/* $NetBSD: nfs_bootdhcp.c,v 1.13 2000/01/20 08:34:52 enami Exp $ */ /*- * Copyright (c) 1995, 1997 The NetBSD Foundation, Inc. * All rights reserved. * * This code is derived from software contributed to The NetBSD Foundation * by Adam Glass and Gordon W. Ross. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the NetBSD * Foundation, Inc. and its contributors. * 4. Neither the name of The NetBSD Foundation nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ /* * Support for NFS diskless booting with BOOTP (RFC951, RFC1048) * * History: * * Tor Egge developed the initial version of this code based on * the Sun RPC/bootparam sources nfs_boot.c and krpc_subr.c and * submitted that work to NetBSD as bugreport "kern/2351" on * 29 Apr 1996. * * Gordon Ross reorganized Tor's version into this form and * integrated it into the NetBSD sources during Aug 1997. */ #include "opt_nfs_boot.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* ARPHRD_ETHER, etc. */ #include #include #include #include #include #include #include #include #include #include /* * There are two implementations of NFS diskless boot. * This implementation uses BOOTP (RFC951, RFC1048), and * the other uses Sun RPC/bootparams (nfs_bootparam.c). * * This method gets everything it needs with one BOOTP * request and reply. Note that this actually uses only * the old BOOTP functionality subset of DHCP. It is not * clear that DHCP provides any advantage over BOOTP for * diskless boot. DHCP allows the server to assign an IP * address without any a-priori knowledge of the client, * but we require that the server has a-priori knowledge * of the client so it can export our (unique) NFS root. * Given that the server needs a-priori knowledge about * the client anyway, it might as well assign a fixed IP * address for the client and support BOOTP. * * On the other hand, disk-FULL clients may use DHCP, but * in that case the DHCP client should be user-mode code, * and has no bearing on the code below. -gwr */ /* Begin stuff from bootp.h */ /* Definitions from RFC951 */ #define BP_CHADDR_LEN 16 #define BP_SNAME_LEN 64 #define BP_FILE_LEN 128 #define BP_VEND_LEN 64 struct bootp { u_int8_t bp_op; /* packet opcode type */ u_int8_t bp_htype; /* hardware addr type */ u_int8_t bp_hlen; /* hardware addr length */ u_int8_t bp_hops; /* gateway hops */ u_int32_t bp_xid; /* transaction ID */ u_int16_t bp_secs; /* seconds since boot began */ u_int16_t bp_flags; /* RFC1532 broadcast, etc. */ struct in_addr bp_ciaddr; /* client IP address */ struct in_addr bp_yiaddr; /* 'your' IP address */ struct in_addr bp_siaddr; /* server IP address */ struct in_addr bp_giaddr; /* gateway IP address */ u_int8_t bp_chaddr[BP_CHADDR_LEN]; /* client hardware address */ char bp_sname[BP_SNAME_LEN]; /* server host name */ char bp_file[BP_FILE_LEN]; /* boot file name */ u_int8_t bp_vend[BP_VEND_LEN]; /* RFC1048 options */ /* * Note that BOOTP packets are allowed to be longer * (see RFC 1532 sect. 2.1) and common practice is to * allow the option data in bp_vend to extend into the * additional space provided in longer packets. */ }; #define IPPORT_BOOTPS 67 #define IPPORT_BOOTPC 68 #define BOOTREQUEST 1 #define BOOTREPLY 2 /* * Is this available from the sockaddr_dl somehow? * Perhaps (struct arphdr)->ar_hrd = ARPHRD_ETHER? * The interface has ->if_type but not the ARP fmt. */ #define HTYPE_ETHERNET 1 /* * Vendor magic cookie (v_magic) for RFC1048 */ static const u_int8_t vm_rfc1048[4] = { 99, 130, 83, 99 }; /* * Tag values used to specify