[359] | 1 | |
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| 2 | /* |
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| 3 | * cronload.real.c |
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| 4 | * |
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| 5 | * CRONTAB |
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| 6 | * |
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| 7 | * usually setuid root, -c option only works if getuid() == geteuid() |
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| 8 | * |
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| 9 | * Copyright 1994 Matthew Dillon (dillon@apollo.backplane.com) |
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| 10 | * May be distributed under the GNU General Public License |
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| 11 | */ |
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| 12 | |
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| 13 | #include "defs.h" |
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| 14 | |
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| 15 | #define VERSION "$Revision: 359 $" |
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| 16 | |
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| 17 | const char *CDir = SCRIPTS_CRONTABS; |
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| 18 | int UserId; |
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| 19 | short LogLevel = 9; |
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| 20 | |
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| 21 | int GetReplaceStream(const char *user, const char *file); |
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| 22 | extern int ChangeUser(const char *user, short dochdir); |
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| 23 | |
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| 24 | int |
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| 25 | main(int ac, char **av) |
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| 26 | { |
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| 27 | enum { NONE, LIST, REPLACE, DELETE } option = NONE; |
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| 28 | struct passwd *pas; |
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| 29 | char *repFile = NULL; |
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| 30 | int repFd = 0; |
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| 31 | int i; |
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| 32 | char caller[256]; /* user that ran program */ |
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| 33 | |
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| 34 | UserId = getuid(); |
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| 35 | if ((pas = getpwuid(UserId)) == NULL) { |
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| 36 | perror("getpwuid"); |
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| 37 | exit(1); |
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| 38 | } |
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| 39 | snprintf(caller, sizeof(caller), "%s", pas->pw_name); |
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| 40 | |
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| 41 | i = 1; |
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| 42 | if (ac > 1) { |
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| 43 | if (av[1][0] == '-' && av[1][1] == 0) { |
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| 44 | option = REPLACE; |
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| 45 | ++i; |
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| 46 | } else if (av[1][0] != '-') { |
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| 47 | option = REPLACE; |
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| 48 | ++i; |
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| 49 | repFile = av[1]; |
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| 50 | } |
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| 51 | } |
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| 52 | |
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| 53 | for (; i < ac; ++i) { |
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| 54 | char *ptr = av[i]; |
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| 55 | |
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| 56 | if (*ptr != '-') |
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| 57 | break; |
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| 58 | ptr += 2; |
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| 59 | |
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| 60 | switch(ptr[-1]) { |
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| 61 | case 'l': |
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| 62 | if (ptr[-1] == 'l') |
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| 63 | option = LIST; |
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| 64 | /* fall through */ |
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| 65 | case 'd': |
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| 66 | if (ptr[-1] == 'd') |
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| 67 | option = DELETE; |
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| 68 | /* fall through */ |
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| 69 | case 'u': |
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| 70 | if (i + 1 < ac && av[i+1][0] != '-') { |
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| 71 | ++i; |
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| 72 | if (getuid() == geteuid()) { |
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| 73 | pas = getpwnam(av[i]); |
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| 74 | if (pas) { |
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| 75 | UserId = pas->pw_uid; |
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| 76 | } else { |
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| 77 | errx(1, "user %s unknown\n", av[i]); |
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| 78 | } |
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| 79 | } else { |
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| 80 | errx(1, "only the superuser may specify a user\n"); |
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| 81 | } |
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| 82 | } |
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| 83 | break; |
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| 84 | case 'c': |
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| 85 | if ((getuid() == geteuid()) && (0 == getuid())) { |
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| 86 | CDir = (*ptr) ? ptr : av[++i]; |
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| 87 | } else { |
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| 88 | errx(1, "-c option: superuser only\n"); |
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| 89 | } |
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| 90 | break; |
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| 91 | default: |
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| 92 | i = ac; |
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| 93 | break; |
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| 94 | } |
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| 95 | } |
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| 96 | if (i != ac || option == NONE) { |
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| 97 | printf("cronload.real " VERSION "\n"); |
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| 98 | printf("cronload.real file <opts> replace crontab from file\n"); |
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| 99 | printf("cronload.real - <opts> replace crontab from stdin\n"); |
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| 100 | printf("cronload.real -u user specify user\n"); |
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| 101 | printf("cronload.real -l [user] list crontab for user\n"); |
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| 102 | printf("cronload.real -d [user] delete crontab for user\n"); |
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| 103 | printf("cronload.real -c dir specify crontab directory\n"); |
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| 104 | exit(0); |
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| 105 | } |
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| 106 | |
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| 107 | /* |
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| 108 | * Get password entry |
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| 109 | */ |
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| 110 | |
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| 111 | if ((pas = getpwuid(UserId)) == NULL) { |
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| 112 | perror("getpwuid"); |
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| 113 | exit(1); |
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| 114 | } |
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| 115 | |
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| 116 | /* |
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| 117 | * If there is a replacement file, obtain a secure descriptor to it. |
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| 118 | */ |
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| 119 | |
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| 120 | if (repFile) { |
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| 121 | repFd = GetReplaceStream(caller, repFile); |
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| 122 | if (repFd < 0) { |
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| 123 | errx(1, "unable to read replacement file\n"); |
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| 124 | } |
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| 125 | } |
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| 126 | |
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| 127 | /* |
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| 128 | * Change directory to our crontab directory |
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| 129 | */ |
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| 130 | |
