前言

Flow Classify示例应用程序基于转发应用程序的简单框架示例。 它旨在演示使用Flow Classify库API的DPDK转发应用程序的基本组件

flow_classify例子对于DPDK的学习具有很重要的意义，是比较重要的章节。有点类似于linux网络中的iptables功能，也有点类似于我们在linux内核中开发的防火墙功能。我们可以使用flow模块对数据包进行统计，丢弃等基本的操作。

程序代码

ACL介绍

首先该例程中主要是面向的对象是IP流量中的五元组信息。即源ip地址，目的ip地址，源端口号，目的端口号，协议号。学过linux网络的都知道，该五元组可以决定一个数据包的唯一性。因为我们操作的是IP流量五元组，所以这里使用的ACL classify算法。ACL规则主要面向的是IP流量中的五元组信息。

关于classify算法可以参考DPDK ACL算法介绍

DPDK报文分类与访问控制

dpdk提供了一个访问控制库，提供了基于一系列分类规则对接收到的报文进行分类的能力。

ACL库用来在一系列规则上执行N元组查找，可以实现多个分类和对每个分类查找最佳匹配（最高优先级)。

ACL库的api提供如下基本操作：

创建一个新的访问控制（AC）环境实例（context）添加规则到这个环境实例为这个实例里所有的规则，创建必需的运行时结构体来指针报文分类执行接收报文分类删除AC环境实例和对应的运行时结构体，并释放内存

