1 /* userdel.c - delete a user
2 *
3 * Copyright 2014 Ashwini Kumar <ak.ashwini1981@gmail.com>
4 *
5 * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/userdel.html
6
7 USE_USERDEL(NEWTOY(userdel, "<1>1r", TOYFLAG_NEEDROOT|TOYFLAG_SBIN))
8 USE_USERDEL(OLDTOY(deluser, userdel, TOYFLAG_NEEDROOT|TOYFLAG_SBIN))
9
10 config USERDEL
11 bool "userdel"
12 default n
13 help
14 usage: userdel [-r] USER
15 usage: deluser [-r] USER
16
17 Delete USER from the SYSTEM
18
19 -r remove home directory
20 */
21
22 #define FOR_userdel
23 #include "toys.h"
24
update_groupfiles(char * filename,char * username)25 static void update_groupfiles(char *filename, char* username)
26 {
27 char *filenamesfx = NULL, *sfx = NULL, *line = NULL;
28 FILE *exfp, *newfp;
29 int ulen = strlen(username);
30 size_t allocated_length = 0;
31 struct flock lock;
32
33 filenamesfx = xmprintf("%s+", filename);
34 sfx = strchr(filenamesfx, '+');
35 exfp = xfopen(filename, "r+");
36
37 *sfx = '-';
38 unlink(filenamesfx);
39 if (link(filename, filenamesfx)) error_msg("Can't create backup file");
40
41 *sfx = '+';
42 lock.l_type = F_WRLCK;
43 lock.l_whence = SEEK_SET;
44 lock.l_start = lock.l_len = 0;
45
46 if (fcntl(fileno(exfp), F_SETLK, &lock) < 0)
47 perror_msg("Couldn't lock file %s",filename);
48
49 lock.l_type = F_UNLCK; //unlocking at a later stage
50
51 newfp = xfopen(filenamesfx, "w+");
52
53 while (getline(&line, &allocated_length, exfp) > 0) {
54 sprintf(toybuf, "%s:",username);
55 if (strncmp(line, toybuf, ulen+1)) {
56 char *n, *p = strrchr(line, ':');
57
58 if (p && *++p && (n = strstr(p, username))) {
59 do {
60 if (n[ulen] == ',') {
61 *n = '\0';
62 n += ulen + 1;
63 fprintf(newfp, "%s%s\n", line, n);
64 break;
65 } else if (!n[ulen]) {
66 if (n[-1] == ',') n[-1] = *n = '\0';
67 if (n[-1] == ':') *n = '\0';
68 fprintf(newfp, "%s%s\n", line, n);
69 break;
70 } else n += ulen;
71 } while (*n && (n=strstr(n, username)));
72 if (!n) fprintf(newfp, "%s\n", line);
73 } else fprintf(newfp, "%s\n", line);
74 }
75 }
76 free(line);
77 fcntl(fileno(exfp), F_SETLK, &lock);
78 fclose(exfp);
79 errno = 0;
80 fflush(newfp);
81 fsync(fileno(newfp));
82 fclose(newfp);
83 rename(filenamesfx, filename);
84 if (errno){
85 perror_msg("File Writing/Saving failed: ");
86 unlink(filenamesfx);
87 }
88 free(filenamesfx);
89 }
90
userdel_main(void)91 void userdel_main(void)
92 {
93 struct passwd *pwd = xgetpwnam(*toys.optargs);
94
95 update_password("/etc/passwd", pwd->pw_name, NULL);
96 update_password("/etc/shadow", pwd->pw_name, NULL);
97
98 // delete the group named USER, and remove user from group.
99 // could update_password() be used for this?
100 // not a good idea, as update_passwd() updates one entry at a time
101 // in this case it will be modifying the files as many times the
102 // USER appears in group database files. So the customized version
103 // of update_passwd() is here.
104 update_groupfiles("/etc/group", *toys.optargs);
105 update_groupfiles("/etc/gshadow", *toys.optargs);
106
107 if (FLAG(r)) {
108 char *arg[] = {"rm", "-fr", pwd->pw_dir, NULL, NULL};
109
110 sprintf(toybuf, "/var/spool/mail/%s",pwd->pw_name);
111 arg[3] = toybuf;
112 xexec(arg);
113 }
114 }
115