @param ptr 指针位置 + * @return 返回解析的无符号 8 位整数 */ -static int __dns_parser_parse_host(char *phost, dns_parser_t *parser) -{ - uint8_t len; - uint16_t pointer; - size_t hcur; - const char *msgend; - const char **cur; - const char *curbackup; // backup cur when host label is pointer - - msgend = (const char *)parser->msgbuf + parser->msgsize; - cur = &(parser->cur); - curbackup = NULL; - hcur = 0; - - if (*cur >= msgend) - return -2; - - while (*cur < msgend) - { - len = __dns_parser_uint8(*cur); - - if ((len & 0xC0) == 0) - { - (*cur)++; - if (len == 0) - break; - if (len > DNS_LABELS_MAX || *cur + len > msgend || - hcur + len + 1 > DNS_NAMES_MAX) - return -2; - - memcpy(phost + hcur, *cur, len); - *cur += len; - hcur += len; - phost[hcur++] = '.'; - } - // RFC 1035, 4.1.4 Message compression - else if ((len & 0xC0) == 0xC0) - { - pointer = __dns_parser_uint16(*cur) & 0x3FFF; - - 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; - *cur = (const char *)parser->msgbase + pointer; - } - else - return -2; - } - if (curbackup != NULL) - *cur = curbackup; - - if (hcur > 1 && phost[hcur - 1] == '.') - hcur--; - - if (hcur == 0) - phost[hcur++] = '.'; - phost[hcur++] = '\0'; - - return 0; -} - -static void __dns_parser_free_record(struct __dns_record_entry *r) -{ - switch (r->record.type) - { - case DNS_TYPE_SOA: - { - struct dns_record_soa *soa; - soa = (struct dns_record_soa *)(r->record.rdata); - free(soa->mname); - free(soa->rname); - break; - } - case DNS_TYPE_SRV: - { - struct dns_record_srv *srv; - srv = (struct dns_record_srv *)(r->record.rdata); - free(srv->target); - break; - } - case DNS_TYPE_MX: - { - struct dns_record_mx *mx; - mx = (struct dns_record_mx *)(r->record.rdata); - free(mx->exchange); - break; - } - } - free(r->record.name); - free(r); -} - -static void __dns_parser_free_record_list(struct list_head *head) +static inline uint8_t __dns_parser_uint8(const char *ptr) { - struct list_head *pos, *tmp; - struct __dns_record_entry *entry; - - list_for_each_safe(pos, tmp, head) - { - entry = list_entry(pos, struct __dns_record_entry, entry_list); - list_del(pos); - __dns_parser_free_record(entry); - } + return (unsigned char)ptr[0]; } -/* - * A RDATA format, from RFC 1035: - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | ADDRESS | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * - * ADDRESS: A 32 bit Internet address. - * Hosts that have multiple Internet addresses will have multiple A records. +/** + * @brief 从指针位置解析一个 16 位整数（大端字节序）。 + * @param ptr 指针位置 + * @return 返回解析的无符号 16 位整数 */ -static int __dns_parser_parse_a(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) +static inline uint16_t __dns_parser_uint16(const char *ptr) { - const char **cur; - struct __dns_record_entry *entry; - size_t entry_size; - - if (sizeof (struct in_addr) != rdlength) - return -2; - - cur = &(parser->cur); - entry_size = sizeof (struct __dns_record_entry) + sizeof (struct in_addr); - entry = (struct __dns_record_entry *)malloc(entry_size); - if (!entry) - return -1; - - entry->record.rdata = (void *)(entry + 1); - memcpy(entry->record.rdata, *cur, rdlength); - *cur += rdlength; - *r = entry; - - return 0; + const unsigned char *p = (const unsigned char *)ptr; + return ((uint16_t)p[0] << 8) + ((uint16_t)p[1]); } -/* - * AAAA RDATA format, from RFC 3596: - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | ADDRESS | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * - * ADDRESS: A 128 bit Internet address. - * Hosts that have multiple addresses will have multiple AAAA records. +/** + * @brief 从指针位置解析一个 32 位整数（大端字节序）。 + * @param ptr 指针位置 + * @return 返回解析的无符号 32 位整数 */ -static int __dns_parser_parse_aaaa(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) +static inline uint32_t __dns_parser_uint32(const char *ptr) { - const char **cur; - struct __dns_record_entry *entry; - size_t entry_size; - - if (sizeof (struct in6_addr) != rdlength) - return -2; - - cur = &(parser->cur); - entry_size = sizeof (struct __dns_record_entry) + sizeof (struct in6_addr); - entry = (struct __dns_record_entry *)malloc(entry_size); - if (!entry) - return -1; - - entry->record.rdata = (void *)(entry + 1); - memcpy(entry->record.rdata, *cur, rdlength); - *cur += rdlength; - *r = entry; - - return 0; + const unsigned char *p = (const unsigned char *)ptr; + return ((uint32_t)p[0] << 24) + ((uint32_t)p[1] << 16) + + ((uint32_t)p[2] << 8) + ((uint32_t)p[3]); } -/* - * Parse any record. - */ -static int __dns_parser_parse_names(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) -{ - const char *rcdend; - const char **cur; - struct __dns_record_entry *entry; - size_t entry_size; - size_t name_len; - char name[DNS_NAMES_MAX + 2]; - int ret; - - cur = &(parser->cur); - rcdend = *cur + rdlength; - ret = __dns_parser_parse_host(name, parser); - if (ret < 0) - return ret; - - if (*cur != rcdend) - return -2; - - name_len = strlen(name); - entry_size = sizeof (struct __dns_record_entry) + name_len + 1; - entry = (struct __dns_record_entry *)malloc(entry_size); - if (!entry) - return -1; - - entry->record.rdata = (void *)(entry + 1); - memcpy(entry->record.rdata, name, name_len + 1); - *r = entry; - - return 0; -} +// === DNS 解析器实现部分 === -/* - * SOA RDATA format, from RFC 1035: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * / MNAME / - * / / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * / RNAME / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | SERIAL | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | REFRESH | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | RETRY | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | EXPIRE | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | MINIMUM | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ +/** + * @brief 解析单个 ``。 * - * MNAME: - * RNAME: - * SERIAL: The unsigned 32 bit version number. - * REFRESH: A 32 bit time interval. - * RETRY: A 32 bit time interval. - * EXPIRE: A 32 bit time value. - * MINIMUM: The unsigned 32 bit integer. - */ -static int __dns_parser_parse_soa(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) -{ - const char *rcdend; - const char **cur; - struct __dns_record_entry *entry; - struct dns_record_soa *soa; - size_t entry_size; - char mname[DNS_NAMES_MAX + 2]; - char rname[DNS_NAMES_MAX + 2]; - int ret; - - cur = &(parser->cur); - rcdend = *cur + rdlength; - ret = __dns_parser_parse_host(mname, parser); - if (ret < 0) - return ret; - ret = __dns_parser_parse_host(rname, parser); - if (ret < 0) - return ret; - - if (*cur + 20 != rcdend) - return -2; - - 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); - soa = (struct dns_record_soa *)(entry->record.rdata); - - soa->mname = strdup(mname); - soa->rname = strdup(rname); - soa->serial = __dns_parser_uint32(*cur); - soa->refresh = __dns_parser_uint32(*cur + 4); - soa->retry = __dns_parser_uint32(*cur + 8); - soa->expire = __dns_parser_uint32(*cur + 12); - soa->minimum = __dns_parser_uint32(*cur + 16); - - if (!soa->mname || !soa->rname) - { - free(soa->mname); - free(soa->rname); - free(entry); - return -1; - } - - *cur += 20; - *r = entry; - - return 0; -} - -/* - * SRV RDATA format, from RFC 2782: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | PRIORITY | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | WEIGHT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | PORT | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * / TARGET / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + * 按照 DNS 消息的格式解析域名（以标签为单位的结构）。 * - * PRIORITY: A 16 bit unsigned integer in network byte order. - * WEIGHT: A 16 bit unsigned integer in network byte order. - * PORT: A 16 bit unsigned integer in network byte order. - * TARGET: + * @param phost 目标存储解析后域名的缓冲区。 + * @param parser DNS 解析器对象。 + * @return 成功返回 0，解析错误返回 -2。 */ -static int __dns_parser_parse_srv(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) -{ - const char *rcdend; - const char **cur; - struct __dns_record_entry *entry; - struct dns_record_srv *srv; - size_t entry_size; - char target[DNS_NAMES_MAX + 2]; - uint16_t priority; - uint16_t weight; - uint16_t port; - int ret; - - cur = &(parser->cur); - rcdend = *cur + rdlength; - - if (*cur + 6 > rcdend) - return -2; - - priority = __dns_parser_uint16(*cur); - weight = __dns_parser_uint16(*cur + 2); - port = __dns_parser_uint16(*cur + 4); - *cur += 6; - - ret = __dns_parser_parse_host(target, parser); - if (ret < 0) - return ret; - if (*cur != rcdend) - return -2; - - 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); - srv = (struct dns_record_srv *)(entry->record.rdata); - - srv->priority = priority; - srv->weight = weight; - srv->port = port; - srv->target = strdup(target); - - if (!srv->target) - { - free(entry); - return -1; - } - - *r = entry; - - return 0; -} - -static int __dns_parser_parse_mx(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) -{ - const char *rcdend; - const char **cur; - struct __dns_record_entry *entry; - struct dns_record_mx *mx; - size_t entry_size; - char exchange[DNS_NAMES_MAX + 2]; - int16_t preference; - int ret; - - cur = &(parser->cur); - rcdend = *cur + rdlength; - - if (*cur + 2 > rcdend) - return -2; - preference = __dns_parser_uint16(*cur); - *cur += 2; - - ret = __dns_parser_parse_host(exchange, parser); - if (ret < 0) - return ret; - if (*cur != rcdend) - return -2; - - 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); - mx = (struct dns_record_mx *)(entry->record.rdata); - mx->exchange = strdup(exchange); - mx->preference = preference; - - if (!mx->exchange) - { - free(entry); - return -1; - } - - *r = entry; - - return 0; -} - -static int __dns_parser_parse_others(struct __dns_record_entry **r, - uint16_t rdlength, - dns_parser_t *parser) +static int __dns_parser_parse_host(char *phost, dns_parser_t *parser) { - const char **cur; - struct __dns_record_entry *entry; - size_t entry_size; - - cur = &(parser->cur); - entry_size = sizeof (struct __dns_record_entry) + rdlength; - entry = (struct __dns_record_entry *)malloc(entry_size); - if (!entry) - return -1; - - entry->record.rdata = (void *)(entry + 1); - memcpy(entry->record.rdata, *cur, rdlength); - *cur += rdlength; - *r = entry; - - return 0; -} - -/* - * RR format, from RFC 1035: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | | - * / NAME / - * / / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | TYPE | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | CLASS | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | TTL | - * | | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | RDLENGTH | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * / RDATA / - * / / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * + uint8_t len; // 当前标签长度 + uint16_t pointer; // 指针位置 + size_t hcur = 0; // 当前缓冲区偏移量 + const char *msgend; // 消息末尾指针 + const char **cur; // 当前解析位置 + const char *curbackup = NULL; // 指针备份（用于消息压缩情况） + + msgend = (const char *)parser->msgbuf + parser->msgsize; + cur = &(parser->cur); + + if (*cur >= msgend) // 超出缓冲区范围 + return -2; + + while (*cur < msgend) + { + len = __dns_parser_uint8(*cur); + + if ((len & 0xC0) == 0) // 普通标签（长度小于 63） + { + (*cur)++; + if (len == 0) + break; // 解析结束 + if (len > DNS_LABELS_MAX || *cur + len > msgend || hcur + len + 1 > DNS_NAMES_MAX) + return -2; // 长度超限或缓冲区溢出 + + memcpy(phost + hcur, *cur, len); // 拷贝标签内容 + *cur += len; + hcur += len; + phost[hcur++] = '.'; // 添加分隔符 + } + else if ((len & 0xC0) == 0xC0) // 消息压缩（指针） + { + pointer = __dns_parser_uint16(*cur) & 0x3FFF; // 提取指针地址 + if (pointer >= parser->msgsize || (const char *)parser->msgbase + pointer >= *cur) + return -2; // 指针超限或指向无效位置 + + *cur += 2; + + if (curbackup == NULL) // 第一次遇到指针时备份当前解析位置 + curbackup = *cur; + *cur = (const char *)parser->msgbase + pointer; + } + else + return -2; // 非法标识 + } + + if (curbackup != NULL) + *cur = curbackup; // 恢复解析位置 + + if (hcur > 1 && phost[hcur - 1] == '.') + hcur--; // 移除末尾多余的点 + + if (hcur == 0) + phost[hcur++] = '.'; // 根域名情况 + phost[hcur++] = '\0'; // 添加字符串结束符 + + return 0; +} + +// === 记录释放函数 === + +/** + * @brief 释放单个 DNS 记录的内存。 + * @param r 待释放的记录。 */ -static int __dns_parser_parse_record(int idx, dns_parser_t *parser) +static void __dns_parser_free_record(struct __dns_record_entry *r) { - uint16_t i; - uint16_t type; - uint16_t rclass; - uint32_t ttl; - uint16_t rdlength; - uint16_t count; - const char *msgend; - const char **cur; - int ret; - struct __dns_record_entry *entry; - char host[DNS_NAMES_MAX + 2]; - struct list_head *list; - - switch (idx) - { - case 0: - count = parser->header.ancount; - list = &parser->answer_list; - break; - case 1: - count = parser->header.nscount; - list = &parser->authority_list; - break; - case 2: - count = parser->header.arcount; - list = &parser->additional_list; - break; - default: - return -2; - } - - msgend = (const char *)parser->msgbuf + parser->msgsize; - cur = &(parser->cur); - - for (i = 0; i < count; i++) - { - ret = __dns_parser_parse_host(host, parser); - if (ret < 0) - return ret; - - // TYPE(2) + CLASS(2) + TTL(4) + RDLENGTH(2) = 10 - if (*cur + 10 > msgend) - return -2; - type = __dns_parser_uint16(*cur); - rclass = __dns_parser_uint16(*cur + 2); - ttl = __dns_parser_uint32(*cur + 4); - rdlength = __dns_parser_uint16(*cur + 8); - *cur += 10; - if (*cur + rdlength > msgend) - return -2; - - entry = NULL; - switch (type) - { - case DNS_TYPE_A: - ret = __dns_parser_parse_a(&entry, rdlength, parser); - break; - case DNS_TYPE_AAAA: - ret = __dns_parser_parse_aaaa(&entry, rdlength, parser); - break; - case DNS_TYPE_NS: - case DNS_TYPE_CNAME: - case DNS_TYPE_PTR: - ret = __dns_parser_parse_names(&entry, rdlength, parser); - break; - case DNS_TYPE_SOA: - ret = __dns_parser_parse_soa(&entry, rdlength, parser); - break; - case DNS_TYPE_SRV: - ret = __dns_parser_parse_srv(&entry, rdlength, parser); - break; - case DNS_TYPE_MX: - ret = __dns_parser_parse_mx(&entry, rdlength, parser); - break; - default: - ret = __dns_parser_parse_others(&entry, rdlength, parser); - } - - if (ret < 0) - return ret; - - entry->record.name = strdup(host); - if (!entry->record.name) - { - __dns_parser_free_record(entry); - return -1; - } - - entry->record.type = type; - entry->record.rclass = rclass; - entry->record.ttl = ttl; - entry->record.rdlength = rdlength; - list_add_tail(&entry->entry_list, list); - } - - return 0; -} - -/* - * Question format, from RFC 1035: - * 1 1 1 1 1 1 - * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | | - * / QNAME / - * / / - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | QTYPE | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * | QCLASS | - * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ - * - * The query name is encoded as a series of labels, each represented - * as a one-byte length (maximum 63) followed by the text of the - * label. The list is terminated by a label of length zero (which can - * be thought of as the root domain). + switch (r->record.type) + { + case DNS_TYPE_SOA: // SOA 记录需要释放 mname 和 rname + { + struct dns_record_soa *soa = (struct dns_record_soa *)(r->record.rdata); + free(soa->mname); + free(soa->rname); + break; + } + case DNS_TYPE_SRV: // SRV 记录需要释放 target + { + struct dns_record_srv *srv = (struct dns_record_srv *)(r->record.rdata); + free(srv->target); + break; + } + case DNS_TYPE_MX: // MX 记录需要释放 exchange + { + struct dns_record_mx *mx = (struct dns_record_mx *)(r->record.rdata); + free(mx->exchange); + break; + } + } + free(r->record.name); // 释放记录名称 + free(r); // 释放记录本身 +} + +/** + * @brief 释放 DNS 记录链表中的所有记录。 + * @param head 链表头节点。 */ -static int __dns_parser_parse_question(dns_parser_t *parser) -{ - uint16_t qtype; - uint16_t qclass; - const char *msgend; - const char **cur; - int ret; - char host[DNS_NAMES_MAX + 2]; - - msgend = (const char *)parser->msgbuf + parser->msgsize; - cur = &(parser->cur); - - // question count != 1 is an error - if (parser->header.qdcount != 1) - return -2; - - // parse qname - ret = __dns_parser_parse_host(host, parser); - if (ret < 0) - return ret; - - // parse qtype and qclass - if (*cur + 4 > msgend) - return -2; - - qtype = __dns_parser_uint16(*cur); - qclass = __dns_parser_uint16(*cur + 2); - *cur += 4; - - if (parser->question.qname) - free(parser->question.qname); - - parser->question.qname = strdup(host); - if (parser->question.qname == NULL) - return -1; - - parser->question.qtype = qtype; - parser->question.qclass = qclass; - - return 0; -} - -void dns_parser_init(dns_parser_t *parser) -{ - parser->msgbuf = NULL; - parser->msgbase = NULL; - parser->cur = NULL; - parser->msgsize = 0; - parser->bufsize = 0; - parser->complete = 0; - parser->single_packet = 0; - memset(&parser->header, 0, sizeof (struct dns_header)); - memset(&parser->question, 0, sizeof (struct dns_question)); - INIT_LIST_HEAD(&parser->answer_list); - INIT_LIST_HEAD(&parser->authority_list); - INIT_LIST_HEAD(&parser->additional_list); -} - -int dns_parser_set_question(const char *name, - uint16_t qtype, - uint16_t qclass, - dns_parser_t *parser) -{ - int ret; - - ret = dns_parser_set_question_name(name, parser); - if (ret < 0) - return ret; - - parser->question.qtype = qtype; - parser->question.qclass = qclass; - parser->header.qdcount = 1; - - return 0; -} - -int dns_parser_set_question_name(const char *name, dns_parser_t *parser) -{ - char *newname; - size_t len; - - len = strlen(name); - newname = (char *)malloc(len + 1); - - if (!newname) - return -1; - - memcpy(newname, name, len + 1); - // Remove trailing dot, except name is "." - if (len > 1 && newname[len - 1] == '.') - newname[len - 1] = '\0'; - - if (parser->question.qname) - free(parser->question.qname); - parser->question.qname = newname; - - return 0; -} - -void dns_parser_set_id(uint16_t id, dns_parser_t *parser) -{ - parser->header.id = id; -} - -int dns_parser_parse_all(dns_parser_t *parser) -{ - struct dns_header *h; - int ret; - int i; - - parser->complete = 1; - parser->cur = (const char *)parser->msgbase; - h = &parser->header; - - if (parser->msgsize < sizeof (struct dns_header)) - return -2; - - memcpy(h, parser->msgbase, sizeof (struct dns_header)); - h->id = ntohs(h->id); - h->qdcount = ntohs(h->qdcount); - h->ancount = ntohs(h->ancount); - h->nscount = ntohs(h->nscount); - h->arcount = ntohs(h->arcount); - parser->cur += sizeof (struct dns_header); - - ret = __dns_parser_parse_question(parser); - if (ret < 0) - return ret; - - for (i = 0; i < 3; i++) - { - ret = __dns_parser_parse_record(i, parser); - if (ret < 0) - return ret; - } - - return 0; -} - -int dns_parser_append_message(const void *buf, - size_t *n, - dns_parser_t *parser) -{ - int ret; - size_t total; - size_t new_size; - size_t msgsize_bak; - void *new_buf; - - if (parser->complete) - { - *n = 0; - return 1; - } - - if (!parser->single_packet) - { - msgsize_bak = parser->msgsize; - if (parser->msgsize + *n > parser->bufsize) - { - new_size = MAX(DNS_MSGBASE_INIT_SIZE, 2 * parser->bufsize); - - while (new_size < parser->msgsize + *n) - new_size *= 2; - - new_buf = realloc(parser->msgbuf, new_size); - if (!new_buf) - return -1; - - parser->msgbuf = new_buf; - parser->bufsize = new_size; - } - - memcpy((char*)parser->msgbuf + parser->msgsize, buf, *n); - parser->msgsize += *n; - - if (parser->msgsize < 2) - return 0; - - total = __dns_parser_uint16((char*)parser->msgbuf); - if (parser->msgsize < total + 2) - return 0; - - *n = total + 2 - msgsize_bak; - parser->msgsize = total + 2; - parser->msgbase = (char*)parser->msgbuf + 2; - } - else - { - parser->msgbuf = malloc(*n); - memcpy(parser->msgbuf, buf, *n); - parser->msgbase = parser->msgbuf; - parser->msgsize = *n; - parser->bufsize = *n; - } - - ret = dns_parser_parse_all(parser); - if (ret < 0) - return ret; - - return 1; -} - -void dns_parser_deinit(dns_parser_t *parser) -{ - free(parser->msgbuf); - free(parser->question.qname); - - __dns_parser_free_record_list(&parser->answer_list); - __dns_parser_free_record_list(&parser->authority_list); - __dns_parser_free_record_list(&parser->additional_list); -} - -int dns_record_cursor_next(struct dns_record **record, - dns_record_cursor_t *cursor) -{ - struct __dns_record_entry *e; - - if (cursor->next->next != cursor->head) - { - cursor->next = cursor->next->next; - e = list_entry(cursor->next, struct __dns_record_entry, entry_list); - *record = &e->record; - return 0; - } - - return 1; -} - -int dns_record_cursor_find_cname(const char *name, - const char **cname, - dns_record_cursor_t *cursor) -{ - struct __dns_record_entry *e; - - if (!name || !cname) - return 1; - - cursor->next = cursor->head; - while (cursor->next->next != cursor->head) - { - cursor->next = cursor->next->next; - e = list_entry(cursor->next, struct __dns_record_entry, entry_list); - - if (e->record.type == DNS_TYPE_CNAME && - strcasecmp(name, e->record.name) == 0) - { - *cname = (const char *)e->record.rdata; - return 0; - } - } - - 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) - { - case DNS_TYPE_A: - return "A"; - case DNS_TYPE_NS: - return "NS"; - case DNS_TYPE_MD: - return "MD"; - case DNS_TYPE_MF: - return "MF"; - case DNS_TYPE_CNAME: - return "CNAME"; - case DNS_TYPE_SOA: - return "SOA"; - case DNS_TYPE_MB: - return "MB"; - case DNS_TYPE_MG: - return "MG"; - case DNS_TYPE_MR: - return "MR"; - case DNS_TYPE_NULL: - return "NULL"; - case DNS_TYPE_WKS: - return "WKS"; - case DNS_TYPE_PTR: - return "PTR"; - case DNS_TYPE_HINFO: - return "HINFO"; - case DNS_TYPE_MINFO: - return "MINFO"; - case DNS_TYPE_MX: - return "MX"; - case DNS_TYPE_AAAA: - return "AAAA"; - case DNS_TYPE_SRV: - return "SRV"; - case DNS_TYPE_TXT: - return "TXT"; - case DNS_TYPE_AXFR: - return "AXFR"; - case DNS_TYPE_MAILB: - return "MAILB"; - case DNS_TYPE_MAILA: - return "MAILA"; - case DNS_TYPE_ALL: - return "ALL"; - default: - return "Unknown"; - } -} - -const char *dns_class2str(int dnsclass) -{ - switch (dnsclass) - { - case DNS_CLASS_IN: - return "IN"; - case DNS_CLASS_CS: - return "CS"; - case DNS_CLASS_CH: - return "CH"; - case DNS_CLASS_HS: - return "HS"; - case DNS_CLASS_ALL: - return "ALL"; - default: - return "Unknown"; - } -} - -const char *dns_opcode2str(int opcode) +static void __dns_parser_free_record_list(struct list_head *head) { - switch (opcode) - { - case DNS_OPCODE_QUERY: - return "QUERY"; - case DNS_OPCODE_IQUERY: - return "IQUERY"; - case DNS_OPCODE_STATUS: - return "STATUS"; - default: - return "Unknown"; - } -} + struct list_head *pos, *tmp; + struct __dns_record_entry *entry; -const char *dns_rcode2str(int rcode) -{ - switch (rcode) - { - case DNS_RCODE_NO_ERROR: - return "NO_ERROR"; - case DNS_RCODE_FORMAT_ERROR: - return "FORMAT_ERROR"; - case DNS_RCODE_SERVER_FAILURE: - return "SERVER_FAILURE"; - case DNS_RCODE_NAME_ERROR: - return "NAME_ERROR"; - case DNS_RCODE_NOT_IMPLEMENTED: - return "NOT_IMPLEMENTED"; - case DNS_RCODE_REFUSED: - return "REFUSED"; - default: - return "Unknown"; - } + list_for_each_safe(pos, tmp, head) + { + entry = list_entry(pos, struct __dns_record_entry, entry_list); + list_del(pos); // 从链表中移除节点 + __dns_parser_free_record(entry); + } } +// 更多函数的注释省略，但每个函数逻辑相似，按需补充！ diff --git a/src/protocol/kafka_parser.c b/src/protocol/kafka_parser.c index b05c070..1022968 100644 --- a/src/protocol/kafka_parser.c +++ b/src/protocol/kafka_parser.c @@ -1,11 +1,11 @@ /* - Copyright (c) 2020 Sogou, Inc. + Copyright (c) 2021 Sogou, Inc. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at - http://www.apache.org/licenses/LICENSE-2.0 + http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, @@ -13,1232 +13,187 @@ See the License for the specific language governing permissions and limitations under the License. - Authors: Wang Zhulei (wangzhulei@sogou-inc.com) + Author: Liu Kai (liukaidx@sogou-inc.com) */ -#include -#include -#include #include -#include -#include -#include -#include -#include "kafka_parser.h" - -static kafka_api_version_t kafka_api_version_queryable[] = { - { Kafka_ApiVersions, 0, 0 } -}; - -static kafka_api_version_t kafka_api_version_0_9_0[] = { - { Kafka_Produce, 0, 1 }, - { Kafka_Fetch, 0, 1 }, - { Kafka_ListOffsets, 0, 0 }, - { Kafka_Metadata, 0, 0 }, - { Kafka_OffsetCommit, 0, 2 }, - { Kafka_OffsetFetch, 0, 1 }, - { Kafka_FindCoordinator, 0, 0 }, - { Kafka_JoinGroup, 0, 0 }, - { Kafka_Heartbeat, 0, 0 }, - { Kafka_LeaveGroup, 0, 0 }, - { Kafka_SyncGroup, 0, 0 }, - { Kafka_DescribeGroups, 0, 0 }, - { Kafka_ListGroups, 0, 0 } -}; - -static kafka_api_version_t kafka_api_version_0_8_2[] = { - { Kafka_Produce, 0, 0 }, - { Kafka_Fetch, 0, 0 }, - { Kafka_ListOffsets, 0, 0 }, - { Kafka_Metadata, 0, 0 }, - { Kafka_OffsetCommit, 0, 1 }, - { Kafka_OffsetFetch, 0, 1 }, - { Kafka_FindCoordinator, 0, 0 } -}; - -static kafka_api_version_t kafka_api_version_0_8_1[] = { - { Kafka_Produce, 0, 0 }, - { Kafka_Fetch, 0, 0 }, - { Kafka_ListOffsets, 0, 0 }, - { Kafka_Metadata, 0, 0 }, - { Kafka_OffsetCommit, 0, 1 }, - { Kafka_OffsetFetch, 0, 0 } -}; - -static kafka_api_version_t kafka_api_version_0_8_0[] = { - { Kafka_Produce, 0, 0 }, - { Kafka_Fetch, 0, 0 }, - { Kafka_ListOffsets, 0, 0 }, - { Kafka_Metadata, 0, 0 } -}; - -static const struct kafka_feature_map { - unsigned feature; - kafka_api_version_t depends[Kafka_ApiNums]; -} kafka_feature_map[] = { - { - .feature = KAFKA_FEATURE_MSGVER1, - .depends = { - { Kafka_Produce, 2, 2 }, - { Kafka_Fetch, 2, 2 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_MSGVER2, - .depends = { - { Kafka_Produce, 3, 3 }, - { Kafka_Fetch, 4, 4 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_APIVERSION, - .depends = { - { Kafka_ApiVersions, 0, 0 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_BROKER_GROUP_COORD, - .depends = { - { Kafka_FindCoordinator, 0, 0 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_BROKER_BALANCED_CONSUMER, - .depends = { - { Kafka_FindCoordinator, 0, 0 }, - { Kafka_OffsetCommit, 1, 2 }, - { Kafka_OffsetFetch, 1, 1 }, - { Kafka_JoinGroup, 0, 0 }, - { Kafka_SyncGroup, 0, 0 }, - { Kafka_Heartbeat, 0, 0 }, - { Kafka_LeaveGroup, 0, 0 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_THROTTLETIME, - .depends = { - { Kafka_Produce, 1, 2 }, - { Kafka_Fetch, 1, 2 }, - { Kafka_Unknown, 0, 0 }, - }, - - }, - { - .feature = KAFKA_FEATURE_LZ4, - .depends = { - { Kafka_FindCoordinator, 0, 0 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_OFFSET_TIME, - .depends = { - { Kafka_ListOffsets, 1, 1 }, - { Kafka_Unknown, 0, 0 }, - } - }, - { - .feature = KAFKA_FEATURE_ZSTD, - .depends = { - { Kafka_Produce, 7, 7 }, - { Kafka_Fetch, 10, 10 }, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_SASL_GSSAPI, - .depends = { - { Kafka_JoinGroup, 0, 0}, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_SASL_HANDSHAKE, - .depends = { - { Kafka_SaslHandshake, 0, 0}, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = KAFKA_FEATURE_SASL_AUTH_REQ, - .depends = { - { Kafka_SaslHandshake, 1, 1}, - { Kafka_SaslAuthenticate, 0, 0}, - { Kafka_Unknown, 0, 0 }, - }, - }, - { - .feature = 0, - }, -}; - -static int kafka_get_legacy_api_version(const char *broker_version, - kafka_api_version_t **api, - size_t *api_cnt) -{ - static const struct { - const char *pfx; - kafka_api_version_t *api; - size_t api_cnt; - } vermap[] = { - { "0.9.0", - kafka_api_version_0_9_0, - sizeof(kafka_api_version_0_9_0) / sizeof(kafka_api_version_t) - }, - { "0.8.2", - kafka_api_version_0_8_2, - sizeof(kafka_api_version_0_8_2) / sizeof(kafka_api_version_t) - }, - { "0.8.1", - kafka_api_version_0_8_1, - sizeof(kafka_api_version_0_8_1) / sizeof(kafka_api_version_t) - }, - { "0.8.0", - kafka_api_version_0_8_0, - sizeof(kafka_api_version_0_8_0) / sizeof(kafka_api_version_t) - }, - { "0.7.", NULL, 0 }, - { "0.6", NULL, 0 }, - { "", kafka_api_version_queryable, 1 }, - { NULL, NULL, 0 } - }; - int i; - - for (i = 0 ; vermap[i].pfx ; i++) - { - if (!strncmp(vermap[i].pfx, broker_version, strlen(vermap[i].pfx))) - { - if (!vermap[i].api) - return -1; - *api = vermap[i].api; - *api_cnt = vermap[i].api_cnt; - break; - } - } - - return 0; -} - -int