3 * daemon code which executes actual service (ie child process)
5 * Copyright (C)1996-1997 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_version(const char *const *argv) {
62 const unsigned char *p;
65 printf("uservd version " VERSION VEREXT "; copyright (C)1996-1997 Ian Jackson.\n"
71 " - protocol magic number %08lx\n"
72 "maximums: fd %-10d general string %d\n"
73 " gids %-10d override length %d\n"
74 " args or variables %-10d error message %d\n"
75 " nested inclusion %-10d errno string reserve %d\n"
76 "protocol checksum: ",
78 MAX_ALLOW_FD, MAX_GENERAL_STRING,
79 MAX_GIDS, MAX_OVERRIDE_LEN,
80 MAX_ARGSDEFVAR, MAX_ERRMSG_LEN,
81 MAX_INCLUDE_NEST, ERRMSG_RESERVE_ERRNO);
82 for (i=0, p=protocolchecksumversion; i<sizeof(protocolchecksumversion); i++, p++)
85 "rendezvous socket: `" RENDEZVOUSPATH "'\n"
86 "system config dir: `" SYSTEMCONFIGDIR "'\n"
87 "pipe filename format: `%s' (max length %d)\n",
88 PIPEFORMAT, PIPEMAXLEN);
89 serv_checkstdoutexit();
92 static void NONRETURNING dumpconfig(const char *string) {
97 while ((c= *string++)) {
99 case ' ': nspaces++; break;
101 if (!lnl) putchar('\n');
105 while (nspaces>0) { putchar(' '); nspaces--; }
112 serv_checkstdoutexit();
115 void bisexec_toplevel(const char *const *argv) {
116 dumpconfig(TOPLEVEL_CONFIGURATION);
119 void bisexec_override(const char *const *argv) {
120 dumpconfig(TOPLEVEL_OVERRIDDEN_CONFIGURATION);
123 void bisexec_reset(const char *const *argv) {
124 dumpconfig(RESET_CONFIGURATION);
127 void bisexec_execute(const char *const *argv) {
128 always_dumpexecsettings();
129 serv_checkstdoutexit();
132 static void serv_resetsignal(int signo) {
133 struct sigaction sig;
135 sig.sa_handler= SIG_DFL;
136 sigemptyset(&sig.sa_mask);
138 if (sigaction(signo,&sig,0)) serv_syscallfail("reset signal handler");
141 static const char *see_logname(void) { return serviceuser; }
142 static const char *see_home(void) { return serviceuser_dir; }
143 static const char *see_shell(void) { return serviceuser_shell; }
145 static const char *see_service(void) { return service; }
146 static const char *see_c_cwd(void) { return cwd; }
147 static const char *see_c_logname(void) { return logname; }
148 static const char *see_c_uid(void) {
149 static char buf[CHAR_BIT*sizeof(uid_t)/3+4];
150 snyprintf(buf,sizeof(buf),"%lu",(unsigned long)request_mbuf.callinguid);
154 static const char *see_c_list(int n, const char *(*fn)(int i)) {
158 for (i=0, l=1; i<n; i++) l+= strlen(fn(i))+1;
159 r= xmalloc(l); r[l-1]= '*';
160 for (i=0, *r=0; i<n; i++) snytprintfcat(r,l,"%s ",fn(i));
161 assert(!r[l-1] && r[l-2]==' ');
166 static const char *seei_group(int i) {
167 return calling_groups[i];
169 static const char *see_c_group(void) {
170 return see_c_list(request_mbuf.ngids,seei_group);
173 static const char *seei_gid(int i) {
174 static char buf[CHAR_BIT*sizeof(gid_t)/3+4];
176 snyprintf(buf,sizeof(buf),"%d",calling_gids[i]);
179 static const char *see_c_gid(void) {
180 return see_c_list(request_mbuf.ngids,seei_gid);
183 static const struct serv_envinfo {
185 const char *(*fn)(void);
187 { "USER", see_logname },
188 { "LOGNAME", see_logname },
189 { "HOME", see_home },
190 { "SHELL", see_shell },
191 { "PATH", defaultpath },
192 { "USERV_SERVICE", see_service },
193 { "USERV_CWD", see_c_cwd },
194 { "USERV_USER", see_c_logname },
195 { "USERV_UID", see_c_uid },
196 { "USERV_GROUP", see_c_group },
197 { "USERV_GID", see_c_gid },
201 void execservice(const int synchsocket[], int clientfd) {
202 static const char *const setenvpfargs[]= {
