From 77193c050850e2e80afae1dd8279342324aea9b7 Mon Sep 17 00:00:00 2001 From: Rick Macklem Date: Thu, 6 Jul 2017 22:04:37 +0000 Subject: [PATCH] Modify the nfsuserd daemon so that it uses an AF_LOCAL socket for upcalls. This patch modifies the nfsuserd daemon so that it uses an AF_LOCAL socket for upcalls by default. This should fix the problem with using a UDP socket upcall to 127.0.0.1 when jails are used. The AF_LOCAL socket case only supports a single server daemon, since hangs were observed by the original problem reporter when multiple daemons were used. The patch adds a command line option called "-use-udpsock" which makes the daemon revert to its prepatched behaviour. Suggested by: dfr PR: 205193 Relnotes: yes --- usr.sbin/nfsuserd/nfsuserd.c | 172 ++++++++++++++++++++++++----------- 1 file changed, 117 insertions(+), 55 deletions(-) diff --git a/usr.sbin/nfsuserd/nfsuserd.c b/usr.sbin/nfsuserd/nfsuserd.c index 413e5cedbb9b..761d01d937f6 100644 --- a/usr.sbin/nfsuserd/nfsuserd.c +++ b/usr.sbin/nfsuserd/nfsuserd.c @@ -35,6 +35,7 @@ __FBSDID("$FreeBSD$"); #include #include #include +#include #include #include #include @@ -43,6 +44,7 @@ __FBSDID("$FreeBSD$"); #include #include +#include #include #include @@ -73,6 +75,9 @@ static bool_t xdr_getid(XDR *, caddr_t); static bool_t xdr_getname(XDR *, caddr_t); static bool_t xdr_retval(XDR *, caddr_t); +#ifndef _PATH_NFSUSERDSOCK +#define _PATH_NFSUSERDSOCK "/var/run/nfsuserd.sock" +#endif #define MAXNAME 1024 #define MAXNFSUSERD 20 #define DEFNFSUSERD 4 @@ -92,6 +97,7 @@ uid_t defaultuid = 65534; u_char *defaultgroup = "nogroup"; gid_t defaultgid = 65533; int verbose = 0, im_a_slave = 0, nfsuserdcnt = -1, forcestart = 0; +int use_udpsock = 0; int defusertimeout = DEFUSERTIMEOUT, manage_gids = 0; pid_t slaves[MAXNFSUSERD]; @@ -103,15 +109,17 @@ main(int argc, char *argv[]) struct nfsd_idargs nid; struct passwd *pwd; struct group *grp; - int sock, one = 1; + int oldmask, one = 1, sock; SVCXPRT *udptransp; u_short portnum; + SVCXPRT *xprt; sigset_t signew; char hostname[MAXHOSTNAMELEN + 1], *cp; struct addrinfo *aip, hints; static uid_t check_dups[MAXUSERMAX]; gid_t grps[NGROUPS]; int ngroup; + struct sockaddr_un sun; if (modfind("nfscommon") < 0) { /* Not present in kernel, try loading it */ @@ -164,6 +172,8 @@ main(int argc, char *argv[]) forcestart = 1; } else if (!strcmp(*argv, "-manage-gids")) { manage_gids = 1; + } else if (!strcmp(*argv, "-use-udpsock")) { + use_udpsock = 1; } else if (!strcmp(*argv, "-usermax")) { if (argc == 1) usage(); @@ -207,6 +217,9 @@ main(int argc, char *argv[]) } if (nfsuserdcnt < 1) nfsuserdcnt = DEFNFSUSERD; + if (use_udpsock == 0) + /* For AF_LOCAL socket, only allow one server daemon. */ + nfsuserdcnt = 1; /* * Strip off leading and trailing '.'s in domain name and map @@ -245,49 +258,93 @@ main(int argc, char *argv[]) for (i = 0; i < nfsuserdcnt; i++) slaves[i] = (pid_t)-1; - /* - * Set up the service port to accept requests via UDP from - * localhost (127.0.0.1). - */ - if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) - err(1, "cannot create udp socket"); - - /* - * Not sure what this does, so I'll leave it here for now. - */ - setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + if (use_udpsock != 0) { + /* + * Set up the service port to accept requests via UDP from + * localhost (127.0.0.1). + */ + if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) + err(1, "cannot create udp socket"); - if ((udptransp = svcudp_create(sock)) == NULL) - err(1, "Can't set up socket"); - - /* - * By not specifying a protocol, it is linked into the - * dispatch queue, but not registered with portmapper, - * which is just what I want. - */ - if (!svc_register(udptransp, RPCPROG_NFSUSERD, RPCNFSUSERD_VERS, - nfsuserdsrv, 0)) - err(1, "Can't register nfsuserd"); - - /* - * Tell the kernel what my port# is. - */ - portnum = htons(udptransp->xp_port); + /* + * Not sure what this does, so I'll leave it here for now. + */ + setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); + + if ((udptransp = svcudp_create(sock)) == NULL) + err(1, "Can't set up socket"); + + /* + * By