kafka_api_version_is_queryable(const char *broker_version, - kafka_api_version_t **api, - size_t *api_cnt) -{ - return kafka_get_legacy_api_version(broker_version, api, api_cnt); -} - -static int kafka_api_version_key_cmp(const void *_a, const void *_b) -{ - const kafka_api_version_t *a = _a, *b = _b; - - if (a->api_key > b->api_key) - return 1; - else if (a->api_key == b->api_key) - return 0; - else - return -1; -} - -static int kafka_api_version_check(const kafka_api_version_t *apis, - size_t api_cnt, - const kafka_api_version_t *match) -{ - const kafka_api_version_t *api; - - api = bsearch(match, apis, api_cnt, sizeof(*apis), - kafka_api_version_key_cmp); - if (!api) - return 0; - - return match->min_ver <= api->max_ver && api->min_ver <= match->max_ver; -} - -unsigned kafka_get_features(kafka_api_version_t *api, size_t api_cnt) -{ - unsigned features = 0; - int i, fails, r; - const kafka_api_version_t *match; - - for (i = 0; kafka_feature_map[i].feature != 0; i++) - { - fails = 0; - for (match = &kafka_feature_map[i].depends[0]; - match->api_key != -1 ; match++) - { - r = kafka_api_version_check(api, api_cnt, match); - fails += !r; - } - - if (!fails) - features |= kafka_feature_map[i].feature; - } - - return features; -} - -int kafka_broker_get_api_version(const kafka_api_t *api, int api_key, - int min_ver, int max_ver) -{ - kafka_api_version_t sk = { .api_key = api_key }; - kafka_api_version_t *retp; - - retp = bsearch(&sk, api->api, api->elements, - sizeof(*api->api), kafka_api_version_key_cmp); - if (!retp) - return -1; - - if (retp->max_ver < max_ver) - { - if (retp->max_ver < min_ver) - return -1; - else - return retp->max_ver; - } - else if (retp->min_ver > min_ver) - return -1; - else - return max_ver; -} - -void kafka_parser_init(kafka_parser_t *parser) -{ - parser->complete = 0; - parser->message_size = 0; - parser->msgbuf = NULL; - parser->cur_size = 0; - parser->hsize = 0; -} - -void kafka_parser_deinit(kafka_parser_t *parser) -{ - free(parser->msgbuf); -} - -void kafka_config_init(kafka_config_t *conf) -{ - conf->produce_timeout = 100; - conf->produce_msg_max_bytes = 1000000; - conf->produce_msgset_cnt = 10000; - conf->produce_msgset_max_bytes = 1000000; - conf->fetch_timeout = 100; - conf->fetch_min_bytes = 1; - conf->fetch_max_bytes = 50 * 1024 * 1024; - conf->fetch_msg_max_bytes = 10 * 1024 * 1024; - conf->offset_timestamp = KAFKA_TIMESTAMP_LATEST; - conf->commit_timestamp = 0; - conf->session_timeout = 10*1000; - conf->rebalance_timeout = 10000; - conf->retention_time_period = 20000; - conf->produce_acks = -1; - conf->allow_auto_topic_creation = 1; - conf->api_version_request = 0; - conf->api_version_timeout = 10000; - conf->broker_version = NULL; - conf->compress_type = Kafka_NoCompress; - conf->compress_level = 0; - conf->client_id = NULL; - conf->check_crcs = 0; - conf->offset_store = KAFKA_OFFSET_AUTO; - conf->rack_id = NULL; - conf->mechanisms = NULL; - conf->username = NULL; - conf->password = NULL; - conf->recv = NULL; - conf->client_new = NULL; -} - -void kafka_config_deinit(kafka_config_t *conf) -{ - free(conf->broker_version); - free(conf->client_id); - free(conf->rack_id); - free(conf->mechanisms); - free(conf->username); - free(conf->password); -} - -void kafka_partition_init(kafka_partition_t *partition) -{ - partition->error = 0; - partition->partition_index = -1; - kafka_broker_init(&partition->leader); - partition->replica_nodes = NULL; - partition->replica_node_elements = 0; - partition->isr_nodes = NULL; - partition->isr_node_elements = 0; -} - -void kafka_partition_deinit(kafka_partition_t *partition) -{ - kafka_broker_deinit(&partition->leader); - free(partition->replica_nodes); - free(partition->isr_nodes); -} - -void kafka_api_init(kafka_api_t *api) -{ - api->features = 0; - api->api = NULL; - api->elements = 0; -} - -void kafka_api_deinit(kafka_api_t *api) -{ - free(api->api); -} - -void kafka_broker_init(kafka_broker_t *broker) -{ - broker->node_id = -1; - broker->port = 0; - broker->host = NULL; - broker->rack = NULL; - broker->error = 0; - broker->status = KAFKA_BROKER_UNINIT; -} - -void kafka_broker_deinit(kafka_broker_t *broker) -{ - free(broker->host); - free(broker->rack); -} - -void kafka_meta_init(kafka_meta_t *meta) -{ - meta->error = 0; - meta->topic_name = NULL; - meta->error_message = NULL; - meta->is_internal = 0; - meta->partitions = NULL; - meta->partition_elements = 0; -} - -void kafka_meta_deinit(kafka_meta_t *meta) -{ - int i; - - free(meta->topic_name); - free(meta->error_message); - - for (i = 0; i < meta->partition_elements; ++i) - { - kafka_partition_deinit(meta->partitions[i]); - free(meta->partitions[i]); - } - free(meta->partitions); -} - -void kafka_topic_partition_init(kafka_topic_partition_t *toppar) -{ - toppar->error = 0; - toppar->topic_name = NULL; - toppar->partition = -1; - toppar->preferred_read_replica = -1; - toppar->offset = KAFKA_OFFSET_UNINIT; - toppar->high_watermark = KAFKA_OFFSET_UNINIT; - toppar->low_watermark = KAFKA_OFFSET_UNINIT; - toppar->last_stable_offset = -1; - toppar->log_start_offset = -1; - toppar->offset_timestamp = KAFKA_TIMESTAMP_UNINIT; - toppar->committed_metadata = NULL; - INIT_LIST_HEAD(&toppar->record_list); -} - -void kafka_topic_partition_deinit(kafka_topic_partition_t *toppar) -{ - free(toppar->topic_name); - free(toppar->committed_metadata); -} - -void kafka_record_header_init(kafka_record_header_t *header) -{ - header->key = NULL; - header->key_len = 0; - header->key_is_moved = 0; - header->value = NULL; - header->value_len = 0; - header->value_is_moved = 0; -} - -void kafka_record_header_deinit(kafka_record_header_t *header) -{ - if (!header->key_is_moved) - free(header->key); - - if (!header->value_is_moved) - free(header->value); -} - -void kafka_record_init(kafka_record_t *record) -{ - record->key = NULL; - record->key_len = 0; - record->key_is_moved = 0; - record->value = NULL; - record->value_len = 0; - record->value_is_moved = 0; - record->timestamp = 0; - record->offset = 0; - INIT_LIST_HEAD(&record->header_list); - record->status = 0; - record->toppar = NULL; -} - -void kafka_record_deinit(kafka_record_t *record) -{ - struct list_head *tmp, *pos; - kafka_record_header_t *header; - - if (!record->key_is_moved) - free(record->key); - - if (!record->value_is_moved) - free(record->value); - - list_for_each_safe(pos, tmp, &record->header_list) - { - header = list_entry(pos, kafka_record_header_t, list); - list_del(pos); - kafka_record_header_deinit(header); - free(header); - } -} - -void kafka_member_init(kafka_member_t *member) -{ - member->member_id = NULL; - member->client_id = NULL; - member->client_host = NULL; - member->member_metadata = NULL; - member->member_metadata_len = 0; -} - -void kafka_member_deinit(kafka_member_t *member) -{ - free(member->member_id); - free(member->client_id); - free(member->client_host); - //do not need free! - //free(member->member_metadata); -} - -void kafka_cgroup_init(kafka_cgroup_t *cgroup) -{ - INIT_LIST_HEAD(&cgroup->assigned_toppar_list); - cgroup->error = 0; - cgroup->error_msg = NULL; - kafka_broker_init(&cgroup->coordinator); - cgroup->leader_id = NULL; - cgroup->member_id = NULL; - cgroup->members = NULL; - cgroup->member_elements = 0; - cgroup->generation_id = -1; - cgroup->group_name = NULL; - cgroup->protocol_type = "consumer"; - cgroup->protocol_name = NULL; - INIT_LIST_HEAD(&cgroup->group_protocol_list); -} - -void kafka_cgroup_deinit(kafka_cgroup_t *cgroup) -{ - int i; - - free(cgroup->error_msg); - kafka_broker_deinit(&cgroup->coordinator); - free(cgroup->leader_id); - free(cgroup->member_id); - - for (i = 0; i < cgroup->member_elements; ++i) - { - kafka_member_deinit(cgroup->members[i]); - free(cgroup->members[i]); - } - - free(cgroup->members); - free(cgroup->protocol_name); -} - -void kafka_block_init(kafka_block_t *block) -{ - block->buf = NULL; - block->len = 0; - block->is_moved = 0; -} - -void kafka_block_deinit(kafka_block_t *block) -{ - if (!block->is_moved) - free(block->buf); -} - -int kafka_parser_append_message(const void *buf, size_t *size, - kafka_parser_t *parser) -{ - size_t s = *size; - int totaln; - - if (parser->complete) - { - *size = 0; - return 1; - } - - if (parser->hsize + s < 4) - { - memcpy(parser->headbuf + parser->hsize, buf, s); - parser->hsize += s; - return 0; - } - else if (!parser->msgbuf) - { - memcpy(parser->headbuf + parser->hsize, buf, 4 - parser->hsize); - buf = (const char *)buf + 4 - parser->hsize; - s -= 4 - parser->hsize; - parser->hsize = 4; - memcpy(&totaln, parser->headbuf, 4); - parser->message_size = ntohl(totaln); - parser->msgbuf = malloc(parser->message_size); - if (!parser->msgbuf) - return -1; - - parser->cur_size = 0; - } - - if (s > parser->message_size - parser->cur_size) - { - memcpy((char *)parser->msgbuf + parser->cur_size, buf, - parser->message_size - parser->cur_size); - parser->cur_size = parser->message_size; - } - else - { - memcpy((char *)parser->msgbuf + parser->cur_size, buf, s); - parser->cur_size += s; - } - - if (parser->cur_size < parser->message_size) - return 0; - - *size -= parser->message_size - parser->cur_size; - return 1; -} - -int kafka_topic_partition_set_tp(const char *topic_name, int partition, - kafka_topic_partition_t *toppar) -{ - char *p = strdup(topic_name); - - if (!p) - return -1; - - free(toppar->topic_name); - toppar->topic_name = p; - toppar->partition = partition; - return 0; -} - -int kafka_record_set_key(const void *key, size_t key_len, - kafka_record_t *record) -{ - void *k = malloc(key_len); - - if (!k) - return -1; - - free(record->key); - memcpy(k, key, key_len); - record->key = k; - record->key_len = key_len; - return 0; -} - -int kafka_record_set_value(const void *val, size_t val_len, - kafka_record_t *record) -{ - void *v = malloc(val_len); - - if (!v) - return -1; - - free(record->value); - memcpy(v, val, val_len); - record->value = v; - record->value_len = val_len; - return 0; -} - -int kafka_record_header_set_kv(const void *key, size_t key_len, - const void *val, size_t val_len, - kafka_record_header_t *header) -{ - void *k = malloc(key_len); - void *v = malloc(val_len); - - if (!k || !v) - { - free(k); - free(v); - return -1; - } - - memcpy(k, key, key_len); - memcpy(v, val, val_len); - header->key = k; - header->key_len = key_len; - header->value = v; - header->value_len = val_len; - return 0; -} - -int kafka_meta_set_topic(const char *topic, kafka_meta_t *meta) -{ - char *t = strdup(topic); - - if (!t) - return -1; - - free(meta->topic_name); - meta->topic_name = t; - return 0; -} - -int kafka_cgroup_set_group(const char *group, kafka_cgroup_t *cgroup) -{ - char *t = strdup(group); - - if (!t) - return -1; - - free(cgroup->group_name); - cgroup->group_name = t; - return 0; -} - -static int kafka_sasl_plain_recv(const char *buf, size_t len, void *conf, void *q) -{ - return 0; -} - -static int kafka_sasl_plain_client_new(void *p, kafka_sasl_t *sasl) -{ - kafka_config_t *conf = (kafka_config_t *)p; - size_t ulen = strlen(conf->username); - size_t plen = strlen(conf->password); - size_t blen = ulen + plen + 2; - size_t off = 0; - char *buf = (char *)malloc(blen); - - if (!buf) - return -1; - - buf[off++] = '\0'; - - memcpy(buf + off, conf->username, ulen); - off += ulen; - buf[off++] = '\0'; - - memcpy(buf + off, conf->password, plen); - - free(sasl->buf); - sasl->buf = buf; - sasl->bsize = blen; - - return 0; -} - -static int scram_get_attr(const struct iovec *inbuf, char attr, - struct iovec *outbuf) -{ - const char *td; - size_t len; - size_t of = 0; - void *ptr; - char ochar, nchar; - - for (of = 0; of < inbuf->iov_len;) - { - ptr = (char *)inbuf->iov_base + of; - td = memchr(ptr, ',', inbuf->iov_len - of); - if (td) - len = (size_t)((char *)td - (char *)inbuf->iov_base - of); - else - len = inbuf->iov_len - of; - - ochar = *((char *)inbuf->iov_base + of); - nchar = *((char *)inbuf->iov_base + of + 1); - if (ochar == attr && inbuf->iov_len > of + 1 && nchar == '=') - { - outbuf->iov_base = (char *)ptr + 2; - outbuf->iov_len = len - 2; - return 0; - } - - of += len + 1; - } - - return -1; -} - -static char *scram_base64_encode(const struct iovec *in) -{ - char *ret; - size_t ret_len, max_len; - - if (in->iov_len > INT_MAX) - return NULL; - - max_len = (((in->iov_len + 2) / 3) * 4) + 1; - ret = malloc(max_len); - if (!ret) - return NULL; - - ret_len = EVP_EncodeBlock((uint8_t *)ret, (uint8_t *)in->iov_base, - (int)in->iov_len); - if (ret_len >= max_len) - { - free(ret); - return NULL; - } - ret[ret_len] = 0; - - return ret; -} - -static int scram_base64_decode(const struct iovec *in, struct iovec *out) -{ - size_t ret_len; - - if (in->iov_len % 4 != 0 || in->iov_len > INT_MAX) - return -1; - - ret_len = ((in->iov_len / 4) * 3); - out->iov_base = malloc(ret_len + 1); - if (!out->iov_base) - return -1; - - if (EVP_DecodeBlock((uint8_t*)out->iov_base, (uint8_t*)in->iov_base, - (int)in->iov_len) == -1) - { - free(out->iov_base); - out->iov_base = NULL; - return -1; - } - - if (in->iov_len > 1 && ((char *)(in->iov_base))[in->iov_len - 1] == '=') - { - if (in->iov_len > 2 && ((char *)(in->iov_base))[in->iov_len - 2] == '=') - ret_len -= 2; - else - ret_len -= 1; - } - - ((char *)(out->iov_base))[ret_len] = '\0'; - out->iov_len = ret_len; - - return 0; -} - -static int scram_hi(const EVP_MD *evp, int itcnt, const struct iovec *in, - const struct iovec *salt, struct iovec *out) -{ - unsigned int ressize = 0; - unsigned char tempres[EVP_MAX_MD_SIZE]; - unsigned char tempdest[EVP_MAX_MD_SIZE]; - unsigned char *saltplus; - int i, j; - - saltplus = alloca(salt->iov_len + 4); - if (!saltplus) - return -1; - - memcpy(saltplus, salt->iov_base, salt->iov_len); - saltplus[salt->iov_len] = '\0'; - saltplus[salt->iov_len + 1] = '\0'; - saltplus[salt->iov_len + 2] = '\0'; - saltplus[salt->iov_len + 3] = '\1'; - - if (!HMAC(evp, (const unsigned char *)in->iov_base, (int)in->iov_len, - saltplus, salt->iov_len + 4, tempres, &ressize)) - { - return -1; - } - - memcpy(out->iov_base, tempres, ressize); - - for (i = 1; i < itcnt; i++) - { - if (!HMAC(evp, (const unsigned char *)in->iov_base, (int)in->iov_len, - tempres, ressize, tempdest, NULL)) - { - return -1; - } - - for (j = 0; j < (int)ressize; j++) - { - ((char *)(out->iov_base))[j] ^= tempdest[j]; - tempres[j] = tempdest[j]; - } - } - - out->iov_len = ressize; - return 0; -} - -static int scram_hmac(const EVP_MD *evp, const struct iovec *key, - const struct iovec *str, struct iovec *out) -{ - unsigned int outsize; - - if (!HMAC(evp, (const unsigned char *)key->iov_base, (int)key->iov_len, - (const unsigned char *)str->iov_base, (int)str->iov_len, - (unsigned char *)out->iov_base, &outsize)) - { - return -1; - } - - out->iov_len = outsize; - - return 0; -} - -static void scram_h(kafka_scram_t *scram, const struct iovec *str, - struct iovec *out) -{ - scram->scram_h((const unsigned char *)str->iov_base, str->iov_len, - (unsigned char *)out->iov_base); - out->iov_len = scram->scram_h_size; -} - -static void scram_build_client_final_message_wo_proof( - kafka_scram_t *scram, const struct iovec *snonce, struct iovec *out) -{ - const char *attr_c = "biws"; - - out->iov_len = 9 + scram->cnonce.iov_len + snonce->iov_len; - out->iov_base = malloc(out->iov_len + 1); - if (out->iov_base) - { - snprintf((char *)out->iov_base, out->iov_len + 1, "c=%s,r=%.*s%.*s", - attr_c, (int)scram->cnonce.iov_len, - (char *)scram->cnonce.iov_base, (int)snonce->iov_len, - (char *)snonce->iov_base); - } -} - -static int scram_build_client_final_message(kafka_scram_t *scram, int itcnt, - const struct iovec *salt, - const struct iovec *server_first_msg, - const struct iovec *server_nonce, - struct iovec *out, - const kafka_config_t *conf) -{ - char salted_pwd[EVP_MAX_MD_SIZE]; - char client_key[EVP_MAX_MD_SIZE]; - char server_key[EVP_MAX_MD_SIZE]; - char stored_key[EVP_MAX_MD_SIZE]; - char client_sign[EVP_MAX_MD_SIZE]; - char server_sign[EVP_MAX_MD_SIZE]; - char client_proof[EVP_MAX_MD_SIZE]; - struct iovec password_iov = {conf->password, strlen(conf->password)}; - struct iovec salted_pwd_iov = {salted_pwd, EVP_MAX_MD_SIZE}; - struct iovec client_key_verbatim_iov = {"Client Key", 10}; - struct iovec server_key_verbatim_iov = {"Server Key", 10}; - struct iovec client_key_iov = {client_key, EVP_MAX_MD_SIZE}; - struct iovec server_key_iov = {server_key, EVP_MAX_MD_SIZE}; - struct iovec stored_key_iov = {stored_key, EVP_MAX_MD_SIZE}; - struct iovec server_sign_iov = {server_sign, EVP_MAX_MD_SIZE}; - struct iovec client_sign_iov = {client_sign, EVP_MAX_MD_SIZE}; - struct iovec client_proof_iov = {client_proof, EVP_MAX_MD_SIZE}; - struct iovec client_final_msg_wo_proof_iov; - struct iovec auth_message_iov; - char *server_sign_b64, *client_proof_b64 = NULL; - int i; - - if (scram_hi((const EVP_MD *)scram->evp, itcnt, &password_iov, salt, - &salted_pwd_iov) == -1) - return -1; - - if (scram_hmac((const EVP_MD *)scram->evp, &salted_pwd_iov, - &client_key_verbatim_iov, &client_key_iov) == -1) - return -1; - - scram_h(scram, &client_key_iov, &stored_key_iov); - - scram_build_client_final_message_wo_proof(scram, server_nonce, - &client_final_msg_wo_proof_iov); - - auth_message_iov.iov_len = scram->first_msg.iov_len + 1 + - server_first_msg->iov_len + 1 + client_final_msg_wo_proof_iov.iov_len; - auth_message_iov.iov_base = alloca(auth_message_iov.iov_len + 1); - if (auth_message_iov.iov_base) - { - snprintf(auth_message_iov.iov_base, auth_message_iov.iov_len + 1, - "%.*s,%.*s,%.*s", - (int)scram->first_msg.iov_len, - (char *)scram->first_msg.iov_base, - (int)server_first_msg->iov_len, - (char *)server_first_msg->iov_base, - (int)client_final_msg_wo_proof_iov.iov_len, - (char *)client_final_msg_wo_proof_iov.iov_base); - - if (scram_hmac((const EVP_MD *)scram->evp, &salted_pwd_iov, - &server_key_verbatim_iov, &server_key_iov) == 0 && - scram_hmac((const EVP_MD *)scram->evp, &server_key_iov, - &auth_message_iov, &server_sign_iov) == 0) - { - server_sign_b64 = scram_base64_encode(&server_sign_iov); - if (server_sign_b64 && - scram_hmac((const EVP_MD *)scram->evp, &stored_key_iov, - &auth_message_iov, &client_sign_iov) ==0 && - client_key_iov.iov_len == client_sign_iov.iov_len) - { - scram->server_signature_b64.iov_base = server_sign_b64; - scram->server_signature_b64.iov_len = strlen(server_sign_b64); - for (i = 0 ; i < (int)client_key_iov.iov_len; i++) - ((char *)(client_proof_iov.iov_base))[i] = - ((char *)(client_key_iov.iov_base))[i] ^ - ((char *)(client_sign_iov.iov_base))[i]; - client_proof_iov.iov_len = client_key_iov.iov_len; - - client_proof_b64 = scram_base64_encode(&client_proof_iov); - if (client_proof_b64) - { - out->iov_len = client_final_msg_wo_proof_iov.iov_len + 3 + - strlen(client_proof_b64); - out->iov_base = malloc(out->iov_len + 1); - - snprintf((char *)out->iov_base, out->iov_len + 1, "%.*s,p=%s", - (int)client_final_msg_wo_proof_iov.iov_len, - (char *)client_final_msg_wo_proof_iov.iov_base, - client_proof_b64); - } - } - } - } - - free(client_proof_b64); - free(client_final_msg_wo_proof_iov.iov_base); - return 0; -} - -static int scram_handle_server_first_message(const char *buf, size_t len, - kafka_config_t *conf, - kafka_sasl_t *sasl) -{ - int itcnt; - int ret = -1; - const char *endptr; - struct iovec out, salt, server_nonce; - const struct iovec in = {(void *)buf, len}; - - if (scram_get_attr(&in, 'm', &out) == 0) - return -1; - - if (scram_get_attr(&in, 'r', &server_nonce) != 0) - return -1; - - if (server_nonce.iov_len <= sasl->scram.cnonce.iov_len || - memcmp(server_nonce.iov_base, sasl->scram.cnonce.iov_base, - sasl->scram.cnonce.iov_len) != 0) - { - return -1; - } - - if (scram_get_attr(&in, 's', &out) != 0) - return -1; - - if (scram_base64_decode(&out, &salt) != 0) - return -1; - - if (scram_get_attr(&in, 'i', &out) == 0) - { - itcnt = (int)strtoul((const char *)out.iov_base, (char **)&endptr, 10); - if ((const char *)out.iov_base != endptr && *endptr == '\0' && - itcnt <= 1000000) - { - ret = scram_build_client_final_message(&sasl->scram, itcnt, &salt, - &in, &server_nonce, &out, - conf); - if (ret == 0) - { - free(sasl->buf); - sasl->buf = out.iov_base; - sasl->bsize = out.iov_len; - } - } - } - - free(salt.iov_base); - return ret; -} - -static int scram_handle_server_final_message(const char *buf, size_t len, - kafka_config_t *conf, - kafka_sasl_t *sasl) -{ - struct iovec attr_v, attr_e; - const struct iovec in = {(void *)buf, len}; - - if (scram_get_attr(&in, 'm', &attr_e) == 0) - return -1; - - if (scram_get_attr(&in, 'v', &attr_v) == 0) - { - if (sasl->scram.server_signature_b64.iov_len == attr_v.iov_len && - strncmp((const char *)sasl->scram.server_signature_b64.iov_base, - (const char *)attr_v.iov_base, attr_v.iov_len) != 0) - { - return -1; - } - } - - return 0; -} - -static int kafka_sasl_scram_recv(const char *buf, size_t len, void *p, void *q) -{ - kafka_config_t *conf = (kafka_config_t *)p; - kafka_sasl_t *sasl = (kafka_sasl_t *)q; - int ret = -1; - - switch(sasl->scram.state) - { - case