1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate * passprompt.c - pppd plugin to invoke an external PAP password prompter
3*0Sstevel@tonic-gate *
4*0Sstevel@tonic-gate * Copyright 1999 Paul Mackerras, Alan Curry.
5*0Sstevel@tonic-gate *
6*0Sstevel@tonic-gate * This program is free software; you can redistribute it and/or
7*0Sstevel@tonic-gate * modify it under the terms of the GNU General Public License
8*0Sstevel@tonic-gate * as published by the Free Software Foundation; either version
9*0Sstevel@tonic-gate * 2 of the License, or (at your option) any later version.
10*0Sstevel@tonic-gate */
11*0Sstevel@tonic-gate #include <errno.h>
12*0Sstevel@tonic-gate #include <unistd.h>
13*0Sstevel@tonic-gate #include <fcntl.h>
14*0Sstevel@tonic-gate #include <sys/wait.h>
15*0Sstevel@tonic-gate #include <syslog.h>
16*0Sstevel@tonic-gate #include "pppd.h"
17*0Sstevel@tonic-gate
18*0Sstevel@tonic-gate static char promptprog[PATH_MAX+1];
19*0Sstevel@tonic-gate
20*0Sstevel@tonic-gate static option_t options[] = {
21*0Sstevel@tonic-gate { "promptprog", o_string, promptprog,
22*0Sstevel@tonic-gate "External PAP password prompting program",
23*0Sstevel@tonic-gate OPT_STATIC, NULL, PATH_MAX },
24*0Sstevel@tonic-gate { NULL }
25*0Sstevel@tonic-gate };
26*0Sstevel@tonic-gate
promptpass(char * user,char * passwd)27*0Sstevel@tonic-gate static int promptpass(char *user, char *passwd)
28*0Sstevel@tonic-gate {
29*0Sstevel@tonic-gate int p[2];
30*0Sstevel@tonic-gate pid_t kid;
31*0Sstevel@tonic-gate int readgood, wstat;
32*0Sstevel@tonic-gate int red;
33*0Sstevel@tonic-gate
34*0Sstevel@tonic-gate if (promptprog[0] == 0 || access(promptprog, X_OK) < 0)
35*0Sstevel@tonic-gate return -1; /* sorry, can't help */
36*0Sstevel@tonic-gate
37*0Sstevel@tonic-gate /* This occurs when we're probed for the ability to supply a password */
38*0Sstevel@tonic-gate if (user != NULL && passwd == NULL)
39*0Sstevel@tonic-gate return 1;
40*0Sstevel@tonic-gate
41*0Sstevel@tonic-gate if (pipe(p)) {
42*0Sstevel@tonic-gate warn("Can't make a pipe for %s", promptprog);
43*0Sstevel@tonic-gate return 0;
44*0Sstevel@tonic-gate }
45*0Sstevel@tonic-gate if ((kid = fork()) == (pid_t) -1) {
46*0Sstevel@tonic-gate warn("Can't fork to run %s", promptprog);
47*0Sstevel@tonic-gate (void) close(p[0]);
48*0Sstevel@tonic-gate (void) close(p[1]);
49*0Sstevel@tonic-gate return 0;
50*0Sstevel@tonic-gate }
51*0Sstevel@tonic-gate if (kid == (pid_t)0) {
52*0Sstevel@tonic-gate /* we are the child, exec the program */
53*0Sstevel@tonic-gate char *argv[5], fdstr[32];
54*0Sstevel@tonic-gate
55*0Sstevel@tonic-gate sys_close();
56*0Sstevel@tonic-gate closelog();
57*0Sstevel@tonic-gate if (detached && p[1] <= 2) {
58*0Sstevel@tonic-gate (void) dup2(p[1], 3);
59*0Sstevel@tonic-gate p[1] = 3;
60*0Sstevel@tonic-gate }
