* [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table @ 2011-08-01 16:18 Fabien Chouteau 2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau 2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka 0 siblings, 2 replies; 8+ messages in thread From: Fabien Chouteau @ 2011-08-01 16:18 UTC (permalink / raw) To: qemu-devel; +Cc: jan.kiszka This patch adds a simple ARP table in Slirp and also adds handling of gratuitous ARP requests. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> --- Makefile.objs | 2 +- slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++ slirp/bootp.c | 21 +++++++++------ slirp/slirp.c | 63 +++++++++++---------------------------------- slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++-- 5 files changed, 146 insertions(+), 59 deletions(-) create mode 100644 slirp/arp_table.c diff --git a/Makefile.objs b/Makefile.objs index 6991a9f..0c10557 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) # xen backend driver support diff --git a/slirp/arp_table.c b/slirp/arp_table.c new file mode 100644 index 0000000..c7034ee --- /dev/null +++ b/slirp/arp_table.c @@ -0,0 +1,72 @@ +#include "slirp.h" + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_add"); + DEBUG_ARG("ip = 0x%x", ip_addr); + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + ethaddr[0], ethaddr[1], ethaddr[2], + ethaddr[3], ethaddr[4], ethaddr[5])); + + if ((ip_addr & ~(0xf << 28)) == 0 || + ip_addr == broadcast_addr) { + /* Do not register 0.0.0.0/8 or broadcast addresses */ + return; + } + + /* Search for an entry */ + for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) { + if (arptbl->table[i].ar_sip == ip_addr) { + /* Update the entry */ + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); + return; + } + } + + /* No entry found, create a new one */ + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; +} + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_search"); + DEBUG_ARG("ip = 0x%x", in_ip_addr); + + /* If address in 0.0.0.0/8 */ + if ((in_ip_addr & ~(0xf << 28)) == 0) { + /* Invalid address */ + return 0; + } + + /* If broadcast address */ + if (in_ip_addr == broadcast_addr) { + /* return Ethernet broadcast address */ + memset(out_ethaddr, 0xff, ETH_ALEN); + return 1; + } + + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if (arptbl->table[i].ar_sip == in_ip_addr) { + memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN); + DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + out_ethaddr[0], out_ethaddr[1], out_ethaddr[2], + out_ethaddr[3], out_ethaddr[4], out_ethaddr[5])); + return 1; + } + } + + return 0; +} diff --git a/slirp/bootp.c b/slirp/bootp.c index 1eb2ed1..efd1fe7 100644 --- a/slirp/bootp.c +++ b/slirp/bootp.c @@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) struct in_addr preq_addr; int dhcp_msg_type, val; uint8_t *q; + uint8_t client_ethaddr[ETH_ALEN]; /* extract exact DHCP msg type */ dhcp_decode(bp, &dhcp_msg_type, &preq_addr); @@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type != DHCPDISCOVER && dhcp_msg_type != DHCPREQUEST) return; - /* XXX: this is a hack to get the client mac address */ - memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6); + + /* Get client's hardware address from bootp request */ + memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN); m = m_get(slirp); if (!m) { @@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type == DHCPDISCOVER) { if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; } } if (!bc) { new_addr: - bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr); + bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr); if (!bc) { DPRINTF("no address left\n"); return; } } - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else { daddr.sin_addr.s_addr = 0; } @@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) } } + /* Update ARP table for this IP address */ + arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr); + saddr.sin_addr = slirp->vhost_addr; saddr.sin_port = htons(BOOTP_SERVER); @@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) rbp->bp_xid = bp->bp_xid; rbp->bp_htype = 1; rbp->bp_hlen = 6; - memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6); + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN); rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */ rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */ diff --git a/slirp/slirp.c b/slirp/slirp.c index df787ea..4a9a4d5 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -31,11 +31,11 @@ struct in_addr loopback_addr; /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */ -static const uint8_t special_ethaddr[6] = { +static const uint8_t special_ethaddr[ETH_ALEN] = { 0x52, 0x55, 0x00, 0x00, 0x00, 0x00 }; -static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 }; +static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; /* XXX: suppress those select globals */ fd_set *global_readfds, *global_writefds, *global_xfds; @@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, global_xfds = NULL; } -#define ETH_ALEN 6 -#define ETH_HLEN 14 - -#define ETH_P_IP 0x0800 /* Internet Protocol packet */ -#define ETH_P_ARP 0x0806 /* Address Resolution packet */ - -#define ARPOP_REQUEST 1 /* ARP request */ -#define ARPOP_REPLY 2 /* ARP reply */ - -struct ethhdr -{ - unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ - unsigned char h_source[ETH_ALEN]; /* source ether addr */ - unsigned short h_proto; /* packet type ID field */ -}; - -struct arphdr -{ - unsigned short ar_hrd; /* format of hardware address */ - unsigned short ar_pro; /* format of protocol address */ - unsigned char ar_hln; /* length of hardware address */ - unsigned char ar_pln; /* length of protocol address */ - unsigned short ar_op; /* ARP opcode (command) */ - - /* - * Ethernet looks like this : This bit is variable sized however... - */ - unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ - uint32_t ar_sip; /* sender IP address */ - unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ - uint32_t ar_tip ; /* target IP address */ -} __attribute__((packed)); - static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) { - struct ethhdr *eh = (struct ethhdr *)pkt; struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)]; struct ethhdr *reh = (struct ethhdr *)arp_reply; @@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) ar_op = ntohs(ah->ar_op); switch(ar_op) { case ARPOP_REQUEST: + if (ah->ar_tip == ah->ar_sip) { + /* Gratuitous ARP */ + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); + return; + } + if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { if (ah->ar_tip == slirp->vnameserver_addr.s_addr || @@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) return; arp_ok: memset(arp_reply, 0, sizeof(arp_reply)); - /* XXX: make an ARP request to have the client address */ - memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN); + + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); /* ARP request for alias/dns mac address */ memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); @@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) } break; case ARPOP_REPLY: - /* reply to request of client mac address ? */ - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) && - ah->ar_sip == slirp->client_ipaddr.s_addr) { - memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN); - } + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); break; default: break; @@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) { uint8_t buf[1600]; struct ethhdr *eh = (struct ethhdr *)buf; + uint8_t ethaddr[ETH_ALEN]; + const struct ip *iph = (const struct ip *)ip_data; if (ip_data_len + ETH_HLEN > sizeof(buf)) return; - - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) { + + if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; struct ethhdr *reh = (struct ethhdr *)arp_req; struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); - const struct ip *iph = (const struct ip *)ip_data; /* If the client addr is not known, there is no point in sending the packet to it. Normally the sender should have @@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) slirp->client_ipaddr = iph->ip_dst; slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); } else { - memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN); + memcpy(eh->h_dest, ethaddr, ETH_ALEN); memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); /* XXX: not correct */ memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); diff --git a/slirp/slirp.h b/slirp/slirp.h index 16bb6ba..2a070e6 100644 --- a/slirp/slirp.h +++ b/slirp/slirp.h @@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia); /* osdep.c */ int qemu_socket(int domain, int type, int protocol); +#define ETH_ALEN 6 +#define ETH_HLEN 14 + +#define ETH_P_IP 0x0800 /* Internet Protocol packet */ +#define ETH_P_ARP 0x0806 /* Address Resolution packet */ + +#define ARPOP_REQUEST 1 /* ARP request */ +#define ARPOP_REPLY 2 /* ARP reply */ + +struct ethhdr { + unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ + unsigned char h_source[ETH_ALEN]; /* source ether addr */ + unsigned short h_proto; /* packet type ID field */ +}; + +struct arphdr { + unsigned short ar_hrd; /* format of hardware address */ + unsigned short ar_pro; /* format of protocol address */ + unsigned char ar_hln; /* length of hardware address */ + unsigned char ar_pln; /* length of protocol address */ + unsigned short ar_op; /* ARP opcode (command) */ + + /* + * Ethernet looks like this : This bit is variable sized however... + */ + unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ + uint32_t ar_sip; /* sender IP address */ + unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ + uint32_t ar_tip; /* target IP address */ +} __attribute__((packed)); + +#define ARP_TABLE_SIZE 16 + +typedef struct ArpTable { + struct arphdr table[ARP_TABLE_SIZE]; + int next_victim; +} ArpTable; + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]); + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]); struct Slirp { QTAILQ_ENTRY(Slirp) entry; @@ -181,9 +223,6 @@ struct Slirp { struct in_addr vdhcp_startaddr; struct in_addr vnameserver_addr; - /* ARP cache for the guest IP addresses (XXX: allow many entries) */ - uint8_t client_ethaddr[6]; - struct in_addr client_ipaddr; char client_hostname[33]; @@ -227,6 +266,8 @@ struct Slirp { char *tftp_prefix; struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX]; + ArpTable arp_table; + void *opaque; }; -- 1.7.4.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets 2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau @ 2011-08-01 16:18 ` Fabien Chouteau 2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka 1 sibling, 0 replies; 8+ messages in thread From: Fabien Chouteau @ 2011-08-01 16:18 UTC (permalink / raw) To: qemu-devel; +Cc: jan.kiszka In the current implementation, if Slirp tries to send an IP packet to a client with an unknown hardware address, the packet is simply dropped and an ARP request is sent (if_encap in slirp/slirp.c). With this patch, Slirp will send the ARP request, re-queue the packet and try to send it later. The packet is dropped after one second if the ARP reply is not received. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> --- slirp/if.c | 28 +++++++++++++++++++--- slirp/main.h | 2 +- slirp/mbuf.c | 2 + slirp/mbuf.h | 2 + slirp/slirp.c | 72 +++++++++++++++++++++++++++++++------------------------- 5 files changed, 69 insertions(+), 37 deletions(-) diff --git a/slirp/if.c b/slirp/if.c index 0f04e13..2d79e45 100644 --- a/slirp/if.c +++ b/slirp/if.c @@ -6,6 +6,7 @@ */ #include <slirp.h> +#include "qemu-timer.h" #define ifs_init(ifm) ((ifm)->ifs_next = (ifm)->ifs_prev = (ifm)) @@ -105,6 +106,9 @@ if_output(struct socket *so, struct mbuf *ifm) ifs_init(ifm); insque(ifm, ifq); + /* Expiration date = Now + 1 second */ + ifm->expiration_date = qemu_get_clock_ns(rt_clock) + 1000000000ULL; + diddit: slirp->if_queued++; @@ -153,6 +157,9 @@ diddit: void if_start(Slirp *slirp) { + int requeued = 0; + uint64_t now; + struct mbuf *ifm, *ifqt; DEBUG_CALL("if_start"); @@ -165,6 +172,8 @@ if_start(Slirp *slirp) if (!slirp_can_output(slirp->opaque)) return; + now = qemu_get_clock_ns(rt_clock); + /* * See which queue to get next packet from * If there's something in the fastq, select it immediately @@ -199,11 +208,22 @@ if_start(Slirp *slirp) ifm->ifq_so->so_nqueued = 0; } - /* Encapsulate the packet for sending */ - if_encap(slirp, (uint8_t *)ifm->m_data, ifm->m_len); - - m_free(ifm); + if (ifm->expiration_date < now) { + /* Expired */ + m_free(ifm); + } else { + /* Encapsulate the packet for sending */ + if (if_encap(slirp, ifm)) { + m_free(ifm); + } else { + /* re-queue */ + insque(ifm, ifqt); + requeued++; + } + } if (slirp->if_queued) goto again; + + slirp->if_queued = requeued; } diff --git a/slirp/main.h b/slirp/main.h index 0dd8d81..028df4b 100644 --- a/slirp/main.h +++ b/slirp/main.h @@ -42,5 +42,5 @@ extern int tcp_keepintvl; #define PROTO_PPP 0x2 #endif -void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len); +int if_encap(Slirp *slirp, struct mbuf *ifm); ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags); diff --git a/slirp/mbuf.c b/slirp/mbuf.c index ce2eb84..c699c75 100644 --- a/slirp/mbuf.c +++ b/slirp/mbuf.c @@ -70,6 +70,8 @@ m_get(Slirp *slirp) m->m_len = 0; m->m_nextpkt = NULL; m->m_prevpkt = NULL; + m->arp_requested = false; + m->expiration_date = (uint64_t)-1; end_error: DEBUG_ARG("m = %lx", (long )m); return m; diff --git a/slirp/mbuf.h b/slirp/mbuf.h index b74544b..55170e5 100644 --- a/slirp/mbuf.h +++ b/slirp/mbuf.h @@ -86,6 +86,8 @@ struct mbuf { char m_dat_[1]; /* ANSI don't like 0 sized arrays */ char *m_ext_; } M_dat; + bool arp_requested; + uint64_t expiration_date; }; #define m_next m_hdr.mh_next diff --git a/slirp/slirp.c b/slirp/slirp.c index 4a9a4d5..a86cc6e 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -692,55 +692,63 @@ void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) } } -/* output the IP packet to the ethernet device */ -void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) +/* Output the IP packet to the ethernet device. Returns 0 if the packet must be + * re-queued. + */ +int if_encap(Slirp *slirp, struct mbuf *ifm) { uint8_t buf[1600]; struct ethhdr *eh = (struct ethhdr *)buf; uint8_t ethaddr[ETH_ALEN]; - const struct ip *iph = (const struct ip *)ip_data; + const struct ip *iph = (const struct ip *)ifm->m_data; - if (ip_data_len + ETH_HLEN > sizeof(buf)) - return; + if (ifm->m_len + ETH_HLEN > sizeof(buf)) { + return 1; + } if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; struct ethhdr *reh = (struct ethhdr *)arp_req; struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); - /* If the client addr is not known, there is no point in - sending the packet to it. Normally the sender should have - done an ARP request to get its MAC address. Here we do it - in place of sending the packet and we hope that the sender - will retry sending its packet. */ - memset(reh->h_dest, 0xff, ETH_ALEN); - memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4); - memcpy(&reh->h_source[2], &slirp->vhost_addr, 4); - reh->h_proto = htons(ETH_P_ARP); - rah->ar_hrd = htons(1); - rah->ar_pro = htons(ETH_P_IP); - rah->ar_hln = ETH_ALEN; - rah->ar_pln = 4; - rah->ar_op = htons(ARPOP_REQUEST); - /* source hw addr */ - memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4); - memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4); - /* source IP */ - rah->ar_sip = slirp->vhost_addr.s_addr; - /* target hw addr (none) */ - memset(rah->ar_tha, 0, ETH_ALEN); - /* target IP */ - rah->ar_tip = iph->ip_dst.s_addr; - slirp->client_ipaddr = iph->ip_dst; - slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); + if (!ifm->arp_requested) { + /* If the client addr is not known, send an ARP request */ + memset(reh->h_dest, 0xff, ETH_ALEN); + memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4); + memcpy(&reh->h_source[2], &slirp->vhost_addr, 4); + reh->h_proto = htons(ETH_P_ARP); + rah->ar_hrd = htons(1); + rah->ar_pro = htons(ETH_P_IP); + rah->ar_hln = ETH_ALEN; + rah->ar_pln = 4; + rah->ar_op = htons(ARPOP_REQUEST); + + /* source hw addr */ + memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4); + memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4); + + /* source IP */ + rah->ar_sip = slirp->vhost_addr.s_addr; + + /* target hw addr (none) */ + memset(rah->ar_tha, 0, ETH_ALEN); + + /* target IP */ + rah->ar_tip = iph->ip_dst.s_addr; + slirp->client_ipaddr = iph->ip_dst; + slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); + ifm->arp_requested = true; + } + return 0; } else { memcpy(eh->h_dest, ethaddr, ETH_ALEN); memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); /* XXX: not correct */ memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); eh->h_proto = htons(ETH_P_IP); - memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); - slirp_output(slirp->opaque, buf, ip_data_len + ETH_HLEN); + memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len); + slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN); + return 1; } } -- 1.7.4.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table 2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau 2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau @ 2011-08-01 20:16 ` Jan Kiszka 2011-08-02 9:58 ` Fabien Chouteau 2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau 1 sibling, 2 replies; 8+ messages in thread From: Jan Kiszka @ 2011-08-01 20:16 UTC (permalink / raw) To: Fabien Chouteau; +Cc: qemu-devel [-- Attachment #1: Type: text/plain, Size: 3582 bytes --] On 2011-08-01 18:18, Fabien Chouteau wrote: > This patch adds a simple ARP table in Slirp and also adds handling of > gratuitous ARP requests. > > Signed-off-by: Fabien Chouteau <chouteau@adacore.com> > --- > Makefile.objs | 2 +- > slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > slirp/bootp.c | 21 +++++++++------ > slirp/slirp.c | 63 +++++++++++---------------------------------- > slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++-- > 5 files changed, 146 insertions(+), 59 deletions(-) > create mode 100644 slirp/arp_table.c > > diff --git a/Makefile.objs b/Makefile.objs > index 6991a9f..0c10557 100644 > --- a/Makefile.objs > +++ b/Makefile.objs > @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o > > slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o > slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o > -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o > +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o > common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) > > # xen backend driver support > diff --git a/slirp/arp_table.c b/slirp/arp_table.c > new file mode 100644 > index 0000000..c7034ee > --- /dev/null > +++ b/slirp/arp_table.c > @@ -0,0 +1,72 @@ > +#include "slirp.h" > + > +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) > +{ > + const in_addr_t broadcast_addr = > + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; That's only part of the picture. 255.255.255.255 is a valid broadcast address as well. > + ArpTable *arptbl = &slirp->arp_table; > + int i; > + > + DEBUG_CALL("arp_table_add"); > + DEBUG_ARG("ip = 0x%x", ip_addr); > + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", > + ethaddr[0], ethaddr[1], ethaddr[2], > + ethaddr[3], ethaddr[4], ethaddr[5])); > + > + if ((ip_addr & ~(0xf << 28)) == 0 || > + ip_addr == broadcast_addr) { > + /* Do not register 0.0.0.0/8 or broadcast addresses */ > + return; > + } > + > + /* Search for an entry */ > + for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) { Forgot to remove the test for ar_sip != 0. > + if (arptbl->table[i].ar_sip == ip_addr) { > + /* Update the entry */ > + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); > + return; > + } > + } > + > + /* No entry found, create a new one */ > + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; > + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); > + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; > +} > + > +bool arp_table_search(Slirp *slirp, int in_ip_addr, > + uint8_t out_ethaddr[ETH_ALEN]) > +{ > + const in_addr_t broadcast_addr = > + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; Same as above. That means DCHP is still broken. Please include that scenario in your tests before sending the next round. > + ArpTable *arptbl = &slirp->arp_table; > + int i; > + > + DEBUG_CALL("arp_table_search"); > + DEBUG_ARG("ip = 0x%x", in_ip_addr); > + > + /* If address in 0.0.0.0/8 */ > + if ((in_ip_addr & ~(0xf << 28)) == 0) { Should rather be an assert() as it means the caller is about to send a frame to that source-only address. Jan [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 262 bytes --] ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table 2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka @ 2011-08-02 9:58 ` Fabien Chouteau 2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau 1 sibling, 0 replies; 8+ messages in thread From: Fabien Chouteau @ 2011-08-02 9:58 UTC (permalink / raw) To: Jan Kiszka; +Cc: qemu-devel On 01/08/2011 22:16, Jan Kiszka wrote: > On 2011-08-01 18:18, Fabien Chouteau wrote: >> This patch adds a simple ARP table in Slirp and also adds handling of >> gratuitous ARP requests. >> >> Signed-off-by: Fabien Chouteau <chouteau@adacore.com> >> --- >> Makefile.objs | 2 +- >> slirp/arp_table.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++ >> slirp/bootp.c | 21 +++++++++------ >> slirp/slirp.c | 63 +++++++++++---------------------------------- >> slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++-- >> 5 files changed, 146 insertions(+), 59 deletions(-) >> create mode 100644 slirp/arp_table.c >> >> diff --git a/Makefile.objs b/Makefile.objs >> index 6991a9f..0c10557 100644 >> --- a/Makefile.objs >> +++ b/Makefile.objs >> @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o >> >> slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o >> slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o >> -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o >> +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o >> common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) >> >> # xen backend driver support >> diff --git a/slirp/arp_table.c b/slirp/arp_table.c >> new file mode 100644 >> index 0000000..c7034ee >> --- /dev/null >> +++ b/slirp/arp_table.c >> @@ -0,0 +1,72 @@ >> +#include "slirp.h" >> + >> +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) >> +{ >> + const in_addr_t broadcast_addr = >> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; > > That's only part of the picture. 