xref: /illumos-gate/usr/src/cmd/fm/fmd/common/fmd_rpc.c (revision 45ede40b2394db7967e59f19288fae9b62efd4aa)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2004, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 
25 #include <sys/types.h>
26 #include <sys/fm/util.h>
27 
28 #include <netdir.h>
29 #include <strings.h>
30 #include <alloca.h>
31 #include <limits.h>
32 #include <unistd.h>
33 #include <ucred.h>
34 #include <priv.h>
35 
36 #include <fmd_rpc_api.h>
37 #include <fmd_rpc_adm.h>
38 #include <rpc/svc_mt.h>
39 
40 #include <fmd_subr.h>
41 #include <fmd_error.h>
42 #include <fmd_thread.h>
43 #include <fmd_conf.h>
44 #include <fmd_api.h>
45 #include <fmd.h>
46 
47 /*
48  * Define range of transient RPC program numbers to use for transient bindings.
49  * These are defined in the Solaris ONC+ Developer's Guide, Appendix B, but
50  * are cleverly not defined in any ONC+ standard system header file.
51  */
52 #define	RPC_TRANS_MIN	0x40000000
53 #define	RPC_TRANS_MAX	0x5fffffff
54 
55 /*
56  * We use our own private version of svc_create() which registers our services
57  * only on loopback transports and enables an option whereby Solaris ucreds
58  * are associated with each connection, permitting us to check privilege bits.
59  */
60 static int
61 fmd_rpc_svc_create_local(void (*disp)(struct svc_req *, SVCXPRT *),
62     rpcprog_t prog, rpcvers_t vers, uint_t ssz, uint_t rsz, int force)
63 {
64 	struct netconfig *ncp;
65 	struct netbuf buf;
66 	SVCXPRT *xprt;
67 	void *hdl;
68 	int fd, n = 0;
69 
70 	char door[PATH_MAX];
71 	time_t tm;
72 
73 	if ((hdl = setnetconfig()) == NULL) {
74 		fmd_error(EFMD_RPC_REG, "failed to iterate over "
75 		    "netconfig database: %s\n", nc_sperror());
76 		return (fmd_set_errno(EFMD_RPC_REG));
77 	}
78 
79 	if (force)
80 		svc_unreg(prog, vers); /* clear stale rpcbind registrations */
81 
82 	buf.buf = alloca(_SS_MAXSIZE);
83 	buf.maxlen = _SS_MAXSIZE;
84 	buf.len = 0;
85 
86 	while ((ncp = getnetconfig(hdl)) != NULL) {
87 		if (strcmp(ncp->nc_protofmly, NC_LOOPBACK) != 0)
88 			continue;
89 
90 		if (!force && rpcb_getaddr(prog, vers, ncp, &buf, HOST_SELF)) {
91 			(void) endnetconfig(hdl);
92 			return (fmd_set_errno(EFMD_RPC_BOUND));
93 		}
94 
95 		if ((fd = t_open(ncp->nc_device, O_RDWR, NULL)) == -1) {
96 			fmd_error(EFMD_RPC_REG, "failed to open %s: %s\n",
97 			    ncp->nc_device, t_strerror(t_errno));
98 			continue;
99 		}
100 
101 		svc_fd_negotiate_ucred(fd); /* enable ucred option on xprt */
102 
103 		if ((xprt = svc_tli_create(fd, ncp, NULL, ssz, rsz)) == NULL) {
104 			(void) t_close(fd);
105 			continue;
106 		}
107 
108 		if (svc_reg(xprt, prog, vers, disp, ncp) == FALSE) {
109 			fmd_error(EFMD_RPC_REG, "failed to register "
110 			    "rpc service on %s\n", ncp->nc_netid);
111 			svc_destroy(xprt);
112 			continue;
113 		}
114 
115 		n++;
116 	}
117 
118 	(void) endnetconfig(hdl);
119 
120 	/*
121 	 * If we failed to register services (n == 0) because rpcbind is down,
122 	 * then check to see if the RPC door file exists before attempting an
123 	 * svc_door_create(), which cleverly destroys any existing door file.
124 	 * The RPC APIs have no stable errnos, so we use rpcb_gettime() as a
125 	 * hack to determine if rpcbind itself is down.
126 	 */
127 	if (!force && n == 0 && rpcb_gettime(HOST_SELF, &tm) == FALSE &&
128 	    snprintf(door, sizeof (door), RPC_DOOR_RENDEZVOUS,
129 	    prog, vers) > 0 && access(door, F_OK) == 0)
130 		return (fmd_set_errno(EFMD_RPC_BOUND));
131 
132 	/*
133 	 * Attempt to create a door server for the RPC program as well.  Limit
134 	 * the maximum request size for the door transport to the receive size.