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| 131 | if (chdir(CDir) < 0) { |
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| 132 | errx(1, "cannot change dir to %s: %s\n", CDir, strerror(errno)); |
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| 133 | } |
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| 134 | |
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| 135 | /* |
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| 136 | * Handle options as appropriate |
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| 137 | */ |
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| 138 | |
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| 139 | switch(option) { |
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| 140 | case LIST: |
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| 141 | { |
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| 142 | FILE *fi; |
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| 143 | char buf[1024]; |
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| 144 | |
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| 145 | if ((fi = fopen(pas->pw_name, "r"))) { |
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| 146 | while (fgets(buf, sizeof(buf), fi) != NULL) |
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| 147 | fputs(buf, stdout); |
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| 148 | fclose(fi); |
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| 149 | } else { |
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| 150 | fprintf(stderr, "no crontab for %s\n", pas->pw_name); |
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| 151 | } |
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| 152 | } |
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| 153 | break; |
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| 154 | case REPLACE: |
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| 155 | { |
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| 156 | char buf[1024]; |
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| 157 | char path[1024]; |
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| 158 | int fd; |
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| 159 | int n; |
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| 160 | |
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| 161 | snprintf(path, sizeof(path), "%s.new", pas->pw_name); |
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| 162 | if ((fd = open(path, O_CREAT|O_TRUNC|O_EXCL|O_APPEND|O_WRONLY, 0600)) >= 0) { |
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| 163 | while ((n = read(repFd, buf, sizeof(buf))) > 0) { |
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| 164 | write(fd, buf, n); |
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| 165 | } |
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| 166 | close(fd); |
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| 167 | rename(path, pas->pw_name); |
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| 168 | } else { |
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| 169 | fprintf(stderr, "unable to create %s/%s: %s\n", |
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| 170 | CDir, |
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| 171 | path, |
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| 172 | strerror(errno) |
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| 173 | ); |
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| 174 | } |
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| 175 | close(repFd); |
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| 176 | } |
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| 177 | break; |
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| 178 | case DELETE: |
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| 179 | remove(pas->pw_name); |
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| 180 | break; |
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| 181 | case NONE: |
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| 182 | default: |
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| 183 | break; |
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| 184 | } |
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| 185 | |
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| 186 | /* |
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| 187 | * Bump notification file. Handle window where crond picks file up |
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| 188 | * before we can write our entry out. |
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| 189 | */ |
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| 190 | /* // only applicable to dcron |
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| 191 | if (option == REPLACE || option == DELETE) { |
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| 192 | FILE *fo; |
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| 193 | struct stat st; |
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| 194 | |
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| 195 | while ((fo = fopen(CRONUPDATE, "a"))) { |
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| 196 | fprintf(fo, "%s\n", pas->pw_name); |
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| 197 | fflush(fo); |
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| 198 | if (fstat(fileno(fo), &st) != 0 || st.st_nlink != 0) { |
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| 199 | fclose(fo); |
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| 200 | break; |
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| 201 | } |
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| 202 | fclose(fo); |
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| 203 | // * loop * / |
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| 204 | } |
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| 205 | if (fo == NULL) { |
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| 206 | fprintf(stderr, "unable to append to %s/%s\n", CDir, CRONUPDATE); |
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| 207 | } |
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| 208 | } |
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| 209 | */ |
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| 210 | (volatile void)exit(0); |
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| 211 | /* not reached */ |
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| 212 | } |
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| 213 | |
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| 214 | int |
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| 215 | GetReplaceStream(const char *user, const char *file) |
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| 216 | { |
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| 217 | int filedes[2]; |
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| 218 | int pid; |
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| 219 | int fd; |
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| 220 | int n; |
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| 221 | char buf[1024]; |
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| 222 | |
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| 223 | if (pipe(filedes) < 0) { |
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| 224 | perror("pipe"); |
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| 225 | return(-1); |
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| 226 | } |
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| 227 | if ((pid = fork()) < 0) { |
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| 228 | perror("fork"); |
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| 229 | return(-1); |
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| 230 | } |
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| 231 | if (pid > 0) { |
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| 232 | /* |
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| 233 | * PARENT |
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| 234 | */ |
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| 235 | |
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| 236 | close(filedes[1]); |
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| 237 | if (read(filedes[0], buf, 1) != 1) { |
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| 238 | close(filedes[0]); |
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| 239 | filedes[0] = -1; |
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| 240 | } |
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| 241 | return(filedes[0]); |
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| 242 | } |
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| 243 | |
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| 244 | /* |
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| 245 | * CHILD |
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| 246 | */ |
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| 247 | |
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| 248 | close(filedes[0]); |
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| 249 | |
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| 250 | if (ChangeUser(user, 0) < 0) |
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| 251 | exit(0); |
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| 252 | |
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| 253 | fd = open(file, O_RDONLY); |
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| 254 | if (fd < 0) |
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| 255 | errx(0, "unable to open %s\n", file); |
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| 256 | buf[0] = 0; |
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| 257 | write(filedes[1], buf, 1); |
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| 258 | while ((n = read(fd, buf, sizeof(buf))) > 0) { |
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| 259 | write(filedes[1], buf, n); |
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| 260 | } |
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| 261 | exit(0); |
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| 262 | } |
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