255.255.255.255 is a valid broadcast > address as well. Of course, how can I have missed this... >> + ArpTable *arptbl = &slirp->arp_table; >> + int i; >> + >> + DEBUG_CALL("arp_table_add"); >> + DEBUG_ARG("ip = 0x%x", ip_addr); >> + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", >> + ethaddr[0], ethaddr[1], ethaddr[2], >> + ethaddr[3], ethaddr[4], ethaddr[5])); >> + >> + if ((ip_addr & ~(0xf << 28)) == 0 || >> + ip_addr == broadcast_addr) { >> + /* Do not register 0.0.0.0/8 or broadcast addresses */ >> + return; >> + } >> + >> + /* Search for an entry */ >> + for (i = 0; i < ARP_TABLE_SIZE && arptbl->table[i].ar_sip != 0; i++) { > > Forgot to remove the test for ar_sip != 0. > >> + if (arptbl->table[i].ar_sip == ip_addr) { >> + /* Update the entry */ >> + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); >> + return; >> + } >> + } >> + >> + /* No entry found, create a new one */ >> + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; >> + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); >> + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; >> +} >> + >> +bool arp_table_search(Slirp *slirp, int in_ip_addr, >> + uint8_t out_ethaddr[ETH_ALEN]) >> +{ >> + const in_addr_t broadcast_addr = >> + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; > > Same as above. That means DCHP is still broken. Please include that > scenario in your tests before sending the next round. OK I will test with DHCP. Thanks again, -- Fabien Chouteau ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table 2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka 2011-08-02 9:58 ` Fabien Chouteau @ 2011-08-02 13:19 ` Fabien Chouteau 2011-08-03 9:13 ` Jan Kiszka 1 sibling, 1 reply; 8+ messages in thread From: Fabien Chouteau @ 2011-08-02 13:19 UTC (permalink / raw) To: qemu-devel; +Cc: jan.kiszka This patch adds a simple ARP table in Slirp and also adds handling of gratuitous ARP requests. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> --- Makefile.objs | 2 +- slirp/arp_table.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++ slirp/bootp.c | 21 +++++++++------ slirp/slirp.c | 63 ++++++++++++----------------------------------- slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++-- 5 files changed, 145 insertions(+), 59 deletions(-) create mode 100644 slirp/arp_table.c diff --git a/Makefile.objs b/Makefile.objs index 6991a9f..0c10557 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) # xen backend driver support diff --git a/slirp/arp_table.c b/slirp/arp_table.c new file mode 100644 index 0000000..c259b42 --- /dev/null +++ b/slirp/arp_table.c @@ -0,0 +1,71 @@ +#include "slirp.h" + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_add"); + DEBUG_ARG("ip = 0x%x", ip_addr); + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + ethaddr[0], ethaddr[1], ethaddr[2], + ethaddr[3], ethaddr[4], ethaddr[5])); + + /* Check 0.0.0.0/8 invalid source-only addresses */ + assert((ip_addr & htonl(~(0xf << 28))) != 0); + + if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) { + /* Do not register broadcast addresses */ + return; + } + + /* Search for an entry */ + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if (arptbl->table[i].ar_sip == ip_addr) { + /* Update the entry */ + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); + return; + } + } + + /* No entry found, create a new one */ + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; +} + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_search"); + DEBUG_ARG("ip = 0x%x", in_ip_addr); + + /* Check 0.0.0.0/8 invalid source-only addresses */ + assert((in_ip_addr & htonl(~(0xf << 28))) != 0); + + /* If broadcast address */ + if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) { + /* return Ethernet broadcast address */ + memset(out_ethaddr, 0xff, ETH_ALEN); + return 1; + } + + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if (arptbl->table[i].ar_sip == in_ip_addr) { + memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN); + DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + out_ethaddr[0], out_ethaddr[1], out_ethaddr[2], + out_ethaddr[3], out_ethaddr[4], out_ethaddr[5])); + return 1; + } + } + + return 0; +} diff --git a/slirp/bootp.c b/slirp/bootp.c index 1eb2ed1..efd1fe7 100644 --- a/slirp/bootp.c +++ b/slirp/bootp.c @@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) struct in_addr preq_addr; int dhcp_msg_type, val; uint8_t *q; + uint8_t client_ethaddr[ETH_ALEN]; /* extract exact DHCP msg type */ dhcp_decode(bp, &dhcp_msg_type, &preq_addr); @@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type != DHCPDISCOVER && dhcp_msg_type != DHCPREQUEST) return; - /* XXX: this is a hack to get the client mac address */ - memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6); + + /* Get client's hardware address from bootp request */ + memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN); m = m_get(slirp); if (!m) { @@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type == DHCPDISCOVER) { if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; } } if (!bc) { new_addr: - bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr); + bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr); if (!bc) { DPRINTF("no address left\n"); return; } } - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else { daddr.sin_addr.s_addr = 0; } @@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) } } + /* Update ARP table for this IP address */ + arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr); + saddr.sin_addr = slirp->vhost_addr; saddr.sin_port = htons(BOOTP_SERVER); @@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) rbp->bp_xid = bp->bp_xid; rbp->bp_htype = 1; rbp->bp_hlen = 6; - memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6); + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN); rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */ rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */ diff --git a/slirp/slirp.c b/slirp/slirp.c index df787ea..4a9a4d5 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -31,11 +31,11 @@ struct in_addr loopback_addr; /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */ -static const uint8_t special_ethaddr[6] = { +static const uint8_t special_ethaddr[ETH_ALEN] = { 0x52, 0x55, 0x00, 0x00, 0x00, 0x00 }; -static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 }; +static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; /* XXX: suppress those select globals */ fd_set *global_readfds, *global_writefds, *global_xfds; @@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, global_xfds = NULL; } -#define ETH_ALEN 6 -#define ETH_HLEN 14 - -#define ETH_P_IP 0x0800 /* Internet Protocol packet */ -#define ETH_P_ARP 0x0806 /* Address Resolution packet */ - -#define ARPOP_REQUEST 1 /* ARP request */ -#define ARPOP_REPLY 2 /* ARP reply */ - -struct ethhdr -{ - unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ - unsigned char h_source[ETH_ALEN]; /* source ether addr */ - unsigned short h_proto; /* packet type ID field */ -}; - -struct arphdr -{ - unsigned short ar_hrd; /* format of hardware address */ - unsigned short ar_pro; /* format of protocol address */ - unsigned char ar_hln; /* length of hardware address */ - unsigned char ar_pln; /* length of protocol address */ - unsigned short ar_op; /* ARP opcode (command) */ - - /* - * Ethernet looks like this : This bit is variable sized however... - */ - unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ - uint32_t ar_sip; /* sender IP address */ - unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ - uint32_t ar_tip ; /* target IP address */ -} __attribute__((packed)); - static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) { - struct ethhdr *eh = (struct ethhdr *)pkt; struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)]; struct ethhdr *reh = (struct ethhdr *)arp_reply; @@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) ar_op = ntohs(ah->ar_op); switch(ar_op) { case ARPOP_REQUEST: + if (ah->ar_tip == ah->ar_sip) { + /* Gratuitous ARP */ + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); + return; + } + if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { if (ah->ar_tip == slirp->vnameserver_addr.s_addr || @@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) return; arp_ok: memset(arp_reply, 0, sizeof(arp_reply)); - /* XXX: make an ARP request to have the client address */ - memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN); + + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); /* ARP request for alias/dns mac address */ memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); @@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) } break; case ARPOP_REPLY: - /* reply to request of client mac address ? */ - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) && - ah->ar_sip == slirp->client_ipaddr.s_addr) { - memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN); - } + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); break; default: break; @@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) { uint8_t buf[1600]; struct ethhdr *eh = (struct ethhdr *)buf; + uint8_t ethaddr[ETH_ALEN]; + const struct ip *iph = (const struct ip *)ip_data; if (ip_data_len + ETH_HLEN > sizeof(buf)) return; - - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) { + + if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; struct ethhdr *reh = (struct ethhdr *)arp_req; struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); - const struct ip *iph = (const struct ip *)ip_data; /* If the client addr is not known, there is no point in sending the packet to it. Normally the sender should have @@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) slirp->client_ipaddr = iph->ip_dst; slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); } else { - memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN); + memcpy(eh->h_dest, ethaddr, ETH_ALEN); memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); /* XXX: not correct */ memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); diff --git a/slirp/slirp.h b/slirp/slirp.h index 16bb6ba..2a070e6 100644 --- a/slirp/slirp.h +++ b/slirp/slirp.h @@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia); /* osdep.c */ int qemu_socket(int domain, int type, int protocol); +#define ETH_ALEN 6 +#define ETH_HLEN 14 + +#define ETH_P_IP 0x0800 /* Internet Protocol packet */ +#define ETH_P_ARP 0x0806 /* Address Resolution packet */ + +#define ARPOP_REQUEST 1 /* ARP request */ +#define ARPOP_REPLY 2 /* ARP reply */ + +struct ethhdr { + unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ + unsigned char h_source[ETH_ALEN]; /* source ether addr */ + unsigned short h_proto; /* packet type ID field */ +}; + +struct arphdr { + unsigned short ar_hrd; /* format of hardware address */ + unsigned short ar_pro; /* format of protocol address */ + unsigned char ar_hln; /* length of hardware address */ + unsigned char ar_pln; /* length of protocol address */ + unsigned short ar_op; /* ARP opcode (command) */ + + /* + * Ethernet looks like this : This bit is variable sized however... + */ + unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ + uint32_t ar_sip; /* sender IP address */ + unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ + uint32_t ar_tip; /* target IP address */ +} __attribute__((packed)); + +#define ARP_TABLE_SIZE 16 + +typedef struct ArpTable { + struct arphdr table[ARP_TABLE_SIZE]; + int next_victim; +} ArpTable; + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]); + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]); struct Slirp { QTAILQ_ENTRY(Slirp) entry; @@ -181,9 +223,6 @@ struct Slirp { struct in_addr vdhcp_startaddr; struct in_addr vnameserver_addr; - /* ARP cache for the guest IP addresses (XXX: allow many entries) */ - uint8_t client_ethaddr[6]; - struct in_addr client_ipaddr; char client_hostname[33]; @@ -227,6 +266,8 @@ struct Slirp { char *tftp_prefix; struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX]; + ArpTable arp_table; + void *opaque; }; -- 1.7.4.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table 2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau @ 2011-08-03 9:13 ` Jan Kiszka 2011-08-03 10:44 ` Fabien Chouteau 2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau 0 siblings, 2 replies; 8+ messages in thread From: Jan Kiszka @ 2011-08-03 9:13 UTC (permalink / raw) To: Fabien Chouteau; +Cc: qemu-devel@nongnu.org On 2011-08-02 15:19, Fabien Chouteau wrote: > This patch adds a simple ARP table in Slirp and also adds handling of > gratuitous ARP requests. > > Signed-off-by: Fabien Chouteau <chouteau@adacore.com> > --- > Makefile.objs | 2 +- > slirp/arp_table.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > slirp/bootp.c | 21 +++++++++------ > slirp/slirp.c | 63 ++++++++++++----------------------------------- > slirp/slirp.h | 47 ++++++++++++++++++++++++++++++++-- > 5 files changed, 145 insertions(+), 59 deletions(-) > create mode 100644 slirp/arp_table.c > > diff --git a/Makefile.objs b/Makefile.objs > index 6991a9f..0c10557 100644 > --- a/Makefile.objs > +++ b/Makefile.objs > @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o > > slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o > slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o > -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o > +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o > common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) > > # xen backend driver support > diff --git a/slirp/arp_table.c b/slirp/arp_table.c > new file mode 100644 > index 0000000..c259b42 > --- /dev/null > +++ b/slirp/arp_table.c > @@ -0,0 +1,71 @@ > +#include "slirp.h" > + > +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) > +{ > + const in_addr_t broadcast_addr = > + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; > + ArpTable *arptbl = &slirp->arp_table; > + int i; > + > + DEBUG_CALL("arp_table_add"); > + DEBUG_ARG("ip = 0x%x", ip_addr); > + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", > + ethaddr[0], ethaddr[1], ethaddr[2], > + ethaddr[3], ethaddr[4], ethaddr[5])); > + > + /* Check 0.0.0.0/8 invalid source-only addresses */ > + assert((ip_addr & htonl(~(0xf << 28))) != 0); > + > + if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) { > + /* Do not register broadcast addresses */ > + return; > + } > + > + /* Search for an entry */ > + for (i = 0; i < ARP_TABLE_SIZE; i++) { > + if (arptbl->table[i].ar_sip == ip_addr) { > + /* Update the entry */ > + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); > + return; > + } > + } > + > + /* No entry found, create a new one */ > + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; > + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); > + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; > +} > + > +bool arp_table_search(Slirp *slirp, int in_ip_addr, > + uint8_t out_ethaddr[ETH_ALEN]) > +{ > + const in_addr_t broadcast_addr = > + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; > + ArpTable *arptbl = &slirp->arp_table; > + int i; > + > + DEBUG_CALL("arp_table_search"); > + DEBUG_ARG("ip = 0x%x", in_ip_addr); > + > + /* Check 0.0.0.0/8 invalid source-only addresses */ > + assert((in_ip_addr & htonl(~(0xf << 28))) != 0); > + > + /* If broadcast address */ > + if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) { > + /* return Ethernet broadcast address */ > + memset(out_ethaddr, 0xff, ETH_ALEN); > + return 1; > + } > + > + for (i = 0; i < ARP_TABLE_SIZE; i++) { > + if (arptbl->table[i].ar_sip == in_ip_addr) { > + memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN); > + DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", > + out_ethaddr[0], out_ethaddr[1], out_ethaddr[2], > + out_ethaddr[3], out_ethaddr[4], out_ethaddr[5])); > + return 