1 /*
2 * Copyright (c) 1988 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software written by Ken Arnold and
6 * published in UNIX Review, Vol. 6, No. 8.
7 *
8 * Redistribution and use in source and binary forms are permitted
9 * provided that the above copyright notice and this paragraph are
10 * duplicated in all such forms and that any documentation,
11 * advertising materials, and other materials related to such
12 * distribution and use acknowledge that the software was developed
13 * by the University of California, Berkeley. The name of the
14 * University may not be used to endorse or promote products derived
15 * from this software without specific prior written permission.
16 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
19 *
20 */
21
22 /* this came out of the ftpd sources; it's been modified to avoid the
23 * globbing stuff since we don't need it. also execvp instead of execv.
24 */
25
26 #ifndef lint
27 static char rcsid[] = "$Id: popen.c,v 1.5 1994/01/15 20:43:43 vixie Exp $";
28 static char sccsid[] = "@(#)popen.c 5.7 (Berkeley) 2/14/89";
29 #endif /* not lint */
30
31 #include "cron.h"
32 #include <sys/signal.h>
33
34
35 #define WANT_GLOBBING 0
36
37 /*
38 * Special version of popen which avoids call to shell. This insures noone
39 * may create a pipe to a hidden program as a side effect of a list or dir
40 * command.
41 */
42 static PID_T *pids;
43 static int fds;
44
45 FILE *
cron_popen(program,type)46 cron_popen(program, type)
47 char *program, *type;
48 {
49 register char *cp;
50 FILE *iop;
51 int argc, pdes[2];
52 PID_T pid;
53 char *argv[100];
54 #if WANT_GLOBBING
55 char **pop, *vv[2];
56 int gargc;
57 char *gargv[1000];
58 extern char **glob(), **copyblk();
59 #endif
60
61 if (*type != 'r' && *type != 'w' || type[1])
62 return(NULL);
63
64 if (!pids) {
65 if ((fds = getdtablesize()) <= 0)
66 return(NULL);
67 if (!(pids = (PID_T *)malloc((u_int)(fds * sizeof(PID_T)))))
68 return(NULL);
69 bzero((char *)pids, fds * sizeof(PID_T));
70 }
71 if (pipe(pdes) < 0)
72 return(NULL);
73
74 /* break up string into pieces */
75 for (argc = 0, cp = program;; cp = NULL)
76 if (!(argv[argc++] = strtok(cp, " \t\n")))
77 break;
78
79 #if WANT_GLOBBING
80 /* glob each piece */
81 gargv[0] = argv[0];
82 for (gargc = argc = 1; argv[argc]; argc++) {
83 if (!(pop = glob(argv[argc]))) { /* globbing failed */
84 vv[0] = argv[argc];
85 vv[1] = NULL;
86 pop = copyblk(vv);
87 }
88 argv[argc] = (char *)pop; /* save to free later */
89 while (*pop && gargc < 1000)
90 gargv[gargc++] = *pop++;
91 }
92 gargv[gargc] = NULL;
93 #endif
94
95 iop = NULL;
96 switch(pid = vfork()) {
97 case -1: /* error */
98 (void)close(pdes[0]);
99 (void)close(pdes[1]);
100 goto pfree;
101 /* NOTREACHED */
102 case 0: /* child */
103 if (*type == 'r') {
104 if (pdes[1] != 1) {
105 dup2(pdes[1], 1);
106 dup2(pdes[1], 2); /* stderr, too! */
107 (void)close(pdes[1]);
108 }
109 (void)close(pdes[0]);
110 } else {
111 if (pdes[0] != 0) {
112 dup2(pdes[0], 0);
113 (void)close(pdes[0]);
114 }
115 (void)close(pdes[1]);
116 }
117 #if WANT_GLOBBING
118 execvp(gargv[0], gargv);
119 #else
120 execvp(argv[0], argv);
121 #endif
122 _exit(1);
123 }
124 /* parent; assume fdopen can't fail... */
125 if (*type == 'r') {
126 iop = fdopen(pdes[0], type);
127 (void)close(pdes[1]);
128 } else {
129 iop = fdopen(pdes[1], type);
130 (void)close(pdes[0]);
131 }
132 pids[fileno(iop)] = pid;
133
134 pfree:
135 #if WANT_GLOBBING
136 for (argc = 1; argv[argc] != NULL; argc++) {
137 /* blkfree((char **)argv[argc]); */
138 free((char *)argv[argc]);
139 }
140 #endif
141 return(iop);
142 }
143
144 int
cron_pclose(iop)145 cron_pclose(iop)
146 FILE *iop;
147 {
148 register int fdes;
149 int omask;
150 WAIT_T stat_loc;
151 PID_T pid;
152
153 /*
154 * pclose returns -1 if stream is not associated with a
155 * `popened' command, or, if already `pclosed'.
156 */
157 if (pids == 0 || pids[fdes = fileno(iop)] == 0)
158 return(-1);
159 (void)fclose(iop);
160 omask = sigblock(sigmask(SIGINT)|sigmask(SIGQUIT)|sigmask(SIGHUP));
161 while ((pid = wait(&stat_loc)) != pids[fdes] && pid != -1)
162 ;
163 (void)sigsetmask(omask);
164 pids[fdes] = 0;
165 return (pid == -1 ? -1 : WEXITSTATUS(stat_loc));
166 }
167