1 | #include "filterproc.h" |
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2 | #include <sys/wait.h> |
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3 | #include <fcntl.h> |
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4 | #include <glib.h> |
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5 | #include <poll.h> |
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6 | #include <string.h> |
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7 | #include <unistd.h> |
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8 | |
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9 | /* Even in case of error, send_receive is responsible for closing wfd |
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10 | * (to EOF the child) and rfd (for consistency). */ |
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11 | static int send_receive(int rfd, int wfd, const char *out, char **in) |
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12 | { |
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13 | GString *str = g_string_new(""); |
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14 | char buf[1024]; |
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15 | nfds_t nfds; |
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16 | int err = 0; |
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17 | struct pollfd fds[2]; |
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18 | |
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19 | fcntl(rfd, F_SETFL, O_NONBLOCK | fcntl(rfd, F_GETFL)); |
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20 | fcntl(wfd, F_SETFL, O_NONBLOCK | fcntl(wfd, F_GETFL)); |
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21 | |
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22 | fds[0].fd = rfd; |
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23 | fds[0].events = POLLIN; |
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24 | fds[1].fd = wfd; |
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25 | fds[1].events = POLLOUT; |
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26 | |
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27 | if(!out || !*out) { |
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28 | /* Nothing to write. Close our end so the child doesn't hang waiting. */ |
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29 | close(wfd); wfd = -1; |
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30 | out = NULL; |
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31 | } |
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32 | |
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33 | while(1) { |
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34 | if(out && *out) { |
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35 | nfds = 2; |
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36 | } else { |
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37 | nfds = 1; |
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38 | } |
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39 | err = poll(fds, nfds, -1); |
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40 | if(err < 0) { |
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41 | break; |
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42 | } |
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43 | if(out && *out) { |
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44 | if(fds[1].revents & POLLOUT) { |
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45 | err = write(wfd, out, strlen(out)); |
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46 | if(err > 0) { |
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47 | out += err; |
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48 | } |
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49 | if(err < 0) { |
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50 | out = NULL; |
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51 | } |
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52 | } |
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53 | if(!out || !*out || fds[1].revents & (POLLERR | POLLHUP)) { |
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54 | close(wfd); wfd = -1; |
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55 | out = NULL; |
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56 | } |
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57 | } |
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58 | if(fds[0].revents & POLLIN) { |
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59 | err = read(rfd, buf, sizeof(buf)); |
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60 | if(err <= 0) { |
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61 | break; |
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62 | } |
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63 | g_string_append_len(str, buf, err); |
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64 | } else if(fds[0].revents & (POLLHUP | POLLERR)) { |
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65 | err = 0; |
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66 | break; |
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67 | } |
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68 | } |
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69 | |
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70 | if (wfd >= 0) close(wfd); |
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71 | close(rfd); |
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72 | *in = g_string_free(str, err < 0); |
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73 | return err; |
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74 | } |
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75 | |
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76 | int call_filter(const char *const *argv, const char *in, char **out, int *status) |
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77 | { |
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78 | int err; |
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79 | GPid child_pid; |
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80 | int child_stdin, child_stdout; |
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81 | |
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82 | if (!g_spawn_async_with_pipes(NULL, (char**)argv, NULL, |
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83 | G_SPAWN_SEARCH_PATH | G_SPAWN_DO_NOT_REAP_CHILD, |
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84 | NULL, NULL, |
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85 | &child_pid, &child_stdin, &child_stdout, NULL, |
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86 | NULL)) { |
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87 | *out = NULL; |
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88 | return 1; |
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89 | } |
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90 | |
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91 | err = send_receive(child_stdout, child_stdin, in, out); |
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92 | if (err == 0) { |
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93 | waitpid(child_pid, status, 0); |
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94 | } |
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95 | return err; |
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96 | } |
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