1; > + } > + } > + > + return 0; > +} > diff --git a/slirp/bootp.c b/slirp/bootp.c > index 1eb2ed1..efd1fe7 100644 > --- a/slirp/bootp.c > +++ b/slirp/bootp.c > @@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) > struct in_addr preq_addr; > int dhcp_msg_type, val; > uint8_t *q; > + uint8_t client_ethaddr[ETH_ALEN]; > > /* extract exact DHCP msg type */ > dhcp_decode(bp, &dhcp_msg_type, &preq_addr); > @@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) > if (dhcp_msg_type != DHCPDISCOVER && > dhcp_msg_type != DHCPREQUEST) > return; > - /* XXX: this is a hack to get the client mac address */ > - memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6); > + > + /* Get client's hardware address from bootp request */ > + memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN); > > m = m_get(slirp); > if (!m) { > @@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) > > if (dhcp_msg_type == DHCPDISCOVER) { > if (preq_addr.s_addr != htonl(0L)) { > - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); > + bc = request_addr(slirp, &preq_addr, client_ethaddr); > if (bc) { > daddr.sin_addr = preq_addr; > } > } > if (!bc) { > new_addr: > - bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr); > + bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr); > if (!bc) { > DPRINTF("no address left\n"); > return; > } > } > - memcpy(bc->macaddr, slirp->client_ethaddr, 6); > + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); > } else if (preq_addr.s_addr != htonl(0L)) { > - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); > + bc = request_addr(slirp, &preq_addr, client_ethaddr); > if (bc) { > daddr.sin_addr = preq_addr; > - memcpy(bc->macaddr, slirp->client_ethaddr, 6); > + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); > } else { > daddr.sin_addr.s_addr = 0; > } > @@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) > } > } > > + /* Update ARP table for this IP address */ > + arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr); > + > saddr.sin_addr = slirp->vhost_addr; > saddr.sin_port = htons(BOOTP_SERVER); > > @@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) > rbp->bp_xid = bp->bp_xid; > rbp->bp_htype = 1; > rbp->bp_hlen = 6; > - memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6); > + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN); > > rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */ > rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */ > diff --git a/slirp/slirp.c b/slirp/slirp.c > index df787ea..4a9a4d5 100644 > --- a/slirp/slirp.c > +++ b/slirp/slirp.c > @@ -31,11 +31,11 @@ > struct in_addr loopback_addr; > > /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */ > -static const uint8_t special_ethaddr[6] = { > +static const uint8_t special_ethaddr[ETH_ALEN] = { > 0x52, 0x55, 0x00, 0x00, 0x00, 0x00 > }; > > -static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 }; > +static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; > > /* XXX: suppress those select globals */ > fd_set *global_readfds, *global_writefds, *global_xfds; > @@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, > global_xfds = NULL; > } > > -#define ETH_ALEN 6 > -#define ETH_HLEN 14 > - > -#define ETH_P_IP 0x0800 /* Internet Protocol packet */ > -#define ETH_P_ARP 0x0806 /* Address Resolution packet */ > - > -#define ARPOP_REQUEST 1 /* ARP request */ > -#define ARPOP_REPLY 2 /* ARP reply */ > - > -struct ethhdr > -{ > - unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ > - unsigned char h_source[ETH_ALEN]; /* source ether addr */ > - unsigned short h_proto; /* packet type ID field */ > -}; > - > -struct arphdr > -{ > - unsigned short ar_hrd; /* format of hardware address */ > - unsigned short ar_pro; /* format of protocol address */ > - unsigned char ar_hln; /* length of hardware address */ > - unsigned char ar_pln; /* length of protocol address */ > - unsigned short ar_op; /* ARP opcode (command) */ > - > - /* > - * Ethernet looks like this : This bit is variable sized however... > - */ > - unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ > - uint32_t ar_sip; /* sender IP address */ > - unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ > - uint32_t ar_tip ; /* target IP address */ > -} __attribute__((packed)); > - > static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) > { > - struct ethhdr *eh = (struct ethhdr *)pkt; > struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); > uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)]; > struct ethhdr *reh = (struct ethhdr *)arp_reply; > @@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) > ar_op = ntohs(ah->ar_op); > switch(ar_op) { > case ARPOP_REQUEST: > + if (ah->ar_tip == ah->ar_sip) { > + /* Gratuitous ARP */ > + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); > + return; > + } > + > if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) == > slirp->vnetwork_addr.s_addr) { > if (ah->ar_tip == slirp->vnameserver_addr.s_addr || > @@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) > return; > arp_ok: > memset(arp_reply, 0, sizeof(arp_reply)); > - /* XXX: make an ARP request to have the client address */ > - memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN); > + > + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); > > /* ARP request for alias/dns mac address */ > memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); > @@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) > } > break; > case ARPOP_REPLY: > - /* reply to request of client mac address ? */ > - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) && > - ah->ar_sip == slirp->client_ipaddr.s_addr) { > - memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN); > - } > + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); > break; > default: > break; > @@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) > { > uint8_t buf[1600]; > struct ethhdr *eh = (struct ethhdr *)buf; > + uint8_t ethaddr[ETH_ALEN]; > + const struct ip *iph = (const struct ip *)ip_data; > > if (ip_data_len + ETH_HLEN > sizeof(buf)) > return; > - > - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) { > + > + if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { > uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; > struct ethhdr *reh = (struct ethhdr *)arp_req; > struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); > - const struct ip *iph = (const struct ip *)ip_data; > > /* If the client addr is not known, there is no point in > sending the packet to it. Normally the sender should have > @@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) > slirp->client_ipaddr = iph->ip_dst; > slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); > } else { > - memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN); > + memcpy(eh->h_dest, ethaddr, ETH_ALEN); > memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); > /* XXX: not correct */ > memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); > diff --git a/slirp/slirp.h b/slirp/slirp.h > index 16bb6ba..2a070e6 100644 > --- a/slirp/slirp.h > +++ b/slirp/slirp.h > @@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia); > /* osdep.c */ > int qemu_socket(int domain, int type, int protocol); > > +#define ETH_ALEN 6 > +#define ETH_HLEN 14 > + > +#define ETH_P_IP 0x0800 /* Internet Protocol packet */ > +#define ETH_P_ARP 0x0806 /* Address Resolution packet */ > + > +#define ARPOP_REQUEST 1 /* ARP request */ > +#define ARPOP_REPLY 2 /* ARP reply */ > + > +struct ethhdr { > + unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ > + unsigned char h_source[ETH_ALEN]; /* source