not specifying a protocol, it is linked into the + * dispatch queue, but not registered with portmapper, + * which is just what I want. + */ + if (!svc_register(udptransp, RPCPROG_NFSUSERD, RPCNFSUSERD_VERS, + nfsuserdsrv, 0)) + err(1, "Can't register nfsuserd"); + + /* + * Tell the kernel what my port# is. + */ + portnum = htons(udptransp->xp_port); #ifdef DEBUG - printf("portnum=0x%x\n", portnum); + printf("portnum=0x%x\n", portnum); #else - if (nfssvc(NFSSVC_NFSUSERDPORT, (caddr_t)&portnum) < 0) { - if (errno == EPERM) { - fprintf(stderr, - "Can't start nfsuserd when already running"); - fprintf(stderr, - " If not running, use the -force option.\n"); - } else { - fprintf(stderr, "Can't do nfssvc() to add port\n"); + if (nfssvc(NFSSVC_NFSUSERDPORT, (caddr_t)&portnum) < 0) { + if (errno == EPERM) + fprintf(stderr, "Can't start nfsuserd when" + " already running\nIf not running," + " use the -force option.\n"); + else + fprintf(stderr, + "Can't do nfssvc() to add socket\n"); + exit(1); } - exit(1); - } #endif + } else { + /* Use the AF_LOCAL socket. */ + memset(&sun, 0, sizeof sun); + sun.sun_family = AF_LOCAL; + unlink(_PATH_NFSUSERDSOCK); + strcpy(sun.sun_path, _PATH_NFSUSERDSOCK); + sun.sun_len = SUN_LEN(&sun); + sock = socket(AF_LOCAL, SOCK_STREAM, 0); + if (sock < 0) + err(1, "Can't create local nfsuserd socket"); + oldmask = umask(S_IXUSR | S_IRWXG | S_IRWXO); + if (bind(sock, (struct sockaddr *)&sun, sun.sun_len) < 0) + err(1, "Can't bind local nfsuserd socket"); + umask(oldmask); + if (listen(sock, SOMAXCONN) < 0) + err(1, "Can't listen on local nfsuserd socket"); + xprt = svc_vc_create(sock, RPC_MAXDATASIZE, RPC_MAXDATASIZE); + if (xprt == NULL) + err(1, + "Can't create transport for local nfsuserd socket"); + if (!svc_reg(xprt, RPCPROG_NFSUSERD, RPCNFSUSERD_VERS, + nfsuserdsrv, NULL)) + err(1, + "Can't register service for local nfsuserd socket"); + + /* + * Tell the kernel what the socket's path is. + */ +#ifdef DEBUG + printf("sockpath=%s\n", _PATH_NFSUSERDSOCK); +#else + if (nfssvc(NFSSVC_NFSUSERDPORT | NFSSVC_NEWSTRUCT, + _PATH_NFSUSERDSOCK) < 0) { + if (errno == EPERM) + fprintf(stderr, "Can't start nfsuserd when" + " already running\nIf not running," + " use the -force option.\n"); + else + fprintf(stderr, + "Can't do nfssvc() to add socket\n"); + exit(1); + } +#endif + } pwd = getpwnam(defaultuser); if (pwd) @@ -462,21 +519,25 @@ nfsuserdsrv(struct svc_req *rqstp, SVCXPRT *transp) gid_t grps[NGROUPS]; int ngroup; - /* - * Only handle requests from 127.0.0.1 on a reserved port number. - * (Since a reserved port # at localhost implies a client with - * local root, there won't be a security breach. This is about - * the only case I can think of where a reserved port # means - * something.) - */ - sport = ntohs(transp->xp_raddr.sin_port); - saddr = ntohl(transp->xp_raddr.sin_addr.s_addr); - if ((rqstp->rq_proc != NULLPROC && sport >= IPPORT_RESERVED) || - saddr != 0x7f000001) { - syslog(LOG_ERR, "req from ip=0x%x port=%d\n", saddr, sport); - svcerr_weakauth(transp); - return; + if (use_udpsock != 0) { + /* + * Only handle requests from 127.0.0.1 on a reserved port + * number. (Since a reserved port # at localhost implies a + * client with local root, there won't be a security breach. + * This is about the only case I can think of where a reserved + * port # means something.) + */ + sport = ntohs(transp->xp_raddr.sin_port); + saddr = ntohl(transp->xp_raddr.sin_addr.s_addr); + if ((rqstp->rq_proc != NULLPROC && sport >= IPPORT_RESERVED) || + saddr != 0x7f000001) { + syslog(LOG_ERR, "req from ip=0x%x port=%d, consider" + " using an AF_LOCAL socket\n", saddr, sport); + svcerr_weakauth(transp); + return; + } } + switch (rqstp->rq_proc) { case NULLPROC: if (!svc_sendreply(transp, (xdrproc_t)xdr_void, NULL)) @@ -720,6 +781,7 @@ static void usage(void) { - errx(1, - "usage: nfsuserd [-usermax cache_size] [-usertimeout minutes] [-verbose] [-manage-gids] [-domain domain_name] [n]"); + errx(1, "usage: nfsuserd [-usermax cache_size] [-usertimeout minutes]" + " [-verbose] [-manage-gids] [-use-udpsock] [-domain domain_name]" + " [n]"); }