205 ". " SETENVIRONMENTPATH "; exec \"$@\"",
209 int fd, realfd, holdfd, newfd, r, envvarbufsize=0, targ, nargs, i, l;
211 const char **args, *const *cpp;
214 const struct serv_envinfo *sei;
216 if (dup2(fdarray[2].realfd,2)<0) {
217 static const char duperrmsg[]= "uservd(service): cannot dup2 for stderr\n";
218 write(fdarray[2].realfd,duperrmsg,sizeof(duperrmsg)-1);
221 serv_resetsignal(SIGPIPE);
222 serv_resetsignal(SIGCHLD);
224 if (close(synchsocket[0])) serv_syscallfail("close parent synch socket");
226 if (setpgid(0,0)) serv_syscallfail("set process group");
228 r= write(synchsocket[1],&synchmsg,1);
229 if (r!=1) serv_syscallfail("write synch byte to parent");
230 r= synchread(synchsocket[1],'g');
231 if (r) serv_syscallfail("reach synch byte from parent");
233 if (close(clientfd)) serv_syscallfail("close client socket fd");
235 /* Now we have to make all the fd's work. It's rather a complicated
236 * algorithm, unfortunately. We remember in holdfd[fd] whether fd
237 * is being used to hold a file descriptor we actually want for some
238 * other real fd in the service program; holdfd[fd] contains the fd
239 * we eventually want fd to be dup'd into, so that realfd[holdfd[fd]]==fd.
240 * After setting up the holdfds we go through the fds in order of
241 * eventual fd making sure that fd is the one we want it to be. If the
242 * holdfd tells us we're currently storing some other fd in there we
243 * move it out of the way with dup and record its new location.
245 for (fd=0; fd<fdarrayused; fd++) {
246 if (fdarray[fd].holdfd == -1) continue;
247 if (close(fdarray[fd].holdfd)) serv_syscallfail("close pipe hold fd");
248 fdarray[fd].holdfd= -1;
250 for (fd=0; fd<fdarrayused; fd++) {
251 if (fdarray[fd].realfd < fdarrayused) fdarray[fdarray[fd].realfd].holdfd= fd;
253 for (fd=0; fd<fdarrayused; fd++) {
254 realfd= fdarray[fd].realfd;
255 if (realfd == -1) continue;
256 holdfd= fdarray[fd].holdfd;
258 assert(realfd == fd);
259 fdarray[fd].holdfd= -1;
261 } else if (holdfd != -1) {
262 assert(fdarray[holdfd].realfd == fd);
263 newfd= dup(fd); if (newfd<0) serv_syscallfail("dup out of the way");
264 fdarray[holdfd].realfd= newfd;
265 if (newfd<fdarrayused) fdarray[newfd].holdfd= holdfd;
266 fdarray[fd].holdfd= -1;
268 if (dup2(fdarray[fd].realfd,fd)<0) serv_syscallfail("dup2 set up fd");
269 if (close(fdarray[fd].realfd)) serv_syscallfail("close old fd");
270 if (fcntl(fd,F_SETFD,0)<0) serv_syscallfail("set no-close-on-exec on fd");
271 fdarray[fd].realfd= fd;
274 for (sei= serv_envinfos; sei->name; sei++)
275 if (setenv(sei->name,sei->fn(),1)) serv_syscallfail("setenv standard");
276 for (i=0; i<request_mbuf.nvars; i++) {
277 l= strlen(defvararray[i].key)+9;
278 if (l>envvarbufsize) { envvarbufsize= l; envvarbuf= xrealloc(envvarbuf,l); }
279 snyprintf(envvarbuf,l,"USERV_U_%s",defvararray[i].key);
280 if (setenv(envvarbuf,defvararray[i].value,1)) serv_syscallfail("setenv defvar");
284 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) nargs++;
286 if (execargs) for (pp= execargs; *pp; pp++) nargs++;
287 if (!suppressargs) nargs+= request_mbuf.nargs;
288 args= xmalloc(sizeof(char*)*(nargs+1));
290 if (setenvironment) for (cpp= setenvpfargs; *cpp; cpp++) args[targ++]= *cpp;
291 args[targ++]= execpath;
292 if (execargs) for (pp= execargs; *pp; pp++) args[targ++]= *pp;
293 if (!suppressargs) for (i=0; i<request_mbuf.nargs; i++) args[targ++]= argarray[i];
299 execv(args[0],(char* const*)args);
301 serv_syscallfail("exec service program");