3 * daemon code which executes actual service (ie child process)
5 * Copyright (C)1996-1997,1999 Ian Jackson
7 * This is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with userv; if not, write to the Free Software
19 * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 #include <sys/types.h>
41 static void NONRETURNING serv_syscallfail(const char *msg) {
42 fputs("uservd(service): ",stderr);
47 static void NONRETURNING serv_checkstdoutexit(void) {
48 if (ferror(stdout) || fclose(stdout)) serv_syscallfail("write stdout");
52 void bisexec_environment(const char *const *argv) {
53 execlp("env","env",(char*)0);
54 serv_syscallfail("execute `env'");
57 void bisexec_parameter(const char *const *argv) {
58 always_dumpparameter(execargs[0],execargs+1);
59 serv_checkstdoutexit();
62 void bisexec_help(const char *const *argv) {
63 const char *const *pp;
65 fputs("recognised builtin services:\n",stdout);
66 for (pp= builtinservicehelpstrings; *pp; pp++) printf(" %s\n",*pp);
67 serv_checkstdoutexit();
70 void bisexec_version(const char *const *argv) {
71 const unsigned char *p;
74 printf("uservd version " VERSION VEREXT "; copyright (C)1996-1997 Ian Jackson.\n"
80 " - protocol magic number %08lx\n"
81 "maximums: fd %-10d general string %d\n"
82 " gids %-10d override length %d\n"
83 " args or variables %-10d error message %d\n"
84 " nested inclusion %-10d errno string reserve %d\n"
85 "protocol checksum: ",
87 MAX_ALLOW_FD, MAX_GENERAL_STRING,
88 MAX_GIDS, MAX_OVERRIDE_LEN,
89 MAX_ARGSDEFVAR, MAX_ERRMSG_LEN,
90 MAX_INCLUDE_NEST, ERRMSG_RESERVE_ERRNO);
91 for (i=0, p=protocolchecksumversion; i<sizeof(protocolchecksumversion); i++, p++)
94 "rendezvous socket: `" RENDEZVOUSPATH "'\n"
95 "system config dir: `" SYSTEMCONFIGDIR "'\n"
96 "pipe filename format: `%s' (max length %d)\n",
97 PIPEFORMAT, PIPEMAXLEN);
98 serv_checkstdoutexit();
101 static void NONRETURNING dumpconfig(const char *string) {
106 while ((c= *string++)) {
108 case ' ': nspaces++; break;
110 if (!lnl) putchar('\n');
114 while (nspaces>0) { putchar(' '); nspaces--; }
121 serv_checkstdoutexit();
124 void bisexec_toplevel(const char *const *argv) {
125 dumpconfig(TOPLEVEL_CONFIGURATION);
128 void bisexec_override(const char *const *argv) {
129 dumpconfig(TOPLEVEL_OVERRIDDEN_CONFIGURATION);
132 void bisexec_reset(const char *const *argv) {
133 dumpconfig(RESET_CONFIGURATION);
136 void bisexec_execute(const char *const *argv) {
137 always_dumpexecsettings();
138 serv_checkstdoutexit();
141 void bisexec_shutdown(const char *const *argv) {
142 /* This is only reached if the serviceuser_uid test in
143 * process.c:servicerequest() fails (we have to handle the
144 * shutdown request there, unfortunately).
146 fputs("uservd: builtin service shutdown: permission denied\n",stderr);
150 static void serv_resetsignal(int signo) {
151 struct sigaction sig;
153 sig.sa_handler= SIG_DFL;
154 sigemptyset(&sig.sa_mask);
156 if (sigaction(signo,&sig,0)) serv_syscallfail("reset signal handler");
159 static const char *see_loginname(void) { return serviceuser; }
160 static const char *see_home(void) { return serviceuser_dir; }
161 static const char *see_shell(void) { return serviceuser_shell; }
163 static const char *see_service(void) { return service; }
164 static const char *see_c_cwd(void) { return cwd; }
165 static const char *see_c_loginname(void) { return loginname; }
166 static const char *see_c_uid(void) {
167 static char buf[CHAR_BIT*sizeof(uid_t)/3+4];
168 snyprintf(buf,sizeof(buf),"%lu",(unsigned long)request_mbuf.callinguid);
172 static const char *see_c_list(int n, const char *(*fn)(int i)) {
176 for (i=0, l=1; i<n; i++) l+= strlen(fn(i))+1;
177 r= xmalloc(l); r[l-1]= '*';
178 for (i=0, *r=0; i<n; i++) snytprintfcat(r,l,"%s ",fn(i));
179 assert(!r[l-1] && r[l-2]==' ');
184 static const char *seei_group(int i) {
185 return calling_groups[i];
187 static const char *see_c_group(void) {
188 return see_c_list(request_mbuf.ngids,seei_group);
191 static const char *seei_gid(int i) {
192 static char buf[CHAR_BIT*sizeof(gid_t)/3+4];
194 snyprintf(buf,sizeof(buf),"%d",calling_gids[i]);