该例程是对官方例程flow_classify补充说明flow_classify链接地址

程序

/* SPDX-License-Identifier: BSD-3-Clause * Copyright(c) 2017 Intel Corporation */ #include <stdint.h> #include <inttypes.h> #include <getopt.h> #include <rte_eal.h> #include <rte_ethdev.h> #include <rte_cycles.h> #include <rte_lcore.h> #include <rte_mbuf.h> #include <rte_flow.h> #include <rte_flow_classify.h> #include <rte_table_acl.h> #define RX_RING_SIZE 1024 #define TX_RING_SIZE 1024 #define NUM_MBUFS 8191 #define MBUF_CACHE_SIZE 250 #define BURST_SIZE 32 #define MAX_NUM_CLASSIFY 30 #define FLOW_CLASSIFY_MAX_RULE_NUM 91 #define FLOW_CLASSIFY_MAX_PRIORITY 8 #define FLOW_CLASSIFIER_NAME_SIZE 64 #define COMMENT_LEAD_CHAR ('#') #define OPTION_RULE_IPV4 "rule_ipv4" #define RTE_LOGTYPE_FLOW_CLASSIFY RTE_LOGTYPE_USER3 #define flow_classify_log(format, ...) \ RTE_LOG(ERR, FLOW_CLASSIFY, format, ##__VA_ARGS__) #define uint32_t_to_char(ip, a, b, c, d) do {\ *a = (unsigned char)(ip >> 24 & 0xff);\ *b = (unsigned char)(ip >> 16 & 0xff);\ *c = (unsigned char)(ip >> 8 & 0xff);\ *d = (unsigned char)(ip & 0xff);\ } while (0) enum { CB_FLD_SRC_ADDR, CB_FLD_DST_ADDR, CB_FLD_SRC_PORT, CB_FLD_SRC_PORT_DLM, CB_FLD_SRC_PORT_MASK, CB_FLD_DST_PORT, CB_FLD_DST_PORT_DLM, CB_FLD_DST_PORT_MASK, CB_FLD_PROTO, CB_FLD_PRIORITY, CB_FLD_NUM, }; static struct{ const char *rule_ipv4_name; } parm_config; const char cb_port_delim[] = ":"; static const struct rte_eth_conf port_conf_default = { .rxmode = { .max_rx_pkt_len = ETHER_MAX_LEN, }, }; struct flow_classifier { struct rte_flow_classifier *cls; }; struct flow_classifier_acl { struct flow_classifier cls; } __rte_cache_aligned; /* ACL field definitions for IPv4 5 tuple rule */ enum { PROTO_FIELD_IPV4, SRC_FIELD_IPV4, DST_FIELD_IPV4, SRCP_FIELD_IPV4, DSTP_FIELD_IPV4, NUM_FIELDS_IPV4 }; enum { PROTO_INPUT_IPV4, SRC_INPUT_IPV4, DST_INPUT_IPV4, SRCP_DESTP_INPUT_IPV4 }; static struct rte_acl_field_def ipv4_defs[NUM_FIELDS_IPV4] = { /* first input field - always one byte long. */ { .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint8_t), .field_index = PROTO_FIELD_IPV4, .input_index = PROTO_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, next_proto_id), }, /* next input field (IPv4 source address) - 4 consecutive bytes. */ { /* rte_flow uses a bit mask for IPv4 addresses */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint32_t), .field_index = SRC_FIELD_IPV4, .input_index = SRC_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, src_addr), }, /* next input field (IPv4 destination address) - 4 consecutive bytes. */ { /* rte_flow uses a bit mask for IPv4 addresses */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint32_t), .field_index = DST_FIELD_IPV4, .input_index = DST_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + offsetof(struct ipv4_hdr, dst_addr), }, /* * Next 2 fields (src & dst ports) form 4 consecutive bytes. * * They share the same input index. */ { /* rte_flow uses a bit mask for protocol ports */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint16_t), .field_index = SRCP_FIELD_IPV4, .input_index = SRCP_DESTP_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + offsetof(struct tcp_hdr, src_port), }, { /* rte_flow uses a bit mask for protocol ports */ .type = RTE_ACL_FIELD_TYPE_BITMASK, .size = sizeof(uint16_t), .field_index = DSTP_FIELD_IPV4, .input_index = SRCP_DESTP_INPUT_IPV4, .offset = sizeof(struct ether_hdr) + sizeof(struct ipv4_hdr) + offsetof(struct tcp_hdr, dst_port), }, }; /* flow classify data */ static int num_classify_rules; static struct rte_flow_classify_rule *rules[MAX_NUM_CLASSIFY]; static struct rte_flow_classify_ipv4_5tuple_stats ntuple_stats; static struct rte_flow_classify_stats classify_stats = { .stats = (void **)&ntuple_stats }; /* parameters for rte_flow_classify_validate and * rte_flow_classify_table_entry_add functions */ static struct rte_flow_item eth_item = { RTE_FLOW_ITEM_TYPE_ETH, 0, 0, 0 }; static struct rte_flow_item end_item = { RTE_FLOW_ITEM_TYPE_END, 0, 0, 0 }; /* sample actions: * "actions count / end" */ struct rte_flow_query_count count = { .reset = 1, .hits_set = 1, .bytes_set = 1, .hits = 0, .bytes = 0, }; // 启用流量计数器 static struct rte_flow_action count_action = { RTE_FLOW_ACTION_TYPE_COUNT, &count}; static struct rte_flow_action end_action = { RTE_FLOW_ACTION_TYPE_END, 0}; // rte_flow_action 结构体数组(terminated by the END pattern item)，表示流规则的动作，比如QUEUE, DROP, END等等 // 这里的action有两个动作，分别是计数和结束 static struct rte_flow_action actions[2]; /* sample attributes */ static struct rte_flow_attr attr; // 代表的一条流规则属性 /* flow_classify.c: * Based on DPDK skeleton forwarding example. */ /* * Initializes a given port using global settings and with the RX buffers * coming from the mbuf_pool passed as a parameter. */ static inline int port_init(uint8_t port, struct rte_mempool *mbuf_pool) { struct rte_eth_conf port_conf = port_conf_default; struct ether_addr addr; const uint16_t rx_rings = 1, tx_rings = 1; int retval; uint16_t q; struct rte_eth_dev_info dev_info; struct rte_eth_txconf txconf; if (!rte_eth_dev_is_valid_port(port)) return -1; // 设置port的属性 rte_eth_dev_info_get(port, &dev_info); if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE) port_conf.txmode.offloads |= DEV_TX_OFFLOAD_MBUF_FAST_FREE; /* Configure the Ethernet device. */ // 设置网卡接收和发送队列的个数以及属性 retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf); if (retval != 0) return retval; /* Allocate and set up 1 RX queue per Ethernet port. */ for (q = 0; q < rx_rings; q++) { // 分配一个接收队列 retval = rte_eth_rx_queue_setup(port, q, RX_RING_SIZE, rte_eth_dev_socket_id(port), NULL, mbuf_pool); if (retval < 0) return retval; } txconf = dev_info.default_txconf; txconf.offloads = port_conf.txmode.offloads; /* Allocate and set up 1 TX queue per Ethernet port. */ for (q = 0; q < tx_rings; q++) { // 分配和设置一个发送队列 retval = rte_eth_tx_queue_setup(port, q, TX_RING_SIZE, rte_eth_dev_socket_id(port), &txconf); if (retval < 0) return retval; } /* Start the Ethernet port. */ // 开启网卡转发 retval = rte_eth_dev_start(port); if (retval < 0) return retval; /* Display the port MAC address. */ rte_eth_macaddr_get(port, &addr); printf("Port %u MAC: %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 " %02" PRIx8 "\n", port, addr.addr_bytes[0], addr.addr_bytes[1], addr.addr_bytes[2], addr.addr_bytes[3], addr.addr_bytes[4], addr.addr_bytes[5]); /* Enable RX in promiscuous mode for the Ethernet device. */ // 开始网卡的混杂模式 rte_eth_promiscuous_enable(port); return 0; } /* * The lcore main. This is the main thread that does the work, reading from * an input port classifying the packets and writing to an output port. */ static __attribute__((noreturn)) void lcore_main(struct flow_classifier *cls_app) { uint16_t port; int ret; int i = 0; /* 