ether addr */ > + unsigned short h_proto; /* packet type ID field */ > +}; > + > +struct arphdr { > + unsigned short ar_hrd; /* format of hardware address */ > + unsigned short ar_pro; /* format of protocol address */ > + unsigned char ar_hln; /* length of hardware address */ > + unsigned char ar_pln; /* length of protocol address */ > + unsigned short ar_op; /* ARP opcode (command) */ > + > + /* > + * Ethernet looks like this : This bit is variable sized however... > + */ > + unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ > + uint32_t ar_sip; /* sender IP address */ > + unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ > + uint32_t ar_tip; /* target IP address */ > +} __attribute__((packed)); > + > +#define ARP_TABLE_SIZE 16 > + > +typedef struct ArpTable { > + struct arphdr table[ARP_TABLE_SIZE]; > + int next_victim; > +} ArpTable; > + > +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]); > + > +bool arp_table_search(Slirp *slirp, int in_ip_addr, > + uint8_t out_ethaddr[ETH_ALEN]); > > struct Slirp { > QTAILQ_ENTRY(Slirp) entry; > @@ -181,9 +223,6 @@ struct Slirp { > struct in_addr vdhcp_startaddr; > struct in_addr vnameserver_addr; > > - /* ARP cache for the guest IP addresses (XXX: allow many entries) */ > - uint8_t client_ethaddr[6]; > - > struct in_addr client_ipaddr; > char client_hostname[33]; > > @@ -227,6 +266,8 @@ struct Slirp { > char *tftp_prefix; > struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX]; > > + ArpTable arp_table; > + > void *opaque; > }; > > -- > 1.7.4.1 > Looks good now and work here as well. One last thing (I swear): We need a proper license header for arp_table.c. Then I'll apply this and v3 of 2/2 and send out a pull request (Anthony asked me to look after slirp). Thanks, Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [Qemu-devel] [PATCH V4 1/2] [SLIRP] Simple ARP table 2011-08-03 9:13 ` Jan Kiszka @ 2011-08-03 10:44 ` Fabien Chouteau 2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau 1 sibling, 0 replies; 8+ messages in thread From: Fabien Chouteau @ 2011-08-03 10:44 UTC (permalink / raw) To: Jan Kiszka; +Cc: qemu-devel@nongnu.org On 03/08/2011 11:13, Jan Kiszka wrote: > On 2011-08-02 15:19, Fabien Chouteau wrote: >> This patch adds a simple ARP table in Slirp and also adds handling of >> gratuitous ARP requests. > ... > Looks good now and work here as well. Great! > One last thing (I swear): We need a proper license header for > arp_table.c. Sure, I'll send V5 in a few minutes. > Then I'll apply this and v3 of 2/2 and send out a pull > request (Anthony asked me to look after slirp). Thanks, -- Fabien Chouteau ^ permalink raw reply [flat|nested] 8+ messages in thread
* [Qemu-devel] [PATCH V5 1/2] [SLIRP] Simple ARP table 2011-08-03 9:13 ` Jan Kiszka 2011-08-03 10:44 ` Fabien Chouteau @ 2011-08-03 10:52 ` Fabien Chouteau 1 sibling, 0 replies; 8+ messages in thread From: Fabien Chouteau @ 2011-08-03 10:52 UTC (permalink / raw) To: qemu-devel; +Cc: jan.kiszka This patch adds a simple ARP table in Slirp and also adds handling of gratuitous ARP requests. Signed-off-by: Fabien Chouteau <chouteau@adacore.com> --- Makefile.objs | 2 +- slirp/arp_table.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++ slirp/bootp.c | 21 +++++++---- slirp/slirp.c | 63 +++++++++-------------------------- slirp/slirp.h | 47 ++++++++++++++++++++++++-- 5 files changed, 169 insertions(+), 59 deletions(-) create mode 100644 slirp/arp_table.c diff --git a/Makefile.objs b/Makefile.objs index 6991a9f..0c10557 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -151,7 +151,7 @@ common-obj-y += qemu-timer.o qemu-timer-common.o slirp-obj-y = cksum.o if.o ip_icmp.o ip_input.o ip_output.o slirp-obj-y += slirp.o mbuf.o misc.o sbuf.o socket.o tcp_input.o tcp_output.o -slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o +slirp-obj-y += tcp_subr.o tcp_timer.o udp.o bootp.o tftp.o arp_table.o common-obj-$(CONFIG_SLIRP) += $(addprefix slirp/, $(slirp-obj-y)) # xen backend driver support diff --git a/slirp/arp_table.c b/slirp/arp_table.c new file mode 100644 index 0000000..820dee2 --- /dev/null +++ b/slirp/arp_table.c @@ -0,0 +1,95 @@ +/* + * ARP table + * + * Copyright (c) 2011 AdaCore + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include "slirp.h" + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_add"); + DEBUG_ARG("ip = 0x%x", ip_addr); + DEBUG_ARGS((dfd, " hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + ethaddr[0], ethaddr[1], ethaddr[2], + ethaddr[3], ethaddr[4], ethaddr[5])); + + /* Check 0.0.0.0/8 invalid source-only addresses */ + assert((ip_addr & htonl(~(0xf << 28))) != 0); + + if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) { + /* Do not register broadcast addresses */ + return; + } + + /* Search for an entry */ + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if (arptbl->table[i].ar_sip == ip_addr) { + /* Update the entry */ + memcpy(arptbl->table[i].ar_sha, ethaddr, ETH_ALEN); + return; + } + } + + /* No entry found, create a new one */ + arptbl->table[arptbl->next_victim].ar_sip = ip_addr; + memcpy(arptbl->table[arptbl->next_victim].ar_sha, ethaddr, ETH_ALEN); + arptbl->next_victim = (arptbl->next_victim + 1) % ARP_TABLE_SIZE; +} + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]) +{ + const in_addr_t broadcast_addr = + ~slirp->vnetwork_mask.s_addr | slirp->vnetwork_addr.s_addr; + ArpTable *arptbl = &slirp->arp_table; + int i; + + DEBUG_CALL("arp_table_search"); + DEBUG_ARG("ip = 0x%x", in_ip_addr); + + /* Check 0.0.0.0/8 invalid source-only addresses */ + assert((in_ip_addr & htonl(~(0xf << 28))) != 0); + + /* If broadcast address */ + if (in_ip_addr == 0xffffffff || in_ip_addr == broadcast_addr) { + /* return Ethernet broadcast address */ + memset(out_ethaddr, 0xff, ETH_ALEN); + return 1; + } + + for (i = 0; i < ARP_TABLE_SIZE; i++) { + if (arptbl->table[i].ar_sip == in_ip_addr) { + memcpy(out_ethaddr, arptbl->table[i].ar_sha, ETH_ALEN); + DEBUG_ARGS((dfd, " found hw addr = %02x:%02x:%02x:%02x:%02x:%02x\n", + out_ethaddr[0], out_ethaddr[1], out_ethaddr[2], + out_ethaddr[3], out_ethaddr[4], out_ethaddr[5])); + return 1; + } + } + + return 0; +} diff --git a/slirp/bootp.c b/slirp/bootp.c index 1eb2ed1..efd1fe7 100644 --- a/slirp/bootp.c +++ b/slirp/bootp.c @@ -149,6 +149,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) struct in_addr preq_addr; int dhcp_msg_type, val; uint8_t *q; + uint8_t client_ethaddr[ETH_ALEN]; /* extract exact DHCP msg type */ dhcp_decode(bp, &dhcp_msg_type, &preq_addr); @@ -164,8 +165,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type != DHCPDISCOVER && dhcp_msg_type != DHCPREQUEST) return; - /* XXX: this is a hack to get the client mac address */ - memcpy(slirp->client_ethaddr, bp->bp_hwaddr, 6); + + /* Get client's hardware address from bootp request */ + memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN); m = m_get(slirp); if (!m) { @@ -178,25 +180,25 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) if (dhcp_msg_type == DHCPDISCOVER) { if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; } } if (!bc) { new_addr: - bc = get_new_addr(slirp, &daddr.sin_addr, slirp->client_ethaddr); + bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr); if (!bc) { DPRINTF("no address left\n"); return; } } - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else if (preq_addr.s_addr != htonl(0L)) { - bc = request_addr(slirp, &preq_addr, slirp->client_ethaddr); + bc = request_addr(slirp, &preq_addr, client_ethaddr); if (bc) { daddr.sin_addr = preq_addr; - memcpy(bc->macaddr, slirp->client_ethaddr, 6); + memcpy(bc->macaddr, client_ethaddr, ETH_ALEN); } else { daddr.sin_addr.s_addr = 0; } @@ -209,6 +211,9 