/* * linux/fs/nfs/callback.c * * Copyright (C) 2004 Trond Myklebust * * NFSv4 callback handling */ #include <linux/config.h> #include <linux/completion.h> #include <linux/ip.h> #include <linux/module.h> #include <linux/smp_lock.h> #include <linux/sunrpc/svc.h> #include <linux/sunrpc/svcsock.h> #include <linux/nfs_fs.h> #include "callback.h" #define NFSDBG_FACILITY NFSDBG_CALLBACK struct nfs_callback_data { unsigned int users; struct svc_serv *serv; pid_t pid; struct completion started; struct completion stopped; }; static struct nfs_callback_data nfs_callback_info; static DECLARE_MUTEX(nfs_callback_sema); static struct svc_program nfs4_callback_program; unsigned short nfs_callback_tcpport; /* * This is the callback kernel thread. */ static void nfs_callback_svc(struct svc_rqst *rqstp) { struct svc_serv *serv = rqstp->rq_server; int err; __module_get(THIS_MODULE); lock_kernel(); nfs_callback_info.pid = current->pid; daemonize("nfsv4-svc"); /* Process request with signals blocked, but allow SIGKILL. */ allow_signal(SIGKILL); complete(&nfs_callback_info.started); while (nfs_callback_info.users != 0 || !signalled()) { /* * Listen for a request on the socket */ err = svc_recv(serv, rqstp, MAX_SCHEDULE_TIMEOUT); if (err == -EAGAIN || err == -EINTR) continue; if (err < 0) { printk(KERN_WARNING "%s: terminating on error %d\n", __FUNCTION__, -err); break; } dprintk("%s: request from %u.%u.%u.%u\n", __FUNCTION__, NIPQUAD(rqstp->rq_addr.sin_addr.s_addr)); svc_process(serv, rqstp); } nfs_callback_info.pid = 0; complete(&nfs_callback_info.stopped); unlock_kernel(); module_put_and_exit(0); } /* * Bring up the server process if it is not already up. */ int nfs_callback_up(void) { struct svc_serv *serv; struct svc_sock *svsk; int ret = 0; lock_kernel(); down(&nfs_callback_sema); if (nfs_callback_info.users++ || nfs_callback_info.pid != 0) goto out; init_completion(&nfs_callback_info.started); init_completion(&nfs_callback_info.stopped); serv = svc_create(&nfs4_callback_program, NFS4_CALLBACK_BUFSIZE); ret = -ENOMEM; if (!serv) goto out_err; /* FIXME: We don't want to register this socket with the portmapper */ ret = svc_makesock(serv, IPPROTO_TCP, 0); if (ret < 0) goto out_destroy; if (!list_empty(&serv->sv_permsocks)) { svsk = list_entry(serv->sv_permsocks.next, struct svc_sock, sk_list); nfs_callback_tcpport = ntohs(inet_sk(svsk->sk_sk)->sport); dprintk ("Callback port = 0x%x\n", nfs_callback_tcpport); } else BUG(); ret = svc_create_thread(nfs_callback_svc, serv); if (ret < 0) goto out_destroy; nfs_callback_info.serv = serv; wait_for_completion(&nfs_callback_info.started); out: up(&nfs_callback_sema); unlock_kernel(); return ret; out_destroy: svc_destroy(serv); out_err: nfs_callback_info.users--; goto out; } /* * Kill the server process if it is not already up. */ int nfs_callback_down(void) { int ret = 0; lock_kernel(); down(&nfs_callback_sema); if (--nfs_callback_info.users || nfs_callback_info.pid == 0) goto out; kill_proc(nfs_callback_info.pid, SIGKILL, 1); wait_for_completion(&nfs_callback_info.stopped); out: up(&nfs_callback_sema); unlock_kernel(); return ret; } static int nfs_callback_authenticate(struct svc_rqst *rqstp) { struct in_addr *addr = &rqstp->rq_addr.sin_addr; struct nfs4_client *clp; /* Don't talk to strangers */ clp = nfs4_find_client(addr); if (clp == NULL) return SVC_DROP; dprintk("%s: %u.%u.%u.%u NFSv4 callback!\n", __FUNCTION__, NIPQUAD(addr)); nfs4_put_client(clp); switch (rqstp->rq_authop->flavour) { case RPC_AUTH_NULL: if (rqstp->rq_proc != CB_NULL) return SVC_DENIED; break; case RPC_AUTH_UNIX: break; case RPC_AUTH_GSS: /* FIXME: RPCSEC_GSS handling? */ default: return SVC_DENIED; } return SVC_OK; } /* * Define NFS4 callback program */ extern struct svc_version nfs4_callback_version1; static struct svc_version *nfs4_callback_version[] = { [1] = &nfs4_callback_version1, }; static struct svc_stat nfs4_callback_stats; static struct svc_program nfs4_callback_program = { .pg_prog = NFS4_CALLBACK, /* RPC service number */ .pg_nvers = ARRAY_SIZE(nfs4_callback_version), /* Number of entries */ .pg_vers = nfs4_callback_version, /* version table */ .pg_name = "NFSv4 callback", /* service name */ .pg_class = "nfs", /* authentication class */ .pg_stats = &nfs4_callback_stats, .pg_authenticate = nfs_callback_authenticate, };