| 1 | |
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| 2 | /* |
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| 3 | * context_save.c -- write out the updated context file |
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| 4 | * |
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| 5 | * $Id: context_save.c,v 1.1.1.1 1999-02-07 18:14:07 danw Exp $ |
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| 6 | */ |
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| 7 | |
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| 8 | #include <h/mh.h> |
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| 9 | #include <h/signals.h> |
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| 10 | |
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| 11 | /* |
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| 12 | * static prototypes |
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| 13 | */ |
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| 14 | static int m_chkids(void); |
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| 15 | |
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| 16 | |
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| 17 | void |
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| 18 | context_save (void) |
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| 19 | { |
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| 20 | int action; |
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| 21 | register struct node *np; |
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| 22 | FILE *out; |
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| 23 | sigset_t set, oset; |
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| 24 | |
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| 25 | if (!(ctxflags & CTXMOD)) |
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| 26 | return; |
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| 27 | ctxflags &= ~CTXMOD; |
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| 28 | |
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| 29 | if ((action = m_chkids ()) > 0) |
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| 30 | return; /* child did it for us */ |
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| 31 | |
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| 32 | /* block a few signals */ |
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| 33 | sigemptyset (&set); |
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| 34 | sigaddset (&set, SIGHUP); |
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| 35 | sigaddset (&set, SIGINT); |
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| 36 | sigaddset (&set, SIGQUIT); |
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| 37 | sigaddset (&set, SIGTERM); |
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| 38 | SIGPROCMASK (SIG_BLOCK, &set, &oset); |
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| 39 | |
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| 40 | if (!(out = fopen (ctxpath, "w"))) |
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| 41 | adios (ctxpath, "unable to write"); |
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| 42 | for (np = m_defs; np; np = np->n_next) |
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| 43 | if (np->n_context) |
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| 44 | fprintf (out, "%s: %s\n", np->n_name, np->n_field); |
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| 45 | fclose (out); |
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| 46 | |
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| 47 | SIGPROCMASK (SIG_SETMASK, &oset, &set); /* reset the signal mask */ |
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| 48 | |
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| 49 | if (action == 0) |
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| 50 | _exit (0); /* we are child, time to die */ |
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| 51 | } |
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| 52 | |
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| 53 | /* |
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| 54 | * This hack brought to you so we can handle set[ug]id MH programs. |
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| 55 | * If we return -1, then no fork is made, we update .mh_profile |
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| 56 | * normally, and return to the caller normally. If we return 0, |
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| 57 | * then the child is executing, .mh_profile is modified after |
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| 58 | * we set our [ug]ids to the norm. If we return > 0, then the |
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| 59 | * parent is executed and .mh_profile has already be modified. |
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| 60 | * We can just return to the caller immediately. |
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| 61 | */ |
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| 62 | |
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| 63 | static int |
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| 64 | m_chkids (void) |
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| 65 | { |
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| 66 | int i; |
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| 67 | pid_t pid; |
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| 68 | |
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| 69 | if (getuid () == geteuid ()) |
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| 70 | return (-1); |
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| 71 | |
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| 72 | for (i = 0; (pid = fork ()) == -1 && i < 5; i++) |
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| 73 | sleep (5); |
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| 74 | |
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| 75 | switch (pid) { |
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| 76 | case -1: |
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| 77 | break; |
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| 78 | |
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| 79 | case 0: |
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| 80 | setgid (getgid ()); |
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| 81 | setuid (getuid ()); |
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| 82 | break; |
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| 83 | |
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| 84 | default: |
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| 85 | pidwait (pid, -1); |
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| 86 | break; |
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| 87 | } |
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| 88 | |
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| 89 | return pid; |
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| 90 | } |
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