从flow_classifier表中删除流分类规则 cls_app->cls: 流分类器句柄 rules[7]: 流分类规则 */ ret = rte_flow_classify_table_entry_delete(cls_app->cls, rules[7]); if (ret) printf("table_entry_delete failed [7] %d\n\n", ret); else printf("table_entry_delete succeeded [7]\n\n"); /* * Check that the port is on the same NUMA node as the polling thread * for best performance. */ RTE_ETH_FOREACH_DEV(port) if (rte_eth_dev_socket_id(port) > 0 && rte_eth_dev_socket_id(port) != (int)rte_socket_id()) { printf("\n\n"); printf("WARNING: port %u is on remote NUMA node\n", port); printf("to polling thread.\n"); printf("Performance will not be optimal.\n"); } printf("\nCore %u forwarding packets. ", rte_lcore_id()); printf("[Ctrl+C to quit]\n"); /* Run until the application is quit or killed. */ for (;;) { /* * Receive packets on a port, classify them and forward them * on the paired port. * The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc. */ RTE_ETH_FOREACH_DEV(port) { /* Get burst of RX packets, from first port of pair. */ struct rte_mbuf *bufs[BURST_SIZE]; // 接收数据报文 const uint16_t nb_rx = rte_eth_rx_burst(port, 0, bufs, BURST_SIZE); if (unlikely(nb_rx == 0)) continue; // 遍历rules for (i = 0; i < MAX_NUM_CLASSIFY; i++) { if (rules[i]) { /* 查看burst中是否有任何数据包与表中的一条流规则匹配 cls_app->cls: 流分类器句柄 bufs： 指向数据报文 nb_rx： 数据报文个数 rules： 流分类器规则 classify_stats： 流分类器统计 */ ret = rte_flow_classifier_query( cls_app->cls, bufs, nb_rx, rules[i], &classify_stats); if (ret) printf( "rule [%d] query failed ret [%d]\n\n", i, ret); else { printf( "rule[%d] count=%"PRIu64"\n", i, ntuple_stats.counter1); printf("proto = %d\n", ntuple_stats.ipv4_5tuple.proto); } } } /* Send burst of TX packets, to second port of pair. */ const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0, bufs, nb_rx); /* Free any unsent packets. */ if (unlikely(nb_tx < nb_rx)) { uint16_t buf; for (buf = nb_tx; buf < nb_rx; buf++) rte_pktmbuf_free(bufs[buf]); } } } } /* * Parse IPv4 5 tuple rules file, ipv4_rules_file.txt. * Expected format: * <src_ipv4_addr>'/'<masklen> <space> \ * <dst_ipv4_addr>'/'<masklen> <space> \ * <src_port> <space> ":" <src_port_mask> <space> \ * <dst_port> <space> ":" <dst_port_mask> <space> \ * <proto>'/'<proto_mask> <space> \ * <priority> */ static int get_cb_field(char **in, uint32_t *fd, int base, unsigned long lim, char dlm) { unsigned long val; char *end; errno = 0; val = strtoul(*in, &end, base); if (errno != 0 || end[0] != dlm || val > lim) return -EINVAL; *fd = (uint32_t)val; *in = end + 1; return 0; } static int parse_ipv4_net(char *in, uint32_t *addr, uint32_t *mask_len) { uint32_t a, b, c, d, m; if (get_cb_field(&in, &a, 0, UINT8_MAX, '.')) return -EINVAL; if (get_cb_field(&in, &b, 0, UINT8_MAX, '.')) return -EINVAL; if (get_cb_field(&in, &c, 0, UINT8_MAX, '.')) return -EINVAL; if (get_cb_field(&in, &d, 0, UINT8_MAX, '/')) return -EINVAL; if (get_cb_field(&in, &m, 0, sizeof(uint32_t) * CHAR_BIT, 0)) return -EINVAL; addr[0] = IPv4(a, b, c, d); mask_len[0] = m; return 0; } static int parse_ipv4_5tuple_rule(char *str, struct rte_eth_ntuple_filter *ntuple_filter) { int i, ret; char *s, *sp, *in[CB_FLD_NUM]; static const char *dlm = " \t\n"; int dim = CB_FLD_NUM; uint32_t temp; // 解析传入的字符串，将结果存入in数组中 s = str; for (i = 0; i != dim; i++, s = NULL) { in[i] = strtok_r(s, dlm, &sp); if (in[i] == NULL) return -EINVAL; printf("============ %s\n", in[i]); } // 解析源ip地址和子网掩码 ret = parse_ipv4_net(in[CB_FLD_SRC_ADDR], &ntuple_filter->src_ip, &ntuple_filter->src_ip_mask); if (ret != 0) { flow_classify_log("failed to read source address/mask: %s\n", in[CB_FLD_SRC_ADDR]); return ret; } // 解析目的ip地址和子网掩码 ret = parse_ipv4_net(in[CB_FLD_DST_ADDR], &ntuple_filter->dst_ip, &ntuple_filter->dst_ip_mask); if (ret != 0) { flow_classify_log("failed to read source address/mask: %s\n", in[CB_FLD_DST_ADDR]); return ret; } // 获取源端口号 if (get_cb_field(&in[CB_FLD_SRC_PORT], &temp, 0, UINT16_MAX, 0)) return -EINVAL; ntuple_filter->src_port = (uint16_t)temp; if (strncmp(in[CB_FLD_SRC_PORT_DLM], cb_port_delim, sizeof(cb_port_delim)) != 0) return -EINVAL; // 获取源端口掩码 if (get_cb_field(&in[CB_FLD_SRC_PORT_MASK], &temp, 0, UINT16_MAX, 0)) return -EINVAL; ntuple_filter->src_port_mask = (uint16_t)temp; // 获取目的端口号 if (get_cb_field(&in[CB_FLD_DST_PORT], &temp, 0, UINT16_MAX, 0)) return -EINVAL; ntuple_filter->dst_port = (uint16_t)temp; if (strncmp(in[CB_FLD_DST_PORT_DLM], cb_port_delim, sizeof(cb_port_delim)) != 0) return -EINVAL; // 获取目的端口掩码 if (get_cb_field(&in[CB_FLD_DST_PORT_MASK], &temp, 0, UINT16_MAX, 0)) return -EINVAL; ntuple_filter->dst_port_mask = (uint16_t)temp; // 获取l4协议号 if (get_cb_field(&in[CB_FLD_PROTO], &temp, 0, UINT8_MAX, '/')) return -EINVAL; ntuple_filter->proto = (uint8_t)temp; // 获取协议号掩码 if (get_cb_field(&in[CB_FLD_PROTO], &temp, 0, UINT8_MAX, 0)) return -EINVAL; ntuple_filter->proto_mask = (uint8_t)temp; // 获取优先级 if (get_cb_field(&in[CB_FLD_PRIORITY], &temp, 0, UINT16_MAX, 0)) return -EINVAL; ntuple_filter->priority = (uint16_t)temp; if (ntuple_filter->priority > FLOW_CLASSIFY_MAX_PRIORITY) ret = -EINVAL; return ret; } /* Bypass comment and empty lines */ static inline int is_bypass_line(char *buff) { int i = 0; /* comment line */ if (buff[0] == COMMENT_LEAD_CHAR) return 1; /* empty line */ while (buff[i] != '\0') { if (!isspace(buff[i])) return 0; i++; } return 1; } static uint32_t convert_depth_to_bitmask(uint32_t depth_val) { uint32_t bitmask = 0; int i, j; for (i = depth_val, j = 0; i > 0; i--, j++) bitmask |= (1 << (31 - j)); return bitmask; } static int add_classify_rule(struct rte_eth_ntuple_filter *ntuple_filter, struct flow_classifier *cls_app) { int ret = -1; int key_found; /* rte_flow_item： ACL 规则的详细内容。 会从最低协议层开始堆叠flow_item来形成一个匹配模式。必须由 end_item 结尾。 */ struct rte_flow_error error; struct rte_flow_item_ipv4 ipv4_spec; struct rte_flow_item_ipv4 ipv4_mask; struct rte_flow_item ipv4_udp_item; struct rte_flow_item ipv4_tcp_item; struct rte_flow_item ipv4_sctp_item; struct rte_flow_item_udp udp_spec; struct rte_flow_item_udp udp_mask; struct rte_flow_item udp_item; struct rte_flow_item_tcp tcp_spec; struct rte_flow_item_tcp tcp_mask; struct rte_flow_item tcp_item; struct rte_flow_item_sctp sctp_spec; struct rte_flow_item_sctp sctp_mask; struct rte_flow_item sctp_item; struct rte_flow_item pattern_ipv4_5tuple[4]; struct rte_flow_classify_rule *rule; uint8_t ipv4_proto; if (num_classify_rules >= MAX_NUM_CLASSIFY) { printf( "\nINFO: classify rule capacity %d reached\n", num_classify_rules); return ret; } /* set up parameters for validate and add */ memset(&ipv4_spec, 0, sizeof(ipv4_spec)); // 填充ip头部协议字段(上层协议) ipv4_spec.hdr.next_proto_id = ntuple_filter->proto; // 填充ip头部源ip地址 ipv4_spec.hdr.src_addr = ntuple_filter->src_ip; // 填充ip头部目的ip地址 ipv4_spec.hdr.dst_addr = ntuple_filter->dst_ip; ipv4_proto = ipv4_spec.hdr.next_proto_id; // TODO:ipv4_mask的作用是什么？ memset(&ipv4_mask, 0, sizeof(ipv4_mask)); ipv4_mask.hdr.next_proto_id = ntuple_filter->proto_mask; ipv4_mask.hdr.src_addr = ntuple_filter->src_ip_mask; // 转化为掩码 ipv4_mask.hdr.src_addr = convert_depth_to_bitmask(ipv4_mask.hdr.src_addr); ipv4_mask.hdr.dst_addr = ntuple_filter->dst_ip_mask; ipv4_mask.hdr.dst_addr = convert_depth_to_bitmask(ipv4_mask.hdr.dst_addr); // 根据ip头部中的协议字段来进行分类处理 switch (ipv4_proto) { case IPPROTO_UDP: // 如果是UDP // 匹配IPV4 ipv4_udp_item.type = RTE_FLOW_ITEM_TYPE_IPV4; ipv4_udp_item.spec = &ipv4_spec; ipv4_udp_item.mask = &ipv4_mask; ipv4_udp_item.last = NULL; // 填充UDP头部 // 填充UDP字段源端口号 udp_spec.hdr.src_port = ntuple_filter->src_port; // 填充UDP字段目的端口号 udp_spec.hdr.dst_port = ntuple_filter->dst_port; // 填充UDP字段数据长度 udp_spec.hdr.dgram_len = 0; // 填充UDP字段数据校验和 udp_spec.hdr.dgram_cksum = 0; // 填充udp的掩码 udp_mask.hdr.src_port = ntuple_filter->src_port_mask; udp_mask.hdr.dst_port = ntuple_filter->dst_port_mask; udp_mask.hdr.dgram_len = 0; udp_mask.hdr.dgram_cksum = 0; // 匹配UDP udp_item.type = RTE_FLOW_ITEM_TYPE_UDP; udp_item.spec = &udp_spec; udp_item.mask = &udp_mask; udp_item.last = NULL; // 设置组内规则优先级属性 attr.priority = ntuple_filter->priority; // 将每个规则添加到规则数组中 pattern_ipv4_5tuple[1] = ipv4_udp_item; pattern_ipv4_5tuple[2] = udp_item; break; case IPPROTO_TCP: // 如果是TCP // 匹配IPV4 ipv4_tcp_item.type = RTE_FLOW_ITEM_TYPE_IPV4; ipv4_tcp_item.spec = &ipv4_spec; ipv4_tcp_item.mask = &ipv4_mask; ipv4_tcp_item.last = NULL; // 填充TCP头部信息 memset(&tcp_spec, 0, sizeof(tcp_spec)); // 填充TCP头部字段源端口号 tcp_spec.hdr.src_port = ntuple_filter->src_port; // 填充TCP头部字段目的端口号 tcp_spec.hdr.dst_port = ntuple_filter->dst_port; // 填充TCP掩码 memset(&tcp_mask, 0, sizeof(tcp_mask)); tcp_mask.hdr.src_port = ntuple_filter->src_port_mask; tcp_mask.hdr.dst_port = ntuple_filter->dst_port_mask; // 匹配TCP tcp_item.type = RTE_FLOW_ITEM_TYPE_TCP; tcp_item.spec = &tcp_spec; tcp_item.mask = &tcp_mask; tcp_item.last = NULL; // 设置组内规则优先级 attr.priority = ntuple_filter->priority; // 将每个规则添加到规则数组中 pattern_ipv4_5tuple[1] = ipv4_tcp_item; pattern_ipv4_5tuple[2] = tcp_item; break; case IPPROTO_SCTP: // 如果是SCTP // 匹配IPV4 ipv4_sctp_item.type = RTE_FLOW_ITEM_TYPE_IPV4; ipv4_sctp_item.spec = &ipv4_spec; ipv4_sctp_item.mask = &ipv4_mask; ipv4_sctp_item.last = NULL; // 填充SCTP头部字段 sctp_spec.hdr.src_port = ntuple_filter->src_port; sctp_spec.hdr.dst_port = ntuple_filter->dst_port; sctp_spec.hdr.cksum = 0; sctp_spec.hdr.tag = 0; sctp_mask.hdr.src_port = ntuple_filter->src_port_mask; sctp_mask.hdr.dst_port = ntuple_filter->dst_port_mask; sctp_mask.hdr.cksum = 0; sctp_mask.hdr.tag = 0; // 匹配SCTP sctp_item.type = RTE_FLOW_ITEM_TYPE_SCTP; sctp_item.spec = &sctp_spec; sctp_item.mask = &sctp_mask; sctp_item.last = NULL; // 将每个规则添加到规则数组中 attr.priority = ntuple_filter->priority; pattern_ipv4_5tuple[1] = ipv4_sctp_item; pattern_ipv4_5tuple[2] = sctp_item; break; default: return ret; } // 规则适用于入口流量 attr.ingress = 1; // 匹配二层数据报文 pattern_ipv4_5tuple[0] = eth_item; // 结束匹配 pattern_ipv4_5tuple[3] = end_item; // 指定action actions[0] = count_action; actions[1] = end_action; /* Validate and add rule */ /* 流分类验证 cls_app->cls: 流分类器实例 attr： 流规则属性 pattern_ipv4_5tuple: 模式指定（列表由END模式项终止） actions： 关联动作（列表由END模式项终止） error： 如果不为NULL，则执行详细的错误报告。