| 1 | #ifndef lint |
| 2 | static char sccsid[] = "@(#)vipw.c 4.1 (Berkeley) %G%"; |
| 3 | #endif |
| 4 | |
| 5 | #include <sys/types.h> |
| 6 | #include <sys/stat.h> |
| 7 | #include <sys/file.h> |
| 8 | |
| 9 | #include <stdio.h> |
| 10 | #include <errno.h> |
| 11 | #include <signal.h> |
| 12 | |
| 13 | /* |
| 14 | * Password file editor with locking. |
| 15 | */ |
| 16 | char *temp = "/etc/ptmp"; |
| 17 | char *passwd = "/etc/passwd"; |
| 18 | char buf[BUFSIZ]; |
| 19 | char *getenv(); |
| 20 | char *index(); |
| 21 | extern int errno; |
| 22 | |
| 23 | main(argc, argv) |
| 24 | char *argv[]; |
| 25 | { |
| 26 | int fd; |
| 27 | FILE *ft, *fp; |
| 28 | char *editor; |
| 29 | |
| 30 | signal(SIGINT, SIG_IGN); |
| 31 | signal(SIGQUIT, SIG_IGN); |
| 32 | signal(SIGHUP, SIG_IGN); |
| 33 | setbuf(stderr, NULL); |
| 34 | fd = open(temp, O_WRONLY|O_CREAT|O_EXCL, 0644); |
| 35 | if (fd < 0) { |
| 36 | if (errno == EEXIST) { |
| 37 | fprintf(stderr, "vipw: password file busy\n"); |
| 38 | exit(1); |
| 39 | } |
| 40 | fprintf(stderr, "vipw: "); perror(temp); |
| 41 | exit(1); |
| 42 | } |
| 43 | ft = fdopen(fd, "w"); |
| 44 | if (ft == NULL) { |
| 45 | fprintf(stderr, "vipw: "); perror(temp); |
| 46 | goto bad; |
| 47 | } |
| 48 | fp = fopen(passwd, "r"); |
| 49 | if (fp == NULL) { |
| 50 | fprintf(stderr, "vipw: "); perror(passwd); |
| 51 | goto bad; |
| 52 | } |
| 53 | while (fgets(buf, sizeof (buf) - 1, fp) != NULL) |
| 54 | fputs(buf, ft); |
| 55 | fclose(ft); fclose(fp); |
| 56 | editor = getenv("EDITOR"); |
| 57 | if (editor == 0) |
| 58 | editor = "vi"; |
| 59 | sprintf(buf, "%s %s", editor, temp); |
| 60 | if (system(buf) == 0) { |
| 61 | struct stat sbuf; |
| 62 | int ok; |
| 63 | |
| 64 | /* sanity checks */ |
| 65 | if (stat(temp, &sbuf) < 0) { |
| 66 | fprintf(stderr, |
| 67 | "vipw: can't stat temp file, %s unchanged\n", |
| 68 | passwd); |
| 69 | goto bad; |
| 70 | } |
| 71 | if (sbuf.st_size == 0) { |
| 72 | fprintf(stderr, "vipw: bad temp file, %s unchanged\n", |
| 73 | passwd); |
| 74 | goto bad; |
| 75 | } |
| 76 | ft = fopen(temp, "r"); |
| 77 | if (ft == NULL) { |
| 78 | fprintf(stderr, |
| 79 | "vipw: can't reopen temp file, %s unchanged\n", |
| 80 | passwd); |
| 81 | goto bad; |
| 82 | } |
| 83 | ok = 0; |
| 84 | while (fgets(buf, sizeof (buf) - 1, ft) != NULL) { |
| 85 | register char *cp; |
| 86 | |
| 87 | cp = index(buf, '\n'); |
| 88 | if (cp == 0) |
| 89 | continue; |
| 90 | *cp = '\0'; |
| 91 | cp = index(buf, ':'); |
| 92 | if (cp == 0) |
| 93 | continue; |
| 94 | *cp = '\0'; |
| 95 | if (strcmp(buf, "root")) |
| 96 | continue; |
| 97 | /* password */ |
| 98 | cp = index(cp + 1, ':'); |
| 99 | if (cp == 0) |
| 100 | break; |
| 101 | /* uid */ |
| 102 | if (atoi(cp + 1) != 0) |
| 103 | break; |
| 104 | cp = index(cp + 1, ':'); |
| 105 | if (cp == 0) |
| 106 | break; |
| 107 | /* gid */ |
| 108 | cp = index(cp + 1, ':'); |
| 109 | if (cp == 0) |
| 110 | break; |
| 111 | /* gecos */ |
| 112 | cp = index(cp + 1, ':'); |
| 113 | if (cp == 0) |
| 114 | break; |
| 115 | /* login directory */ |
| 116 | if (strncmp(++cp, "/:")) |
| 117 | break; |
| 118 | cp += 2; |
| 119 | if (*cp && strcmp(cp, "/bin/sh") && |
| 120 | strcmp(cp, "/bin/csh")) |
| 121 | break; |
| 122 | ok++; |
| 123 | } |
| 124 | fclose(ft); |
| 125 | if (ok) { |
| 126 | if (rename(temp, passwd) < 0) |
| 127 | fprintf(stderr, "vipw: "), perror("rename"); |
| 128 | } else |
| 129 | fprintf(stderr, |
| 130 | "vipw: you mangled the temp file, %s unchanged\n", |
| 131 | passwd); |
| 132 | } |
| 133 | bad: |
| 134 | unlink(temp); |
| 135 | } |