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>
40 static void NONRETURNING serv_syscallfail(const char *msg) {
41 fputs("uservd(service): ",stderr);
46 static void NONRETURNING serv_checkstdoutexit(void) {
47 if (ferror(stdout) || fclose(stdout)) serv_syscallfail("write stdout");
51 void bisexec_environment(const char *const *argv) {
52 execlp("env","env",(char*)0);
53 serv_syscallfail("execute `env'");
56 void bisexec_parameter(const char *const *argv) {
57 always_dumpparameter(execargs[0],execargs+1);
58 serv_checkstdoutexit();
61 void bisexec_help(const char *const *argv) {
62 const char *const *pp;
64 fputs("recognised builtin services:\n",stdout);
65 for (pp= builtinservicehelpstrings; *pp; pp++) printf(" %s\n",*pp);
66 serv_checkstdoutexit();
69 void bisexec_version(const char *const *argv) {
70 const unsigned char *p;
73 printf("uservd version " VERSION VEREXT "; copyright (C)1996-1997 Ian Jackson.\n"
79 " - protocol magic number %08lx\n"
80 "maximums: fd %-10d general string %d\n"
81 " gids %-10d override length %d\n"
82 " args or variables %-10d error message %d\n"
83 " nested inclusion %-10d errno string reserve %d\n"
84 "protocol checksum: ",
86 MAX_ALLOW_FD, MAX_GENERAL_STRING,
87 MAX_GIDS, MAX_OVERRIDE_LEN,
88 MAX_ARGSDEFVAR, MAX_ERRMSG_LEN,
89 MAX_INCLUDE_NEST, ERRMSG_RESERVE_ERRNO);
90 for (i=0, p=protocolchecksumversion; i<sizeof(protocolchecksumversion); i++, p++)
93 "rendezvous socket: `" RENDEZVOUSPATH "'\n"
94 "system config dir: `" SYSTEMCONFIGDIR "'\n"
95 "pipe filename format: `%s' (max length %d)\n",
96 PIPEFORMAT, PIPEMAXLEN);
97 serv_checkstdoutexit();
100 static void NONRETURNING dumpconfig(const char *string) {
105 while ((c= *string++)) {
107 case ' ': nspaces++; break;
109 if (!lnl) putchar('\n');
113 while (nspaces>0) { putchar(' '); nspaces--; }
120 serv_checkstdoutexit();
123 void bisexec_toplevel(const char *const *argv) {
124 dumpconfig(TOPLEVEL_CONFIGURATION);
127 void bisexec_override(const char *const *argv) {
128 dumpconfig(TOPLEVEL_OVERRIDDEN_CONFIGURATION);
131 void bisexec_reset(const char *const *argv) {
132 dumpconfig(RESET_CONFIGURATION);
135 void bisexec_execute(const char *const *argv) {
136 always_dumpexecsettings();
137 serv_checkstdoutexit();
140 void bisexec_shutdown(const char *const *argv) {
141 /* This is only reached if the serviceuser_uid test in
142 * process.c:servicerequest() fails (we have to handle the
143 * shutdown request there, unfortunately).
145 fputs("uservd: builtin service shutdown: permission denied\n",stderr);
149 static void serv_resetsignal(int signo) {
150 struct sigaction sig;
152 sig.sa_handler= SIG_DFL;
153 sigemptyset(&sig.sa_mask);
155 if (sigaction(signo,&sig,0)) serv_syscallfail("reset signal handler");
158 static const char *see_loginname(void) { return serviceuser; }
159 static const char *see_home(void) { return serviceuser_dir; }
160 static const char *see_shell(void) { return serviceuser_shell; }
162 static const char *see_service(void) { return service; }
163 static const char *see_c_cwd(void) { return cwd; }
164 static const char *see_c_loginname(void) { return loginname; }
165 static const char *see_c_uid(void) {
166 static char buf[CHAR_BIT*sizeof(uid_t)/3+4];
167 snyprintf(buf,sizeof(buf),"%lu",(unsigned long)request_mbuf.callinguid);
171 static const char *see_c_list(int n, const char *(*fn)(int i)) {
175 for (i=0, l=1; i<n; i++) l+= strlen(fn(i))+1;
176 r= xmalloc(l); r[l-1]= '*';
177 for (i=0, *r=0; i<n; i++) snytprintfcat(r,l,"%s ",fn(i));
178 assert(!r[l-1] && r[l-2]==' ');
183 static const char *seei_group(int i) {
184 return calling_groups[i];
186 static const char *see_c_group(void) {
187 return see_c_list(request_mbuf.ngids,seei_group);
190 static const char *seei_gid(int i) {
191 static char buf[CHAR_BIT*sizeof(gid_t)/3+4];
193 snyprintf(buf,sizeof(buf),"%d",calling_gids[i]);
196 static const char *see_c_gid(void) {
197 return see_c_list(request_mbuf.ngids,seei_gid);
200 static const struct serv_envinfo {