197 static const char *see_c_gid(void) {
198 return see_c_list(request_mbuf.ngids,seei_gid);
201 static const struct serv_envinfo {
203 const char *(*fn)(void);
205 { "USER", see_loginname },
206 { "LOGNAME", see_loginname },
207 { "HOME", see_home },
208 { "SHELL", see_shell },
209 { "PATH", defaultpath },
210 { "USERV_SERVICE", see_service },
211 { "USERV_CWD", see_c_cwd },
212 { "USERV_USER", see_c_loginname },
213 { "USERV_UID", see_c_uid },
214 { "USERV_GROUP", see_c_group },
215 { "USERV_GID", see_c_gid },
219 void execservice(const int synchsocket[], int clientfd) {
220 static const char *const setenvpfargs[]= {
223 ". " SETENVIRONMENTPATH "; exec \"$@\"",
227 int fd, realfd, holdfd, newfd, r, envvarbufsize=0, targ, nargs, i, l;
229 const char **args, *const *cpp;
232 const struct serv_envinfo *sei;
234 if (dup2(fdarray[2].realfd,2)<0) {
235 static const char duperrmsg[]= "uservd(service): cannot dup2 for stderr\n";
236 write(fdarray[2].realfd,duperrmsg,sizeof(duperrmsg)-1);
239 serv_resetsignal(SIGPIPE);
240 serv_resetsignal(SIGCHLD);
242 if (close(synchsocket[0])) serv_syscallfail("close parent synch socket");
244 if (setpgid(0,0)) serv_syscallfail("set process group");
246 r= write(synchsocket[1],&synchmsg,1);
247 if (r!=1) serv_syscallfail("write synch byte to parent");
248 r= synchread(synchsocket[1],'g');
249 if (r) serv_syscallfail("reach synch byte from parent");
251 if (close(clientfd)) serv_syscallfail("close client socket fd");
253 /* Now we have to make all the fd's work. It's rather a complicated
254 * algorithm, unfortunately. We remember in holdfd[fd] whether fd
255 * is being used to hold a file descriptor we actually want for some
256 * other real fd in the service program; holdfd[fd] contains the fd
257 * we eventually want fd to be dup'd into, so that realfd[holdfd[fd]]==fd.
258 * After setting up the holdfds we go through the fds in order of
259 * eventual fd making sure that fd is the one we want it to be. If the
260 * holdfd tells us we're currently storing some other fd in there we
261 * move it out of the way with dup and record its new location.
263 for (fd=0; fd<fdarrayused; fd++) {
264 if (fdarray[fd].holdfd == -1) continue;
265 if (close(fdarray[fd].holdfd)) serv_syscallfail("close pipe hold fd");
266 fdarray[fd].holdfd= -1;
268 for (fd=0; fd<fdarrayused; fd++) {
269 if (fdarray[fd].realfd < fdarrayused) fdarray[fdarray[fd].realfd].holdfd= fd;
271 for (fd=0; fd<fdarrayused; fd++) {
272 realfd= fdarray[fd].realfd;
273 if (realfd == -1) continue;
274 holdfd= fdarray[fd].holdfd;
276 assert(realfd == fd);
277 fdarray[fd].holdfd= -1;
279 } else if (holdfd != -1) {
280 assert(fdarray[holdfd].realfd == fd);
281 newfd= dup(fd); if (newfd<0) serv_syscallfail("dup out of the way");
282 fdarray[holdfd].realfd= newfd;
283 if (newfd<fdarrayused) fdarray[newfd].holdfd= holdfd;
284 fdarray[fd].holdfd= -1;
286 if (dup2(fdarray[fd].realfd,fd)<0) serv_syscallfail("dup2 set up fd");
287 if (close(fdarray[fd].realfd)) serv_syscallfail("close old fd");
288 if (fcntl(fd,F_SETFD,0)<0) serv_syscallfail("set no-close-on-exec on fd");
289 fdarray[fd].realfd= fd;
292 for (sei= serv_envinfos; sei->name; sei++)
293 if (setenv(sei->name,sei->fn(),1)) serv_syscallfail("setenv standard");
294 for (i=0; i<request_mbuf.nvars; i++) {
295 l= strlen(defvararray[i].key)+9;
296 if (l>envvarbufsize) { envvarbufsize= l; envvarbuf= xrealloc(envvarbuf,l); }
297 snyprintf(envvarbuf,l,"USERV_U_%s",defvararray[i].key);
298 if (setenv(envvarbuf,defvararray[i].value,1)) serv_syscallfail("setenv defvar");
302 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) nargs++;
304 if (execargs) for (pp= execargs; *pp; pp++) nargs++;
305 if (!suppressargs) nargs+= request_mbuf.nargs;
306 args= xmalloc(sizeof(char*)*(nargs+1));
308 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) args[targ++]= *cpp;
309 args[targ++]= execpath;
310 if (execargs) for (pp= execargs; *pp; pp++) args[targ++]= *pp;
311 if (!suppressargs) for (i=0; i<request_mbuf.nargs; i++) args[targ++]= argarray[i];
317 execv(args[0],(char* const*)args);
319 serv_syscallfail("exec service program");