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1.1 root 1: #ifndef lint
2: static char sccsid[] = "@(#)rcmd.c 4.8 3/19/83";
3: #endif
4:
5: #include <stdio.h>
6: #include <sys/types.h>
7: #include <sys/socket.h>
8:
9: #include <netinet/in.h>
10:
11: #include <netdb.h>
12: #include <errno.h>
13:
14: extern errno;
15: char *index(), *sprintf();
16:
17: rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
18: char **ahost;
19: int rport;
20: char *locuser, *remuser, *cmd;
21: int *fd2p;
22: {
23: int s, timo = 1;
24: struct sockaddr_in sin, sin2, from;
25: char c;
26: int lport = IPPORT_RESERVED - 1;
27: struct hostent *hp;
28:
29: hp = gethostbyname(*ahost);
30: if (hp == 0) {
31: fprintf(stderr, "%s: unknown host\n", *ahost);
32: return (-1);
33: }
34: *ahost = hp->h_name;
35: retry:
36: s = rresvport(&lport);
37: if (s < 0)
38: return (-1);
39: sin.sin_family = hp->h_addrtype;
40: bcopy(hp->h_addr, (caddr_t)&sin.sin_addr, hp->h_length);
41: sin.sin_port = rport;
42: if (connect(s, (caddr_t)&sin, sizeof (sin), 0) < 0) {
43: if (errno == EADDRINUSE) {
44: close(s);
45: lport--;
46: goto retry;
47: }
48: if (errno == ECONNREFUSED && timo <= 16) {
49: (void) close(s);
50: sleep(timo);
51: timo *= 2;
52: goto retry;
53: }
54: perror(hp->h_name);
55: return (-1);
56: }
57: lport--;
58: if (fd2p == 0) {
59: write(s, "", 1);
60: lport = 0;
61: } else {
62: char num[8];
63: int s2 = rresvport(&lport), s3;
64:
65: if (s2 < 0) {
66: (void) close(s);
67: return (-1);
68: }
69: listen(s2, 1);
70: (void) sprintf(num, "%d", lport);
71: if (write(s, num, strlen(num)+1) != strlen(num)+1) {
72: perror("write: setting up stderr");
73: (void) close(s2);
74: goto bad;
75: }
76: { int len = sizeof (from);
77: s3 = accept(s2, &from, &len, 0);
78: close(s2);
79: if (s3 < 0) {
80: perror("accept");
81: lport = 0;
82: goto bad;
83: }
84: }
85: *fd2p = s3;
86: from.sin_port = ntohs((u_short)from.sin_port);
87: if (from.sin_family != AF_INET ||
88: from.sin_port >= IPPORT_RESERVED) {
89: fprintf(stderr,
90: "socket: protocol failure in circuit setup.\n");
91: goto bad2;
92: }
93: }
94: (void) write(s, locuser, strlen(locuser)+1);
95: (void) write(s, remuser, strlen(remuser)+1);
96: (void) write(s, cmd, strlen(cmd)+1);
97: if (read(s, &c, 1) != 1) {
98: perror(*ahost);
99: goto bad2;
100: }
101: if (c != 0) {
102: while (read(s, &c, 1) == 1) {
103: (void) write(2, &c, 1);
104: if (c == '\n')
105: break;
106: }
107: goto bad2;
108: }
109: return (s);
110: bad2:
111: if (lport)
112: (void) close(*fd2p);
113: bad:
114: (void) close(s);
115: return (-1);
116: }
117:
118: rresvport(alport)
119: int *alport;
120: {
121: struct sockaddr_in sin;
122: int s;
123:
124: sin.sin_family = AF_INET;
125: sin.sin_addr.s_addr = 0;
126: s = socket(AF_INET, SOCK_STREAM, 0, 0);
127: if (s < 0)
128: return (-1);
129: for (;;) {
130: sin.sin_port = htons((u_short)*alport);
131: if (bind(s, (caddr_t)&sin, sizeof (sin), 0) >= 0)
132: return (s);
133: if (errno != EADDRINUSE && errno != EADDRNOTAVAIL) {
134: perror("socket");
135: return (-1);
136: }
137: (*alport)--;
138: if (*alport == IPPORT_RESERVED/2) {
139: fprintf(stderr, "socket: All ports in use\n");
140: return (-1);
141: }
142: }
143: }
144:
145: ruserok(rhost, superuser, ruser, luser)
146: char *rhost;
147: int superuser;
148: char *ruser, *luser;
149: {
150: FILE *hostf;
151: char ahost[32];
152: int first = 1;
153:
154: hostf = superuser ? (FILE *)0 : fopen("/etc/hosts.equiv", "r");
155: again:
156: if (hostf) {
157: while (fgets(ahost, sizeof (ahost), hostf)) {
158: char *user;
159: if (index(ahost, '\n'))
160: *index(ahost, '\n') = 0;
161: user = index(ahost, ' ');
162: if (user)
163: *user++ = 0;
164: if (!strcmp(rhost, ahost) &&
165: !strcmp(ruser, user ? user : luser)) {
166: (void) fclose(hostf);
167: return (0);
168: }
169: }
170: (void) fclose(hostf);
171: }
172: if (first == 1) {
173: first = 0;
174: hostf = fopen(".rhosts", "r");
175: goto again;
176: }
177: return (-1);
178: }
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