202 const char *(*fn)(void);
204 { "USER", see_loginname },
205 { "LOGNAME", see_loginname },
206 { "HOME", see_home },
207 { "SHELL", see_shell },
208 { "PATH", defaultpath },
209 { "USERV_SERVICE", see_service },
210 { "USERV_CWD", see_c_cwd },
211 { "USERV_USER", see_c_loginname },
212 { "USERV_UID", see_c_uid },
213 { "USERV_GROUP", see_c_group },
214 { "USERV_GID", see_c_gid },
218 void execservice(const int synchsocket[], int clientfd) {
219 static const char *const setenvpfargs[]= {
222 ". " SETENVIRONMENTPATH "; exec \"$@\"",
226 int fd, realfd, holdfd, newfd, r, envvarbufsize=0, targ, nargs, i, l;
228 const char **args, *const *cpp;
231 const struct serv_envinfo *sei;
233 if (dup2(fdarray[2].realfd,2)<0) {
234 static const char duperrmsg[]= "uservd(service): cannot dup2 for stderr\n";
235 write(fdarray[2].realfd,duperrmsg,sizeof(duperrmsg)-1);
238 serv_resetsignal(SIGPIPE);
239 serv_resetsignal(SIGCHLD);
241 if (close(synchsocket[0])) serv_syscallfail("close parent synch socket");
243 if (setpgid(0,0)) serv_syscallfail("set process group");
245 r= write(synchsocket[1],&synchmsg,1);
246 if (r!=1) serv_syscallfail("write synch byte to parent");
247 r= synchread(synchsocket[1],'g');
248 if (r) serv_syscallfail("reach synch byte from parent");
250 if (close(clientfd)) serv_syscallfail("close client socket fd");
252 /* Now we have to make all the fd's work. It's rather a complicated
253 * algorithm, unfortunately. We remember in holdfd[fd] whether fd
254 * is being used to hold a file descriptor we actually want for some
255 * other real fd in the service program; holdfd[fd] contains the fd
256 * we eventually want fd to be dup'd into, so that realfd[holdfd[fd]]==fd.
257 * After setting up the holdfds we go through the fds in order of
258 * eventual fd making sure that fd is the one we want it to be. If the
259 * holdfd tells us we're currently storing some other fd in there we
260 * move it out of the way with dup and record its new location.
262 for (fd=0; fd<fdarrayused; fd++) {
263 if (fdarray[fd].holdfd == -1) continue;
264 if (close(fdarray[fd].holdfd)) serv_syscallfail("close pipe hold fd");
265 fdarray[fd].holdfd= -1;
267 for (fd=0; fd<fdarrayused; fd++) {
268 if (fdarray[fd].realfd < fdarrayused) fdarray[fdarray[fd].realfd].holdfd= fd;
270 for (fd=0; fd<fdarrayused; fd++) {
271 realfd= fdarray[fd].realfd;
272 if (realfd == -1) continue;
273 holdfd= fdarray[fd].holdfd;
275 assert(realfd == fd);
276 fdarray[fd].holdfd= -1;
278 } else if (holdfd != -1) {
279 assert(fdarray[holdfd].realfd == fd);
280 newfd= dup(fd); if (newfd<0) serv_syscallfail("dup out of the way");
281 fdarray[holdfd].realfd= newfd;
282 if (newfd<fdarrayused) fdarray[newfd].holdfd= holdfd;
283 fdarray[fd].holdfd= -1;
285 if (dup2(fdarray[fd].realfd,fd)<0) serv_syscallfail("dup2 set up fd");
286 if (close(fdarray[fd].realfd)) serv_syscallfail("close old fd");
287 if (fcntl(fd,F_SETFD,0)<0) serv_syscallfail("set no-close-on-exec on fd");
288 fdarray[fd].realfd= fd;
291 for (sei= serv_envinfos; sei->name; sei++)
292 if (setenv(sei->name,sei->fn(),1)) serv_syscallfail("setenv standard");
293 for (i=0; i<request_mbuf.nvars; i++) {
294 l= strlen(defvararray[i].key)+9;
295 if (l>envvarbufsize) { envvarbufsize= l; envvarbuf= xrealloc(envvarbuf,l); }
296 snyprintf(envvarbuf,l,"USERV_U_%s",defvararray[i].key);
297 if (setenv(envvarbuf,defvararray[i].value,1)) serv_syscallfail("setenv defvar");
301 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) nargs++;
303 if (execargs) for (pp= execargs; *pp; pp++) nargs++;
304 if (!suppressargs) nargs+= request_mbuf.nargs;
305 args= xmalloc(sizeof(char*)*(nargs+1));
307 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) args[targ++]= *cpp;
308 args[targ++]= execpath;
309 if (execargs) for (pp= execargs; *pp; pp++) args[targ++]= *pp;
310 if (!suppressargs) for (i=0; i<request_mbuf.nargs; i++) args[targ++]= argarray[i];
316 execv(args[0],(char* const*)args);
318 serv_syscallfail("exec service program");