135 	 */
136 	if ((xprt = svc_door_create(disp, prog, vers, ssz)) == NULL) {
137 		fmd_error(EFMD_RPC_REG, "failed to create door for "
138 		    "rpc service 0x%lx/0x%lx\n", prog, vers);
139 	} else {
140 		(void) svc_control(xprt, SVCSET_CONNMAXREC, &rsz);
141 		n++;
142 	}
143 
144 	return (n);
145 }
146 
147 static int
148 fmd_rpc_svc_init(void (*disp)(struct svc_req *, SVCXPRT *),
149     const char *name, const char *path, const char *prop,
150     rpcprog_t pmin, rpcprog_t pmax, rpcvers_t vers,
151     uint_t sndsize, uint_t rcvsize, int force)
152 {
153 	rpcprog_t prog;
154 	char buf[16];
155 	FILE *fp;
156 
157 	for (prog = pmin; prog <= pmax; prog++) {
158 		if (fmd_rpc_svc_create_local(disp, prog, vers,
159 		    sndsize, rcvsize, force) > 0) {
160 			fmd_dprintf(FMD_DBG_RPC, "registered %s rpc service "
161 			    "as 0x%lx.%lx\n", name, prog, vers);
162 
163 			/*
164 			 * To aid simulator scripts, save our RPC "digits" in
165 			 * the specified file for rendezvous with libfmd_adm.
166 			 */
167 			if (path != NULL && (fp = fopen(path, "w")) != NULL) {
168 				(void) fprintf(fp, "%ld\n", prog);
169 				(void) fclose(fp);
170 			}
171 
172 			(void) snprintf(buf, sizeof (buf), "%ld", prog);
173 			(void) fmd_conf_setprop(fmd.d_conf, prop, buf);
174 
175 			return (0);
176 		}
177 	}
178 
179 	return (-1); /* errno is set for us */
180 }
181 
182 void
183 fmd_rpc_init(void)
184 {
185 	int err, prog, mode = RPC_SVC_MT_USER;
186 	uint64_t sndsize = 0, rcvsize = 0;
187 	const char *s;
188 
189 	if (rpc_control(RPC_SVC_MTMODE_SET, &mode) == FALSE)
190 		fmd_panic("failed to enable user-MT rpc mode");
191 
192 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.sndsize", &sndsize);
193 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.rcvsize", &rcvsize);
194 
195 	/*
196 	 * Infer whether we are the "default" fault manager or an alternate one
197 	 * based on whether the initial setting of rpc.adm.prog is non-zero.
198 	 */
199 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.adm.prog", &prog);
200 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.adm.path", &s);
201 
202 	if (prog != 0) {
203 		err = fmd_rpc_svc_init(fmd_adm_1, "FMD_ADM", s, "rpc.adm.prog",
204 		    FMD_ADM, FMD_ADM, FMD_ADM_VERSION_1,
205 		    (uint_t)sndsize, (uint_t)rcvsize, TRUE);
206 	} else {
207 		err = fmd_rpc_svc_init(fmd_adm_1, "FMD_ADM", s, "rpc.adm.prog",
208 		    RPC_TRANS_MIN, RPC_TRANS_MAX, FMD_ADM_VERSION_1,
209 		    (uint_t)sndsize, (uint_t)rcvsize, FALSE);
210 	}
211 
212 	if (err != 0)
213 		fmd_error(EFMD_EXIT, "failed to create rpc server bindings");
214 
215 	if (fmd_thread_create(fmd.d_rmod, (fmd_thread_f *)svc_run, 0) == NULL)
216 		fmd_error(EFMD_EXIT, "failed to create rpc server thread");
217 }
218 
219 void
220 fmd_rpc_fini(void)
221 {
222 	rpcprog_t prog;
223 
224 	svc_exit(); /* force svc_run() threads to exit */
225 
226 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.adm.prog", &prog);
227 	svc_unreg(prog, FMD_ADM_VERSION_1);
228 
229 	(void) fmd_conf_getprop(fmd.d_conf, "rpc.api.prog", &prog);
230 	svc_unreg(prog, FMD_API_VERSION_1);
231 }
232 
233 /*
234  * Utillity function to fetch the XPRT's ucred and determine if we should deny
235  * the request.  For now, we implement a simple policy of rejecting any caller
236  * who does not have the PRIV_SYS_ADMIN bit in their Effective privilege set,
237  * unless the caller is loading a module, which requires all privileges.
238  */
239 int
240 fmd_rpc_deny(struct svc_req *rqp)
241 {
242 	ucred_t *ucp = alloca(ucred_size());
243 	const priv_set_t *psp;
244 
245 	if (!fmd.d_booted) {
246 		(void) pthread_mutex_lock(&fmd.d_fmd_lock);
247 		while (!fmd.d_booted)
248 			(void) pthread_cond_wait(&fmd.d_fmd_cv,
249 			    &fmd.d_fmd_lock);
250 		(void) pthread_mutex_unlock(&fmd.d_fmd_lock);
251 	}
252 
253 	if (svc_getcallerucred(rqp->rq_xprt, &ucp) != 0 ||
254 	    (psp = ucred_getprivset(ucp, PRIV_EFFECTIVE)) == NULL)
255 		return (1); /* deny access if we can't get credentials */
256 
257 #ifndef DEBUG
258 	/*
259 	 * For convenience of testing, we only require all privileges for a
260 	 * module load when running a non-DEBUG fault management daemon.
261 	 */
262 	if (rqp->rq_proc == FMD_ADM_MODLOAD)
263 		return (!priv_isfullset(psp));
264 #endif
265 	return (!priv_ismember(psp, PRIV_SYS_ADMIN));
266 }
267