61*0Sstevel@tonic-gate (void) close(p[0]);
62*0Sstevel@tonic-gate if (detached) {
63*0Sstevel@tonic-gate red = open("/etc/ppp/prompt-errors", O_WRONLY | O_APPEND | O_CREAT,
64*0Sstevel@tonic-gate 0600);
65*0Sstevel@tonic-gate (void) dup2(red, 1);
66*0Sstevel@tonic-gate (void) dup2(red, 2);
67*0Sstevel@tonic-gate }
68*0Sstevel@tonic-gate (void) seteuid(getuid());
69*0Sstevel@tonic-gate (void) setegid(getgid());
70*0Sstevel@tonic-gate argv[0] = promptprog;
71*0Sstevel@tonic-gate argv[1] = user == NULL ? "" : user;
72*0Sstevel@tonic-gate argv[2] = remote_name;
73*0Sstevel@tonic-gate slprintf(fdstr, sizeof (fdstr), "%d", p[1]);
74*0Sstevel@tonic-gate argv[3] = fdstr;
75*0Sstevel@tonic-gate argv[4] = NULL;
76*0Sstevel@tonic-gate (void) execv(*argv, argv);
77*0Sstevel@tonic-gate _exit(127);
78*0Sstevel@tonic-gate }
79*0Sstevel@tonic-gate
80*0Sstevel@tonic-gate /* we are the parent, read the password from the pipe */
81*0Sstevel@tonic-gate (void) close(p[1]);
82*0Sstevel@tonic-gate readgood = 0;
83*0Sstevel@tonic-gate do {
84*0Sstevel@tonic-gate red = read(p[0], passwd + readgood, MAXSECRETLEN-1 - readgood);
85*0Sstevel@tonic-gate if (red == 0)
86*0Sstevel@tonic-gate break;
87*0Sstevel@tonic-gate if (red < 0) {
88*0Sstevel@tonic-gate if (errno == EINTR)
89*0Sstevel@tonic-gate continue;
90*0Sstevel@tonic-gate error("Can't read secret from %s: %m", promptprog);
91*0Sstevel@tonic-gate readgood = -1;
92*0Sstevel@tonic-gate break;
93*0Sstevel@tonic-gate }
94*0Sstevel@tonic-gate readgood += red;
95*0Sstevel@tonic-gate } while (readgood < MAXSECRETLEN - 1);
96*0Sstevel@tonic-gate passwd[readgood] = 0;
97*0Sstevel@tonic-gate (void) close(p[0]);
98*0Sstevel@tonic-gate
99*0Sstevel@tonic-gate /* now wait for child to exit */
100*0Sstevel@tonic-gate while (waitpid(kid, &wstat, 0) < 0) {
101*0Sstevel@tonic-gate if (errno != EINTR) {
102*0Sstevel@tonic-gate warn("error waiting for %s: %m", promptprog);
103*0Sstevel@tonic-gate break;
104*0Sstevel@tonic-gate }
105*0Sstevel@tonic-gate }
106*0Sstevel@tonic-gate
107*0Sstevel@tonic-gate if (readgood < 0)
108*0Sstevel@tonic-gate return 0;
109*0Sstevel@tonic-gate if (readgood > 0 && passwd[--readgood] == '\n')
110*0Sstevel@tonic-gate passwd[readgood] = '\0';
111*0Sstevel@tonic-gate if (!WIFEXITED(wstat))
112*0Sstevel@tonic-gate warn("%s terminated abnormally", promptprog);
113*0Sstevel@tonic-gate if (WEXITSTATUS(wstat) != 0)
114*0Sstevel@tonic-gate warn("%s exited with code %d", promptprog, WEXITSTATUS(wstat));
115*0Sstevel@tonic-gate
116*0Sstevel@tonic-gate return 1;
117*0Sstevel@tonic-gate }
118*0Sstevel@tonic-gate
plugin_init(void)119*0Sstevel@tonic-gate void plugin_init(void)
120*0Sstevel@tonic-gate {
121*0Sstevel@tonic-gate add_options(options);
122*0Sstevel@tonic-gate pap_passwd_hook = promptpass;
123*0Sstevel@tonic-gate }
124