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) } } + /* Update ARP table for this IP address */ + arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr); + saddr.sin_addr = slirp->vhost_addr; saddr.sin_port = htons(BOOTP_SERVER); @@ -218,7 +223,7 @@ static void bootp_reply(Slirp *slirp, const struct bootp_t *bp) rbp->bp_xid = bp->bp_xid; rbp->bp_htype = 1; rbp->bp_hlen = 6; - memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6); + memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN); rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */ rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */ diff --git a/slirp/slirp.c b/slirp/slirp.c index df787ea..4a9a4d5 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -31,11 +31,11 @@ struct in_addr loopback_addr; /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */ -static const uint8_t special_ethaddr[6] = { +static const uint8_t special_ethaddr[ETH_ALEN] = { 0x52, 0x55, 0x00, 0x00, 0x00, 0x00 }; -static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 }; +static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 }; /* XXX: suppress those select globals */ fd_set *global_readfds, *global_writefds, *global_xfds; @@ -599,42 +599,8 @@ void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds, global_xfds = NULL; } -#define ETH_ALEN 6 -#define ETH_HLEN 14 - -#define ETH_P_IP 0x0800 /* Internet Protocol packet */ -#define ETH_P_ARP 0x0806 /* Address Resolution packet */ - -#define ARPOP_REQUEST 1 /* ARP request */ -#define ARPOP_REPLY 2 /* ARP reply */ - -struct ethhdr -{ - unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ - unsigned char h_source[ETH_ALEN]; /* source ether addr */ - unsigned short h_proto; /* packet type ID field */ -}; - -struct arphdr -{ - unsigned short ar_hrd; /* format of hardware address */ - unsigned short ar_pro; /* format of protocol address */ - unsigned char ar_hln; /* length of hardware address */ - unsigned char ar_pln; /* length of protocol address */ - unsigned short ar_op; /* ARP opcode (command) */ - - /* - * Ethernet looks like this : This bit is variable sized however... - */ - unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ - uint32_t ar_sip; /* sender IP address */ - unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ - uint32_t ar_tip ; /* target IP address */ -} __attribute__((packed)); - static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) { - struct ethhdr *eh = (struct ethhdr *)pkt; struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)]; struct ethhdr *reh = (struct ethhdr *)arp_reply; @@ -645,6 +611,12 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) ar_op = ntohs(ah->ar_op); switch(ar_op) { case ARPOP_REQUEST: + if (ah->ar_tip == ah->ar_sip) { + /* Gratuitous ARP */ + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); + return; + } + if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { if (ah->ar_tip == slirp->vnameserver_addr.s_addr || @@ -657,8 +629,8 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) return; arp_ok: memset(arp_reply, 0, sizeof(arp_reply)); - /* XXX: make an ARP request to have the client address */ - memcpy(slirp->client_ethaddr, eh->h_source, ETH_ALEN); + + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); /* ARP request for alias/dns mac address */ memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); @@ -679,11 +651,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len) } break; case ARPOP_REPLY: - /* reply to request of client mac address ? */ - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN) && - ah->ar_sip == slirp->client_ipaddr.s_addr) { - memcpy(slirp->client_ethaddr, ah->ar_sha, ETH_ALEN); - } + arp_table_add(slirp, ah->ar_sip, ah->ar_sha); break; default: break; @@ -729,15 +697,16 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) { uint8_t buf[1600]; struct ethhdr *eh = (struct ethhdr *)buf; + uint8_t ethaddr[ETH_ALEN]; + const struct ip *iph = (const struct ip *)ip_data; if (ip_data_len + ETH_HLEN > sizeof(buf)) return; - - if (!memcmp(slirp->client_ethaddr, zero_ethaddr, ETH_ALEN)) { + + if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) { uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)]; struct ethhdr *reh = (struct ethhdr *)arp_req; struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN); - const struct ip *iph = (const struct ip *)ip_data; /* If the client addr is not known, there is no point in sending the packet to it. Normally the sender should have @@ -765,7 +734,7 @@ void if_encap(Slirp *slirp, const uint8_t *ip_data, int ip_data_len) slirp->client_ipaddr = iph->ip_dst; slirp_output(slirp->opaque, arp_req, sizeof(arp_req)); } else { - memcpy(eh->h_dest, slirp->client_ethaddr, ETH_ALEN); + memcpy(eh->h_dest, ethaddr, ETH_ALEN); memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4); /* XXX: not correct */ memcpy(&eh->h_source[2], &slirp->vhost_addr, 4); diff --git a/slirp/slirp.h b/slirp/slirp.h index 16bb6ba..2a070e6 100644 --- a/slirp/slirp.h +++ b/slirp/slirp.h @@ -170,6 +170,48 @@ int inet_aton(const char *cp, struct in_addr *ia); /* osdep.c */ int qemu_socket(int domain, int type, int protocol); +#define ETH_ALEN 6 +#define ETH_HLEN 14 + +#define ETH_P_IP 0x0800 /* Internet Protocol packet */ +#define ETH_P_ARP 0x0806 /* Address Resolution packet */ + +#define ARPOP_REQUEST 1 /* ARP request */ +#define ARPOP_REPLY 2 /* ARP reply */ + +struct ethhdr { + unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ + unsigned char h_source[ETH_ALEN]; /* source ether addr */ + unsigned short h_proto; /* packet type ID field */ +}; + +struct arphdr { + unsigned short ar_hrd; /* format of hardware address */ + unsigned short ar_pro; /* format of protocol address */ + unsigned char ar_hln; /* length of hardware address */ + unsigned char ar_pln; /* length of protocol address */ + unsigned short ar_op; /* ARP opcode (command) */ + + /* + * Ethernet looks like this : This bit is variable sized however... + */ + unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ + uint32_t ar_sip; /* sender IP address */ + unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ + uint32_t ar_tip; /* target IP address */ +} __attribute__((packed)); + +#define ARP_TABLE_SIZE 16 + +typedef struct ArpTable { + struct arphdr table[ARP_TABLE_SIZE]; + int next_victim; +} ArpTable; + +void arp_table_add(Slirp *slirp, int ip_addr, uint8_t ethaddr[ETH_ALEN]); + +bool arp_table_search(Slirp *slirp, int in_ip_addr, + uint8_t out_ethaddr[ETH_ALEN]); struct Slirp { QTAILQ_ENTRY(Slirp) entry; @@ -181,9 +223,6 @@ struct Slirp { struct in_addr vdhcp_startaddr; struct in_addr vnameserver_addr; - /* ARP cache for the guest IP addresses (XXX: allow many entries) */ - uint8_t client_ethaddr[6]; - struct in_addr client_ipaddr; char client_hostname[33]; @@ -227,6 +266,8 @@ struct Slirp { char *tftp_prefix; struct tftp_session tftp_sessions[TFTP_SESSIONS_MAX]; + ArpTable arp_table; + void *opaque; }; -- 1.7.4.1 ^ permalink raw reply related [flat|nested] 8+ messages in thread
end of thread, other threads:[~2011-08-03 10:53 UTC | newest] Thread overview: 8+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2011-08-01 16:18 [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Fabien Chouteau 2011-08-01 16:18 ` [Qemu-devel] [PATCH V3 2/2] [SLIRP] Delayed IP packets Fabien Chouteau 2011-08-01 20:16 ` [Qemu-devel] [PATCH V3 1/2] [SLIRP] Simple ARP table Jan Kiszka 2011-08-02 9:58 ` Fabien Chouteau 2011-08-02 13:19 ` [Qemu-devel] [PATCH V4 " Fabien Chouteau 2011-08-03 9:13 ` Jan Kiszka 2011-08-03 10:44 ` Fabien Chouteau 2011-08-03 10:52 ` [Qemu-devel] [PATCH V5 " Fabien Chouteau
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