仅在发生错误的情况下初始化结构 */ ret = rte_flow_classify_validate(cls_app->cls, &attr, pattern_ipv4_5tuple, actions, &error); if (ret) { printf("table entry validate failed ipv4_proto = %u\n", ipv4_proto); return ret; } /* 将流分类规则添加到flow_classifier表中 cls_app->cls: 流分类器实例 attr： 流规则属性 pattern_ipv4_5tuple: 模式指定（列表由END模式项终止） actions： 关联动作（列表由END模式项终止） key_found: 如果规则已经存在，则返回1，否则返回0 error： 如果不为NULL，则执行详细的错误报告。仅在发生错误的情况下初始化结构 成功时返回有效句柄rule */ rule = rte_flow_classify_table_entry_add( cls_app->cls, &attr, pattern_ipv4_5tuple, actions, &key_found, &error); if (rule == NULL) { printf("table entry add failed ipv4_proto = %u\n", ipv4_proto); ret = -1; return ret; } // 将句柄存放在rules数组中 rules[num_classify_rules] = rule; num_classify_rules++; return 0; } static int add_rules(const char *rule_path, struct flow_classifier *cls_app) { FILE *fh; char buff[LINE_MAX]; unsigned int i = 0; unsigned int total_num = 0; //用于定义ntuple过滤器条目的结构 struct rte_eth_ntuple_filter ntuple_filter; int ret; // 打开指定的文件 fh = fopen(rule_path, "rb"); if (fh == NULL) rte_exit(EXIT_FAILURE, "%s: fopen %s failed\n", __func__, rule_path); // 移动到文件头部 ret = fseek(fh, 0, SEEK_SET); if (ret) rte_exit(EXIT_FAILURE, "%s: fseek %d failed\n", __func__, ret); i = 0; // 循环读取指定的文件的每一行 while (fgets(buff, LINE_MAX, fh) != NULL) { // 跳过注释和空行 if (is_bypass_line(buff)) continue; if (total_num >= FLOW_CLASSIFY_MAX_RULE_NUM - 1) { printf("\nINFO: classify rule capacity %d reached\n", total_num); break; } // 解析5元组，存放在ntuple_filter中 if (parse_ipv4_5tuple_rule(buff, &ntuple_filter) != 0) rte_exit(EXIT_FAILURE, "%s Line %u: parse rules error\n", rule_path, i); // 将5元组加入分类规则中 if (add_classify_rule(&ntuple_filter, cls_app) != 0) rte_exit(EXIT_FAILURE, "add rule error\n"); total_num++; } fclose(fh); return 0; } /* display usage */ static void print_usage(const char *prgname) { printf("%s usage:\n", prgname); printf("[EAL options] -- --"OPTION_RULE_IPV4"=FILE: "); printf("specify the ipv4 rules file.\n"); printf("Each rule occupies one line in the file.\n"); } /* Parse the argument given in the command line of the application */ static int parse_args(int argc, char **argv) { int opt, ret; char **argvopt; int option_index; char *prgname = argv[0]; static struct option lgopts[] = { {OPTION_RULE_IPV4, 1, 0, 0}, {NULL, 0, 0, 0} }; argvopt = argv; while ((opt = getopt_long(argc, argvopt, "", lgopts, &option_index)) != EOF) { switch (opt) { /* long options */ case 0: if (!strncmp(lgopts[option_index].name, OPTION_RULE_IPV4, sizeof(OPTION_RULE_IPV4))) parm_config.rule_ipv4_name = optarg; break; default: print_usage(prgname); return -1; } } if (optind >= 0) argv[optind-1] = prgname; ret = optind-1; optind = 1; /* reset getopt lib */ return ret; } /* * The main function, which does initialization and calls the lcore_main * function. */ int main(int argc, char *argv[]) { struct rte_mempool *mbuf_pool; uint16_t nb_ports; uint16_t portid; int ret; int socket_id; // ACL(访问控制列表)参数 struct rte_table_acl_params table_acl_params; // 创建ACL table表参数 struct rte_flow_classify_table_params cls_table_params; struct flow_classifier *cls_app; // 流分类器创建参数 struct rte_flow_classifier_params cls_params; uint32_t size; /* Initialize the Environment Abstraction Layer (EAL). */ // 初始化eal层 ret = rte_eal_init(argc, argv); if (ret < 0) rte_exit(EXIT_FAILURE, "Error with EAL initialization\n"); argc -= ret; argv += ret; /* parse application arguments (after the EAL ones) */ //解析参数 ret = parse_args(argc, argv); if (ret < 0) rte_exit(EXIT_FAILURE, "Invalid flow_classify parameters\n"); /* Check that there is an even number of ports to send/receive on. */ // 获取有效网卡的个数 nb_ports = rte_eth_dev_count_avail(); if (nb_ports < 2 || (nb_ports & 1)) rte_exit(EXIT_FAILURE, "Error: number of ports must be even\n"); /* Creates a new mempool in memory to hold the mbufs. */ /* 创建mbuf_pool */ mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", NUM_MBUFS * nb_ports, MBUF_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE, rte_socket_id()); if (mbuf_pool == NULL) rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n"); /* Initialize all ports. */ RTE_ETH_FOREACH_DEV(portid) if (port_init(portid, mbuf_pool) != 0) rte_exit(EXIT_FAILURE, "Cannot init port %"PRIu8 "\n", portid); // 只在一个核心上运行 if (rte_lcore_count() > 1) printf("\nWARNING: Too many lcores enabled. Only 1 used.\n"); socket_id = rte_eth_dev_socket_id(0); /* Memory allocation */ // 分配一个struct flow_classifier_acl大小的缓存 size = RTE_CACHE_LINE_ROUNDUP(sizeof(struct flow_classifier_acl)); // malloc后必须调用free,TODO: 和C语言中的malloc类似 cls_app = rte_zmalloc(NULL, size, RTE_CACHE_LINE_SIZE); if (cls_app == NULL) rte_exit(EXIT_FAILURE, "Cannot allocate classifier memory\n"); // 流分类器参数的name cls_params.name = "flow_classifier"; // 流分类器参数的socket_id cls_params.socket_id = socket_id; // 创建流分类器，创建成功返回流分类器实例，创建失败返回NULL cls_app->cls = rte_flow_classifier_create(&cls_params); if (cls_app->cls == NULL) { rte_free(cls_app); rte_exit(EXIT_FAILURE, "Cannot create classifier\n"); } /* initialise ACL table params */ // 设置ACL的name字段 table_acl_params.name = "table_acl_ipv4_5tuple"; // ACL表中的最大规则数，这里的91条 table_acl_params.n_rules = FLOW_CLASSIFY_MAX_RULE_NUM; // ACL表中的字段数 table_acl_params.n_rule_fields = RTE_DIM(ipv4_defs); // 拷贝ACL表中的规则 memcpy(table_acl_params.field_format, ipv4_defs, sizeof(ipv4_defs)); /* initialise table create params */ // ACL表操作ops cls_table_params.ops = &rte_table_acl_ops; // 传递给创建ACL函数的参数，这里是ACL创建的时候传递的结构体 cls_table_params.arg_create = &table_acl_params; // 分类表类型 cls_table_params.type = RTE_FLOW_CLASSIFY_TABLE_ACL_IP4_5TUPLE; /* 流量分类表的创建 cls_app->cls: 处理流分类器实例指针 cls_table_params： 用于流量分类表参数 */ ret = rte_flow_classify_table_create(cls_app->cls, &cls_table_params); if (ret) { rte_flow_classifier_free(cls_app->cls); rte_free(cls_app); rte_exit(EXIT_FAILURE, "Failed to create classifier table\n"); } /* read file of IPv4 5 tuple rules and initialize parameters * for rte_flow_classify_validate and rte_flow_classify_table_entry_add * API's. */ /* 读取IPV4的5元组文件，作为rte_flow_classify_validate和rte_flow_classify_table_entry_add的初始化参数 parm_config.rule_ipv4_name: 在本程序中主要是--rule_ipv4="../ipv4_rules_file.txt"后面跟的参数ipv4_rules_file.txt cls_app: 自定义数据结构 */ if (add_rules(parm_config.rule_ipv4_name, cls_app)) { rte_flow_classifier_free(cls_app->cls); rte_free(cls_app); rte_exit(EXIT_FAILURE, "Failed to add rules\n"); } /* Call lcore_main on the master core only. */ lcore_main(cls_app); return 0; }

代码的相关流程和说明请看代码中的注释。

这里简单描述一下该例程实现的功能

首先我们需要至少绑定2的倍数的网卡创建flow分类器然后会读取例程中ipv4_rules_file.txt文件(文件中主要是5元组)。将规则绑定到flow分类器中配置flow分类器中规则的action(该例程中主要是统计的action)配置网卡的属性(配置发送和接收队列)将接收到的数据交给flow分类器。如果匹配则统计数据

这里给出几个网上的参考链接，flow模块比较困难，需要好好的研究。DPDK flow_classify 源码阅读 本篇文章大量参考了上文链接中的文章相关内容。但是为什么还需要写出来呢？因为链接中的文章只是对于程序作了大致的介绍。由于flow模块非常重要，所以我补充了相关知识梳理的流程图(该流程图主要是描述了分类器的创建和添加规则的流程，以及分类器的组成，个人认为这一部分才是核心):

关于运行的结果我会在后面添加。