what information is being supplied in * the vendor (options) data area of the packet. */ /* RFC 1048 */ #define TAG_END ((unsigned char) 255) #define TAG_PAD ((unsigned char) 0) #define TAG_SUBNET_MASK ((unsigned char) 1) #define TAG_TIME_OFFSET ((unsigned char) 2) #define TAG_GATEWAY ((unsigned char) 3) #define TAG_TIME_SERVER ((unsigned char) 4) #define TAG_NAME_SERVER ((unsigned char) 5) #define TAG_DOMAIN_SERVER ((unsigned char) 6) #define TAG_LOG_SERVER ((unsigned char) 7) #define TAG_COOKIE_SERVER ((unsigned char) 8) #define TAG_LPR_SERVER ((unsigned char) 9) #define TAG_IMPRESS_SERVER ((unsigned char) 10) #define TAG_RLP_SERVER ((unsigned char) 11) #define TAG_HOST_NAME ((unsigned char) 12) #define TAG_BOOT_SIZE ((unsigned char) 13) /* RFC 1395 */ #define TAG_DUMP_FILE ((unsigned char) 14) #define TAG_DOMAIN_NAME ((unsigned char) 15) #define TAG_SWAP_SERVER ((unsigned char) 16) #define TAG_ROOT_PATH ((unsigned char) 17) /* End of stuff from bootp.h */ #ifdef NFS_BOOT_DHCP #define TAG_REQ_ADDR ((unsigned char) 50) #define TAG_LEASETIME ((unsigned char) 51) #define TAG_OVERLOAD ((unsigned char) 52) #define TAG_DHCP_MSGTYPE ((unsigned char) 53) #define TAG_SERVERID ((unsigned char) 54) #define TAG_PARAM_REQ ((unsigned char) 55) #define TAG_MSG ((unsigned char) 56) #define TAG_MAXSIZE ((unsigned char) 57) #define TAG_T1 ((unsigned char) 58) #define TAG_T2 ((unsigned char) 59) #define TAG_CLASSID ((unsigned char) 60) #define TAG_CLIENTID ((unsigned char) 61) #endif #ifdef NFS_BOOT_DHCP #define DHCPDISCOVER 1 #define DHCPOFFER 2 #define DHCPREQUEST 3 #define DHCPDECLINE 4 #define DHCPACK 5 #define DHCPNAK 6 #define DHCPRELEASE 7 #endif #ifdef NFS_BOOT_DHCP #define BOOTP_SIZE_MAX (sizeof(struct bootp)+312-64) #else /* * The "extended" size is somewhat arbitrary, but is * constrained by the maximum message size specified * by RFC1533 (567 total). This value increases the * space for options from 64 bytes to 256 bytes. */ #define BOOTP_SIZE_MAX (sizeof(struct bootp)+256-64) #endif #define BOOTP_SIZE_MIN (sizeof(struct bootp)) /* Convenience macro */ #define INTOHL(ina) ((u_int32_t)ntohl((ina).s_addr)) static int bootpc_call __P((struct nfs_diskless *, struct proc *)); static void bootp_extract __P((struct bootp *, int, struct nfs_diskless *)); /* #define DEBUG XXX */ #ifdef DEBUG #define DPRINT(s) printf("nfs_boot: %s\n", s) #else #define DPRINT(s) (void)0 #endif /* * Get our boot parameters using BOOTP. */ int nfs_bootdhcp(nd, procp) struct nfs_diskless *nd; struct proc *procp; { struct ifnet *ifp = nd->nd_ifp; int error; /* * Do enough of ifconfig(8) so that the chosen interface * can talk to the servers. Use address zero for now. */ error = nfs_boot_setaddress(ifp, procp, INADDR_ANY, INADDR_ANY, INADDR_BROADCAST); if (error) { printf("nfs_boot: set ifaddr zero, error=%d\n", error); return (error); } /* This function call does the real send/recv work. */ error = bootpc_call(nd, procp); /* Get rid of the temporary (zero) IP address. */ (void) nfs_boot_deladdress(ifp, procp, INADDR_ANY); /* NOW we can test the error from bootpc_call. */ if (error) goto out; /* * Do ifconfig with our real IP address and mask. */ error = nfs_boot_setaddress(ifp, procp, nd->nd_myip.s_addr, nd->nd_mask.s_addr, INADDR_ANY); if (error) { printf("nfs_boot: set ifaddr real, error=%d\n", error); goto out; } out: if (error) { (void) nfs_boot_ifupdown(ifp, procp, 0); nfs_boot_flushrt(ifp); } return (error); } struct bootpcontext { int xid; u_char *haddr; u_char halen; struct bootp *replybuf; int replylen; #ifdef NFS_BOOT_DHCP char expected_dhcpmsgtype, dhcp_ok; struct in_addr dhcp_serverip; #endif }; static int bootpset __P((struct mbuf*, void*, int)); static int bootpcheck __P((struct mbuf*, void*)); static int bootpset(m, context, waited) struct mbuf *m; void *context; int waited; { struct bootp *bootp; /* we know it's contigous (in 1 mbuf cluster) */ bootp = mtod(m, struct bootp*); bootp->bp_secs = htons(waited); return (0); } static int bootpcheck(m, context) struct mbuf *m; void *context; { struct bootp *bootp; struct bootpcontext *bpc = context; u_int tag, len; u_char *p, *limit; /* * Is this a valid reply? */ if (m->m_pkthdr.len < BOOTP_SIZE_MIN) { DPRINT("short packet"); return (-1); } if (m->m_pkthdr.len > BOOTP_SIZE_MAX) { DPRINT("long packet"); return (-1); } /* * don't make first checks more expensive than necessary */ #define ofs(what, elem) ((int)&(((what *)0)->elem)) if (m->m_len < ofs(struct bootp, bp_secs)) { m = m_pullup(m, ofs(struct bootp, bp_secs)); if (m == NULL) return (-1); } #undef ofs bootp = mtod(m, struct bootp*); if (bootp->bp_op != BOOTREPLY) { DPRINT("not reply"); return (-1); } if (bootp->bp_hlen != bpc->halen) { DPRINT("bad hwa_len"); return (-1); } if (memcmp(bootp->bp_chaddr, bpc->haddr, bpc->halen)) { DPRINT("wrong hwaddr"); return (-1); } if (bootp->bp_xid != bpc->xid) { DPRINT("wrong xid"); return (-1); } /* * OK, it's worth to look deeper. * We copy the mbuf into a flat buffer here because * m_pullup() is a bit limited for this purpose * (doesn't allocate a cluster if necessary). */ bpc->replylen = m->m_pkthdr.len; m_copydata(m, 0, bpc->replylen, (caddr_t)bpc->replybuf); bootp = bpc->replybuf; /* * Check if the IP address we get looks correct. * (DHCP servers can send junk to unknown clients.) * XXX more checks might be needed */ if (bootp->bp_yiaddr.s_addr == INADDR_ANY || bootp->bp_yiaddr.s_addr == INADDR_BROADCAST) { printf("nfs_boot: wrong IP addr %s", inet_ntoa(bootp->bp_yiaddr)); goto warn; } /* * Check the vendor data. */ if (memcmp(bootp->bp_vend, vm_rfc1048, 4)) { printf("nfs_boot: reply missing options"); goto warn; } p = &bootp->bp_vend[4]; limit = ((char*)bootp) + bpc->replylen; while (p < limit) { tag = *p++; if (tag == TAG_END) break; if (tag == TAG_PAD) continue; len = *p++; if ((p + len) > limit) { printf("nfs_boot: option %d too long", tag); goto warn; } switch (tag) { #ifdef NFS_BOOT_DHCP case TAG_DHCP_MSGTYPE: if (*p != bpc->expected_dhcpmsgtype) return (-1); bpc->dhcp_ok = 1; break; case TAG_SERVERID: memcpy(&bpc->dhcp_serverip.s_addr, p, sizeof(bpc->dhcp_serverip.s_addr)); break; #endif default: break; } p += len; } return (0); warn: printf(" (bad reply from %s)\n", inet_ntoa(bootp->bp_siaddr)); return (-1); } static int bootpc_call(nd, procp) struct nfs_diskless *nd; struct proc *procp; { struct socket *so; struct ifnet *ifp = nd->nd_ifp; static u_int32_t xid = ~0xFF; struct bootp *bootp; /* request */ struct mbuf *m, *nam; struct sockaddr_in *sin; int error; u_char *haddr; u_char hafmt, halen; struct bootpcontext bpc; error = socreate(AF_INET, &so, SOCK_DGRAM, 0); if (error) { printf("bootp: socreate, error=%d\n", error); return (error); } /* * Initialize to NULL anything that will hold an allocation, * and free each at the end if not null. */ bpc.replybuf = NULL; m = nam = NULL; /* Record our H/W (Ethernet) address. */ { struct sockaddr_dl *sdl = ifp->if_sadl; switch (sdl->sdl_type) { case IFT_ETHER: case IFT_FDDI: hafmt = HTYPE_ETHERNET; break; default: printf("bootp: unsupported interface type %d\n", sdl->sdl_type); error = EINVAL; goto out; } halen = sdl->sdl_alen; haddr = (unsigned char *)LLADDR(sdl); } /* * Skip the route table when sending on this socket. * If this is not done, ip_output finds the loopback * interface (why?) and then fails because broadcast * is not supported on that interface... */ { int32_t *opt; m = m_get(M_WAIT, MT_SOOPTS); opt = mtod(m, int32_t *); m->m_len = sizeof(*opt); *opt = 1; error = sosetopt(so, SOL_SOCKET, SO_DONTROUTE, m); m = NULL; /* was consumed */ } if (error) { DPRINT("SO_DONTROUTE"); goto out; } /* Enable broadcast. */ if ((error = nfs_boot_enbroadcast(so))) { DPRINT("SO_BROADCAST"); goto out; } /* Set the receive timeout for the socket. */ if ((error = nfs_boot_setrecvtimo(so))) { DPRINT("SO_RCVTIMEO"); goto out; } /* * Bind the local endpoint to a bootp client port. */ if ((error = nfs_boot_sobind_ipport(so, IPPORT_BOOTPC))) { DPRINT("bind failed\n"); goto out; } /* * Setup socket address for the server. */ nam = m_get(M_WAIT, MT_SONAME); sin = mtod(nam, struct sockaddr_in *); sin->sin_len = nam->m_len = sizeof(*sin); sin->sin_family = AF_INET; sin->sin_addr.s_addr = INADDR_BROADCAST; sin->sin_port = htons(IPPORT_BOOTPS); /* * Allocate buffer used for request */ m = m_gethdr(M_WAIT, MT_DATA); MCLGET(m, M_WAIT); bootp = mtod(m, struct bootp*); m->m_pkthdr.len = m->m_len = BOOTP_SIZE_MAX; m->m_pkthdr.rcvif = NULL; /* * Build the BOOTP reqest message. * Note: xid is host order! (opaque to server) */ memset((caddr_t)bootp, 0, BOOTP_SIZE_MAX); bootp->bp_op = BOOTREQUEST; bootp->bp_htype = hafmt; bootp->bp_hlen = halen; /* Hardware address length */ bootp->bp_xid = ++xid; memcpy(bootp->bp_chaddr, haddr, halen); /* Fill-in the vendor data. */ memcpy(bootp->bp_vend, vm_rfc1048, 4); #ifdef NFS_BOOT_DHCP bootp->bp_vend[4] = TAG_DHCP_MSGTYPE; bootp->bp_vend[5] = 1; bootp->bp_vend[6] = DHCPDISCOVER; bootp->bp_vend[7] = TAG_END; #else bootp->bp_vend[4] = TAG_END; #endif bpc.xid = xid; bpc.haddr = haddr; bpc.halen = halen; bpc.replybuf = malloc(BOOTP_SIZE_MAX, M_DEVBUF, M_WAITOK); if (bpc.replybuf == NULL) panic("nfs_boot: malloc reply buf"); #ifdef NFS_BOOT_DHCP bpc.expected_dhcpmsgtype = DHCPOFFER; bpc.dhcp_ok = 0; #endif error = nfs_boot_sendrecv(so, nam, bootpset, m, bootpcheck, 0, 0, &bpc); if (error) goto out; #ifdef NFS_BOOT_DHCP if (bpc.dhcp_ok) { u_int32_t leasetime; bootp->bp_vend[6] = DHCPREQUEST; bootp->bp_vend[7] = TAG_REQ_ADDR; bootp->bp_vend[8] = 4; memcpy(&bootp->bp_vend[9], &bpc.replybuf->bp_yiaddr, 4); bootp->bp_vend[13] = TAG_SERVERID; bootp->bp_vend[14] = 4; memcpy(&bootp->bp_vend[15], &bpc.dhcp_serverip.s_addr, 4); bootp->bp_vend[19] = TAG_LEASETIME; bootp->bp_vend[20] = 4; leasetime = htonl(300); memcpy(&bootp->bp_vend[21], &leasetime, 4); bootp->bp_vend[25] = TAG_END; bpc.expected_dhcpmsgtype = DHCPACK; error = nfs_boot_sendrecv(so, nam, bootpset, m, bootpcheck, 0, 0, &bpc); if (error) goto out; } #endif /* * bootpcheck() has copied the receive mbuf into * the buffer at bpc.replybuf. */ #ifdef NFS_BOOT_DHCP printf("nfs_boot: %s server: %s\n", (bpc.dhcp_ok ? "DHCP" : "BOOTP"), #else printf("nfs_boot: BOOTP server: %s\n", #endif inet_ntoa(bpc.replybuf->bp_siaddr)); bootp_extract(bpc.replybuf, bpc.replylen, nd); out: if (bpc.replybuf) free(bpc.replybuf, M_DEVBUF); if (m) m_freem(m); if (nam) m_freem(nam); soclose(so); return (error); } static void bootp_extract(bootp, replylen, nd) struct bootp *bootp; int replylen; struct nfs_diskless *nd; { struct sockaddr_in *sin; struct