diff options
Diffstat (limited to 'lib/libtle_glue/icmp.c')
| -rw-r--r-- | lib/libtle_glue/icmp.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/lib/libtle_glue/icmp.c b/lib/libtle_glue/icmp.c new file mode 100644 index 0000000..aba1c4b --- /dev/null +++ b/lib/libtle_glue/icmp.c @@ -0,0 +1,297 @@ +/* + * Copyright (c) 2018 Ant Financial Services Group. + * 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 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <time.h> +#include <netinet/icmp6.h> + +#include <rte_common.h> +#include <rte_byteorder.h> +#include <rte_ethdev.h> +#include <rte_icmp.h> +#include <rte_ip.h> + +#include "log.h" +#include "ctx.h" +#include "internal.h" + +#define ICMP_ECHOREPLY 0 /* Echo Reply */ +#define ICMP_ECHO 8 /* Echo Request */ +#define ICMP_TIMESTAMP 13 /* Timestamp Request */ +#define ICMP_TIMESTAMPREPLY 14 /* Timestamp Reply */ + +/* Codes for TIME_EXCEEDED. */ +#define ICMP_EXC_TTL 0 /* TTL count exceeded */ +#define ICMP_EXC_FRAGTIME 1 /* Fragment Reass time exceeded */ + +/* Parameters used to convert the timespec values */ +#define SECONDS_PER_DAY 86400L +#define MSEC_PER_SEC 1000L +#define USEC_PER_MSEC 1000L +#define NSEC_PER_USEC 1000L +#define NSEC_PER_MSEC (NSEC_PER_USEC * USEC_PER_MSEC) + +#define IS_IPV4_BCAST(x) ((x) == (uint32_t)0xFFFFFFFF) + +struct icmp_pkt { + struct icmp_hdr icmp_h; + uint32_t times[3]; +}; + +/* Return remainder for ``dividend / divisor`` */ +static inline uint32_t +div_uint64_rem(uint64_t dividend, uint32_t divisor) +{ + return dividend % divisor; +} + +/* Return milliseconds since midnight (UTC) in network byte order. */ +static uint32_t +current_timestamp(void) +{ + struct timespec ts; + uint32_t msecs; + uint32_t secs; + + (void)clock_gettime(CLOCK_REALTIME, &ts); + + /* Get secs since midnight. */ + secs = div_uint64_rem(ts.tv_sec, SECONDS_PER_DAY); + /* Convert to msecs. */ + msecs = secs * MSEC_PER_SEC; + /* Convert nsec to msec. */ + msecs += (uint32_t)ts.tv_nsec / NSEC_PER_MSEC; + + /* Convert to network byte order. */ + return rte_cpu_to_be_32(msecs); +} + +/* + * Process the checksum of an ICMP packet. The checksum field must be set + * to 0 by the caller. + */ +static uint16_t +icmp_cksum(const struct icmp_hdr *icmp, uint32_t data_len) +{ + uint16_t cksum; + + cksum = rte_raw_cksum(icmp, sizeof(struct icmp_hdr) + data_len); + return (cksum == 0xffff) ? cksum : ~cksum; +} + +/** + * Receive and handle an ICMP packet. + * + * @param ctx + * The pointer to the glue context. + * @param pkt + * The pointer to the raw packet data. + * @param l2_len + * The the size of the l2 header. + * @return + * MUST return NULL now. :-) + */ +struct rte_mbuf * +icmp_recv(struct glue_ctx *ctx, struct rte_mbuf *pkt, + uint32_t l2_len, uint32_t l3_len) +{ + struct ether_addr eth_addr; + struct icmp_pkt *icmp_pkt; + struct ether_hdr *eth_h; + struct icmp_hdr *icmp_h; + struct ipv4_hdr *ip_h; + uint32_t ip_addr; + uint32_t cksum; + + eth_h = rte_pktmbuf_mtod(pkt, struct ether_hdr *); + ip_h = (struct ipv4_hdr *) ((char *)eth_h + l2_len); + + icmp_h = (struct icmp_hdr *)((char *)ip_h + l3_len); + if (icmp_h->icmp_type != IP_ICMP_ECHO_REQUEST && + icmp_h->icmp_type != ICMP_TIMESTAMP) + goto drop_pkt; + + icmp_pkt = (struct icmp_pkt *)icmp_h; + + ether_addr_copy(ð_h->s_addr, ð_addr); + ether_addr_copy(ð_h->d_addr, ð_h->s_addr); + ether_addr_copy(ð_addr, ð_h->d_addr); + + /* + * Similar to Linux implementation, we silently drop the broadcast or + * multicast ICMP pakcets. + * + * RFC 1122: 3.2.2.6 An ICMP_ECHO to broadcast MAY be + * silently ignored. + * RFC 1122: 3.2.2.8 An ICMP_TIMESTAMP MAY be silently + * discarded if to broadcast/multicast. + */ + ip_addr = rte_be_to_cpu_32(ip_h->dst_addr); + if (IS_IPV4_MCAST(ip_addr) || IS_IPV4_BCAST(ip_addr)) + goto drop_pkt; + + ip_addr = ip_h->src_addr; + ip_h->src_addr = ip_h->dst_addr; + ip_h->dst_addr = ip_addr; + + if (icmp_h->icmp_type == IP_ICMP_ECHO_REQUEST && + icmp_h->icmp_code == 0) { + + /* Must clear checksum field before calling the helper. */ + ip_h->hdr_checksum = 0; + ip_h->hdr_checksum = rte_ipv4_cksum(ip_h); + + icmp_h->icmp_type = IP_ICMP_ECHO_REPLY; + icmp_h->icmp_code = 0; + + /* + * Fix me: the data part of an ICMP echo request/reply + * message is implementation specific, we don't know + * how to verify or calculate the checksum. + * + * Need to see BSD or LINUX implementation. + */ + cksum = ~icmp_h->icmp_cksum & 0xffff; + cksum += ~rte_cpu_to_be_16(IP_ICMP_ECHO_REQUEST << 8) & 0xffff; + cksum += rte_cpu_to_be_16(IP_ICMP_ECHO_REPLY << 8); + cksum = (cksum & 0xffff) + (cksum >> 16); + cksum = (cksum & 0xffff) + (cksum >> 16); + icmp_h->icmp_cksum = ~cksum; + + } else if (icmp_h->icmp_type == ICMP_TIMESTAMP && + icmp_h->icmp_code == 0) { + + /* + * RFC 1122: 3.2.2.8 MAY implement ICMP timestamp requests. + * SHOULD be in the kernel for minimum random latency. + * MUST be accurate to a few minutes. + * MUST be updated at least at 15Hz. + */ + icmp_h->icmp_type = ICMP_TIMESTAMPREPLY; + icmp_h->icmp_code = 0; + icmp_pkt->times[1] = current_timestamp(); + icmp_pkt->times[2] = icmp_pkt->times[1]; + + icmp_h->icmp_cksum = 0; + /* the data part of an ICMP timestamp reply is 12 bytes. */ + icmp_h->icmp_cksum = icmp_cksum(icmp_h, 12); + } else + goto drop_pkt; + + if (pkt->pkt_len < ETHER_MIN_LEN) + rte_pktmbuf_append(pkt, ETHER_MIN_LEN - pkt->pkt_len); + + if (rte_eth_tx_burst(ctx->port_id, ctx->queue_id, &pkt, 1)) + GLUE_LOG(DEBUG, "Send ICMP echo reply OK"); + + return NULL; + +drop_pkt: + rte_pktmbuf_free(pkt); + return NULL; +} + +/** + * Receive and handle an ICMPv6 packet. + * + * @param ctx + * The pointer to the glue context. + * @param pkt + * The pointer to the raw packet data. + * @param l2_len + * The the size of the l2 header. + * @return + * MUST return NULL now. :-) + */ +struct rte_mbuf * +icmp6_recv(struct glue_ctx *ctx, struct rte_mbuf *pkt, + uint32_t l2_len, uint32_t l3_len) +{ + struct ether_addr eth_addr; + struct ether_hdr *eth_h; + struct icmp6_hdr *icmp6_h; + struct ipv6_hdr *ipv6_h; + struct in6_addr ipv6_addr; + uint32_t cksum; + + eth_h = rte_pktmbuf_mtod(pkt, struct ether_hdr *); + ipv6_h = (struct ipv6_hdr *) ((char *)eth_h + l2_len); + + icmp6_h = (struct icmp6_hdr *)((char *)ipv6_h + l3_len); + + /* NDP pkt */ + if ((icmp6_h->icmp6_type == ND_NEIGHBOR_SOLICIT || + icmp6_h->icmp6_type == ND_NEIGHBOR_ADVERT) && + icmp6_h->icmp6_code == 0) + return ndp_recv(ctx, pkt, l2_len, l3_len); + + /* only support ECHO now, other types of pkts are dropped */ + if ((icmp6_h->icmp6_type != ICMP6_ECHO_REQUEST && + icmp6_h->icmp6_type != ICMP6_ECHO_REPLY) || + icmp6_h->icmp6_code != 0) + goto drop_pkt; + + ether_addr_copy(ð_h->s_addr, ð_addr); + ether_addr_copy(ð_h->d_addr, ð_h->s_addr); + ether_addr_copy(ð_addr, ð_h->d_addr); + + /* + * Now, we silently drop the anycast or multicast ICMP pakcets. + * But it does not conform to RFC 4443. Maybe fix it latter. + * + * RFC 4443: 4.2 An Echo Reply SHOULD be sent in response to an + * Echo Request message sent to an IPv6 multicast or anycast address. + * In this case, thesource address of the reply MUST be a unicast + * address belonging to the interface on which the Echo Request + * message was received. + */ + switch (icmp6_h->icmp6_type) { + case ICMP6_ECHO_REQUEST: + if (memcmp(ipv6_h->dst_addr, &ctx->ipv6, + sizeof(struct in6_addr)) != 0) + goto drop_pkt; + + rte_memcpy(&ipv6_addr, ipv6_h->src_addr, + sizeof(struct in6_addr)); + rte_memcpy(ipv6_h->src_addr, ipv6_h->dst_addr, + sizeof(struct in6_addr)); + rte_memcpy(ipv6_h->dst_addr, &ipv6_addr, + sizeof(struct in6_addr)); + + icmp6_h->icmp6_type = ICMP6_ECHO_REPLY; + + cksum = ~icmp6_h->icmp6_cksum & 0xffff; + cksum += ~rte_cpu_to_be_16(ICMP6_ECHO_REQUEST << 8) & 0xffff; + cksum += rte_cpu_to_be_16(ICMP6_ECHO_REPLY << 8); + cksum = (cksum & 0xffff) + (cksum >> 16); + cksum = (cksum & 0xffff) + (cksum >> 16); + icmp6_h->icmp6_cksum = ~cksum; + + break; + default: + goto drop_pkt; + } + + if (pkt->pkt_len < ETHER_MIN_LEN) + rte_pktmbuf_append(pkt, ETHER_MIN_LEN - pkt->pkt_len); + + if (rte_eth_tx_burst(ctx->port_id, ctx->queue_id, &pkt, 1)) + GLUE_LOG(DEBUG, "Send ICMP echo reply OK"); + + return NULL; + +drop_pkt: + rte_pktmbuf_free(pkt); + return NULL; +} |