169 lines
2.8 KiB
C
169 lines
2.8 KiB
C
#include <u.h>
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#include <libc.h>
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#include <auth.h>
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int maxprocs;
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int verbose;
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int trusted;
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int oneshot;
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char *nsfile;
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void
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usage(void)
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{
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fprint(2, "usage: listen1 [-1tv] [-p maxprocs] [-n namespace] address cmd args...\n");
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exits("usage");
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}
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void
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becomenone(void)
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{
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if(procsetuser("none") < 0)
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sysfatal("can't become none: %r");
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if(newns("none", nsfile) < 0)
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sysfatal("can't build namespace: %r");
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}
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char*
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remoteaddr(char *dir)
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{
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static char buf[128];
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char *p;
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int n, fd;
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snprint(buf, sizeof buf, "%s/remote", dir);
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fd = open(buf, OREAD);
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if(fd < 0)
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return "";
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n = read(fd, buf, sizeof(buf));
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close(fd);
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if(n > 0){
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buf[n] = 0;
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p = strchr(buf, '!');
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if(p)
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*p = 0;
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return buf;
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}
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return "";
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}
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void
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main(int argc, char **argv)
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{
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char data[60], dir[40], ndir[40], wbuf[64];
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int ctl, nctl, fd;
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int wfd, nowait, procs;
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Dir *d;
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ARGBEGIN{
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default:
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usage();
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case '1':
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oneshot = 1;
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break;
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case 't':
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trusted = 1;
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break;
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case 'v':
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verbose = 1;
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break;
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case 'p':
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maxprocs = atoi(EARGF(usage()));
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break;
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case 'n':
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nsfile = EARGF(usage());
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break;
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}ARGEND
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if(argc < 2)
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usage();
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if(!verbose){
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close(1);
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fd = open("/dev/null", OWRITE);
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if(fd != 1){
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dup(fd, 1);
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close(fd);
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}
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}
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if(!trusted)
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becomenone();
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print("listen started\n");
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ctl = announce(argv[0], dir);
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if(ctl < 0)
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sysfatal("announce %s: %r", argv[0]);
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wfd = -1;
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nowait = RFNOWAIT;
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if(maxprocs > 0){
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snprint(wbuf, sizeof(wbuf), "/proc/%d/wait", getpid());
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if((wfd = open(wbuf, OREAD)) >= 0)
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nowait = 0;
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}
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procs = 0;
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for(;;){
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if(nowait == 0 && (procs >= maxprocs || (procs % 8) == 0))
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while(procs > 0){
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if(procs < maxprocs){
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d = dirfstat(wfd);
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if(d == nil || d->length == 0){
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free(d);
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break;
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}
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free(d);
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}
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if(read(wfd, wbuf, sizeof(wbuf)) > 0)
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procs--;
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}
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nctl = listen(dir, ndir);
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if(nctl < 0)
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sysfatal("listen %s: %r", argv[0]);
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if(!oneshot)
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switch(rfork(RFFDG|RFPROC|RFMEM|RFENVG|RFNAMEG|RFNOTEG|RFREND|nowait)){
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case 0:
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break;
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case -1:
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reject(nctl, ndir, "host overloaded");
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close(nctl);
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continue;
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default:
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close(nctl);
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procs++;
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continue;
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}
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fd = accept(nctl, ndir);
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if(fd < 0){
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fprint(2, "accept %s: can't open %s/data: %r\n", argv[0], ndir);
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if(oneshot){
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close(nctl);
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continue;
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}
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exits("accept");
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}
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print("incoming call for %s from %s in %s\n", argv[0], remoteaddr(ndir), ndir);
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fprint(nctl, "keepalive");
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close(ctl);
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close(nctl);
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if(wfd >= 0)
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close(wfd);
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putenv("net", ndir);
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snprint(data, sizeof data, "%s/data", ndir);
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bind(data, "/dev/cons", MREPL);
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dup(fd, 0);
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dup(fd, 1);
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/* dup(fd, 2); keep stderr */
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close(fd);
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exec(argv[1], argv+1);
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if(argv[1][0] != '/')
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exec(smprint("/bin/%s", argv[1]), argv+1);
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fprint(2, "%s: exec: %r\n", argv0);
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exits("exec");
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}
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}
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