in_addr netmask; struct in_addr gateway; struct in_addr rootserver; char *myname; /* my hostname */ char *mydomain; /* my domainname */ char *rootpath; int mynamelen; int mydomainlen; int rootpathlen; int overloaded; u_int tag, len; u_char *p, *limit; /* Default these to "unspecified". */ netmask.s_addr = 0; gateway.s_addr = 0; mydomain = myname = rootpath = NULL; mydomainlen = mynamelen = rootpathlen = 0; /* default root server to bootp next-server */ rootserver = bootp->bp_siaddr; /* assume that server name field is not overloaded by default */ overloaded = 0; p = &bootp->bp_vend[4]; limit = ((char*)bootp) + replylen; while (p < limit) { tag = *p++; if (tag == TAG_END) break; if (tag == TAG_PAD) continue; len = *p++; #if 0 /* already done in bootpcheck() */ if ((p + len) > limit) { printf("nfs_boot: option %d too long\n", tag); break; } #endif switch (tag) { case TAG_SUBNET_MASK: memcpy(&netmask, p, 4); break; case TAG_GATEWAY: /* Routers */ memcpy(&gateway, p, 4); break; case TAG_HOST_NAME: if (len >= sizeof(hostname)) { printf("nfs_boot: host name >= %lu bytes", (u_long)sizeof(hostname)); break; } myname = p; mynamelen = len; break; case TAG_DOMAIN_NAME: if (len >= sizeof(domainname)) { printf("nfs_boot: domain name >= %lu bytes", (u_long)sizeof(domainname)); break; } mydomain = p; mydomainlen = len; break; case TAG_ROOT_PATH: /* Leave some room for the server name. */ if (len >= (MNAMELEN-10)) { printf("nfs_boot: rootpath >=%d bytes", (MNAMELEN-10)); break; } rootpath = p; rootpathlen = len; break; case TAG_SWAP_SERVER: /* override NFS server address */ memcpy(&rootserver, p, 4); break; #ifdef NFS_BOOT_DHCP case TAG_OVERLOAD: if (len > 0 && ((*p & 0x02) != 0)) /* * The server name field in the dhcp packet * is overloaded and we can't find server * name there. */ overloaded = 1; break; #endif default: break; } p += len; } /* * Store and print network config info. */ if (myname) { myname[mynamelen] = '\0'; strncpy(hostname, myname, sizeof(hostname)); hostnamelen = mynamelen; printf("nfs_boot: my_name=%s\n", hostname); } if (mydomain) { mydomain[mydomainlen] = '\0'; strncpy(domainname, mydomain, sizeof(domainname)); domainnamelen = mydomainlen; printf("nfs_boot: my_domain=%s\n", domainname); } nd->nd_myip = bootp->bp_yiaddr; if (nd->nd_myip.s_addr) printf("nfs_boot: my_addr=%s\n", inet_ntoa(nd->nd_myip)); nd->nd_mask = netmask; if (nd->nd_mask.s_addr) printf("nfs_boot: my_mask=%s\n", inet_ntoa(nd->nd_mask)); nd->nd_gwip = gateway; if (nd->nd_gwip.s_addr) printf("nfs_boot: gateway=%s\n", inet_ntoa(nd->nd_gwip)); /* * Store the information about our NFS root mount. * The caller will print it, so be silent here. */ { struct nfs_dlmount *ndm = &nd->nd_root; /* Server IP address. */ sin = (struct sockaddr_in *) &ndm->ndm_saddr; memset((caddr_t)sin, 0, sizeof(*sin)); sin->sin_len = sizeof(*sin); sin->sin_family = AF_INET; sin->sin_addr = rootserver; /* Server name. */ if (!overloaded && bootp->bp_sname[0] != 0 && !memcmp(&rootserver, &bootp->bp_siaddr, sizeof(struct in_addr))) { /* standard root server, we have the name */ strncpy(ndm->ndm_host, bootp->bp_sname, BP_SNAME_LEN-1); } else { /* Show the server IP address numerically. */ strncpy(ndm->ndm_host, inet_ntoa(rootserver), BP_SNAME_LEN-1); } len = strlen(ndm->ndm_host); if (rootpath && len + 1 + rootpathlen + 1 <= sizeof(ndm->ndm_host)) { ndm->ndm_host[len++] = ':'; strncpy(ndm->ndm_host + len, rootpath, rootpathlen); ndm->ndm_host[len + rootpathlen] = '\0'; } /* else: upper layer will handle error */ } }