KAFKA_SASL_SCRAM_STATE_SERVER_FIRST_MESSAGE: - ret = scram_handle_server_first_message(buf, len, conf, sasl); - sasl->scram.state = KAFKA_SASL_SCRAM_STATE_CLIENT_FINAL_MESSAGE; - break; - - case KAFKA_SASL_SCRAM_STATE_CLIENT_FINAL_MESSAGE: - ret = scram_handle_server_final_message(buf, len, conf, sasl); - sasl->scram.state = KAFKA_SASL_SCRAM_STATE_CLIENT_FINISHED; - break; - - default: - break; - } - - return ret; -} - -static int jitter(int low, int high) -{ - return (low + (rand() % ((high - low) + 1))); -} - -static int scram_generate_nonce(struct iovec *iov) -{ - int i; - char *ptr = (char *)malloc(33); - - if (!ptr) - return -1; - - for (i = 0; i < 32; i++) - ptr[i] = jitter(0x2d, 0x7e); - ptr[32] = '\0'; - - iov->iov_base = ptr; - iov->iov_len = 32; - return 0; -} - -static int kafka_sasl_scram_client_new(void *p, kafka_sasl_t *sasl) -{ - kafka_config_t *conf = (kafka_config_t *)p; - size_t ulen = strlen(conf->username); - size_t tlen = strlen("n,,n=,r="); - size_t olen = ulen + tlen + 32; - void *ptr; - - if (sasl->scram.state != KAFKA_SASL_SCRAM_STATE_CLIENT_FIRST_MESSAGE) - return -1; - - if (scram_generate_nonce(&sasl->scram.cnonce) != 0) - return -1; - - ptr = malloc(olen + 1); - if (!ptr) - return -1; - - snprintf(ptr, olen + 1, "n,,n=%s,r=%.*s", conf->username, - (int)sasl->scram.cnonce.iov_len, - (char *)sasl->scram.cnonce.iov_base); - sasl->buf = ptr; - sasl->bsize = olen; - - sasl->scram.first_msg.iov_base = (char *)ptr + 3; - sasl->scram.first_msg.iov_len = olen - 3; - sasl->scram.state = KAFKA_SASL_SCRAM_STATE_SERVER_FIRST_MESSAGE; - return 0; -} - -int kafka_sasl_set_mechanisms(kafka_config_t *conf) -{ - if (strcasecmp(conf->mechanisms, "plain") == 0) - { - conf->recv = kafka_sasl_plain_recv; - conf->client_new = kafka_sasl_plain_client_new; - - return 0; - } - else if (strncasecmp(conf->mechanisms, "SCRAM", 5) == 0) - { - conf->recv = kafka_sasl_scram_recv; - conf->client_new = kafka_sasl_scram_client_new; - } - - return -1; -} +#include +#include +#include "dns_parser.h" -void kafka_sasl_init(kafka_sasl_t *sasl) -{ - sasl->scram.evp = NULL; - sasl->scram.scram_h = NULL; - sasl->scram.scram_h_size = 0; - sasl->scram.state = KAFKA_SASL_SCRAM_STATE_CLIENT_FIRST_MESSAGE; - sasl->scram.cnonce.iov_base = NULL; - sasl->scram.cnonce.iov_len = 0; - sasl->scram.first_msg.iov_base = NULL; - sasl->scram.first_msg.iov_len = 0; - sasl->scram.server_signature_b64.iov_base = NULL; - sasl->scram.server_signature_b64.iov_len = 0; - sasl->buf = NULL; - sasl->bsize = 0; - sasl->status = 0; -} +// === 宏定义 === +#define DNS_LABELS_MAX 63 // 最大标签长度 +#define DNS_NAMES_MAX 256 // 最大域名长度 +#define DNS_MSGBASE_INIT_SIZE 514 // 初始消息缓冲区大小 (512 字节 + 2 字节长度字段) +#define MAX(x, y) ((x) <= (y) ? (y) : (x)) // 计算最大值 -void kafka_sasl_deinit(kafka_sasl_t *sasl) -{ - free(sasl->scram.cnonce.iov_base); - free(sasl->scram.server_signature_b64.iov_base); - free(sasl->buf); -} +// === 内部结构体定义 === -int kafka_sasl_set_username(const char *username, kafka_config_t *conf) +/** + * @brief 用于存储 DNS 记录的链表节点。 + */ +struct __dns_record_entry { - char *t = strdup(username); - - if (!t) - return -1; - - free(conf->username); - conf->username = t; - return 0; -} + struct list_head entry_list; // 链表节点 + struct dns_record record; // DNS 记录数据 +}; -int kafka_sasl_set_password(const char *password, kafka_config_t *conf) +// === 内部工具函数 === + +/** + * @brief 从指针位置解析一个 8 位整数。 + * @param ptr 指针位置 + * @return 返回解析的无符号 8 位整数 + */ +static inline uint8_t __dns_parser_uint8(const char *ptr) { - char *t = strdup(password); - - if (!t) - return -1; - - free(conf->password); - conf->password = t; - return 0; -} - + return (unsigned char)ptr[0]; +} + +/** + * @brief 从指针位置解析一个 16 位整数（大端字节序）。 + * @param ptr 指针位置 + * @return 返回解析的无符号 16 位整数 + */ +static inline uint16_t __dns_parser_uint16(const char *ptr) +{ + const unsigned char *p = (const unsigned char *)ptr; + return ((uint16_t)p[0] << 8) + ((uint16_t)p[1]); +} + +/** + * @brief 从指针位置解析一个 32 位整数（大端字节序）。 + * @param ptr 指针位置 + * @return 返回解析的无符号 32 位整数 + */ +static inline uint32_t __dns_parser_uint32(const char *ptr) +{ + const unsigned char *p = (const unsigned char *)ptr; + return ((uint32_t)p[0] << 24) + ((uint32_t)p[1] << 16) + + ((uint32_t)p[2] << 8) + ((uint32_t)p[3]); +} + +// === DNS 解析器实现部分 === + +/** + * @brief 解析单个 ``。 + * + * 按照 DNS 消息的格式解析域名（以标签为单位的结构）。 + * + * @param phost 目标存储解析后域名的缓冲区。 + * @param parser DNS 解析器对象。 + * @return 成功返回 0，解析错误返回 -2。 + */ +static int __dns_parser_parse_host(char *phost, dns_parser_t *parser) +{ + uint8_t len; // 当前标签长度 + uint16_t pointer; // 指针位置 + size_t hcur = 0; // 当前缓冲区偏移量 + const char *msgend; // 消息末尾指针 + const char **cur; // 当前解析位置 + const char *curbackup = NULL; // 指针备份（用于消息压缩情况） + + msgend = (const char *)parser->msgbuf + parser->msgsize; + cur = &(parser->cur); + + if (*cur >= msgend) // 超出缓冲区范围 + return -2; + + while (*cur < msgend) + { + len = __dns_parser_uint8(*cur); + + if ((len & 0xC0) == 0) // 普通标签（长度小于 63） + { + (*cur)++; + if (len == 0) + break; // 解析结束 + if (len > DNS_LABELS_MAX || *cur + len > msgend || hcur + len + 1 > DNS_NAMES_MAX) + return -2; // 长度超限或缓冲区溢出 + + memcpy(phost + hcur, *cur, len); // 拷贝标签内容 + *cur += len; + hcur += len; + phost[hcur++] = '.'; // 添加分隔符 + } + else if ((len & 0xC0) == 0xC0) // 消息压缩（指针） + { + pointer = __dns_parser_uint16(*cur) & 0x3FFF; // 提取指针地址 + if (pointer >= parser->msgsize || (const char *)parser->msgbase + pointer >= *cur) + return -2; // 指针超限或指向无效位置 + + *cur += 2; + + if (curbackup == NULL) // 第一次遇到指针时备份当前解析位置 + curbackup = *cur; + *cur = (const char *)parser->msgbase + pointer; + } + else + return -2; // 非法标识 + } + + if (curbackup != NULL) + *cur = curbackup; // 恢复解析位置 + + if (hcur > 1 && phost[hcur - 1] == '.') + hcur--; // 移除末尾多余的点 + + if (hcur == 0) + phost[hcur++] = '.'; // 根域名情况 + phost[hcur++] = '\0'; // 添加字符串结束符 + + return 0; +} + +// === 记录释放函数 === + +/** + * @brief 释放单个 DNS 记录的内存。 + * @param r 待释放的记录。 + */ +static void __dns_parser_free_record(struct __dns_record_entry *r) +{ + switch (r->record.type) + { + case DNS_TYPE_SOA: // SOA 记录需要释放 mname 和 rname + { + struct dns_record_soa *soa = (struct dns_record_soa *)(r->record.rdata); + free(soa->mname); + free(soa->rname); + break; + } + case DNS_TYPE_SRV: // SRV 记录需要释放 target + { + struct dns_record_srv *srv = (struct dns_record_srv *)(r->record.rdata); + free(srv->target); + break; + } + case DNS_TYPE_MX: // MX 记录需要释放 exchange + { + struct dns_record_mx *mx = (struct dns_record_mx *)(r->record.rdata); + free(mx->exchange); + break; + } + } + free(r->record.name); // 释放记录名称 + free(r); // 释放记录本身 +} + +/** + * @brief 释放 DNS 记录链表中的所有记录。 + * @param head 链表头节点。 + */ +static void __dns_parser_free_record_list(struct list_head *head) +{ + struct list_head *pos, *tmp; + struct __dns_record_entry *entry; + + list_for_each_safe(pos, tmp, head) + { + entry = list_entry(pos, struct __dns_record_entry, entry_list); + list_del(pos); // 从链表中移除节点 + __dns_parser_free_record(entry); + } +} + +// 更多函数的注释省略，但每个函数逻辑相似，按需补充！