/mandos/release

To get this branch, use:
bzr branch http://bzr.recompile.se/loggerhead/mandos/release
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
#include <stdio.h>	/* popen, fileno */
#include <iso646.h>	/* and, or, not */
#include <sys/types.h>	/* DIR, opendir, stat, struct stat, waitpid,
			   WIFEXITED, WEXITSTATUS, wait */
#include <sys/wait.h>	/* wait */
#include <dirent.h>	/* DIR, opendir */
#include <sys/stat.h>	/* stat, struct stat */
#include <unistd.h>	/* stat, struct stat, chdir */
#include <stdlib.h>	/* EXIT_FAILURE */
#include <sys/select.h>	/* fd_set, select, FD_ZERO, FD_SET, FD_ISSET */
#include <string.h>	/* strlen, strcpy, strcat */
#include <stdbool.h>	/* true */
#include <sys/wait.h>	/* waitpid, WIFEXITED, WEXITSTATUS */
#include <errno.h>	/* errno */

struct process;

typedef struct process{
  pid_t pid;
  int fd;
  char *buffer;
  int buffer_size;
  int buffer_length;
  struct process *next;
} process;

#define BUFFER_SIZE 256

int main(int argc, char *argv[]){
  char plugindir[] = "plugins.d";
  size_t d_name_len, plugindir_len = sizeof(plugindir)-1;
  DIR *dir;
  struct dirent *dirst;
  struct stat st;
  fd_set rfds_orig;
  int ret, maxfd = 0;
  process *process_list = NULL;
  
  dir = opendir(plugindir);

  if(dir == NULL){
    fprintf(stderr, "Can not open directory\n");
    return EXIT_FAILURE;
  }
  
  FD_ZERO(&rfds_orig);
  
  while(true){
    dirst = readdir(dir);
    
    // All directory entries have been processed
    if(dirst == NULL){
      break;
    }
    
    d_name_len = strlen(dirst->d_name);
    
    // Ignore dotfiles and backup files
    if (dirst->d_name[0] == '.'
	or dirst->d_name[d_name_len - 1] == '~'){
      continue;
    }

    char *filename = malloc(d_name_len + plugindir_len + 2);
    strcpy(filename, plugindir);
    strcat(filename, "/");
    strcat(filename, dirst->d_name);    

    stat(filename, &st);

    if (S_ISREG(st.st_mode) and (access(filename, X_OK) == 0)){
      // Starting a new process to be watched
      process *new_process = malloc(sizeof(process));
      int pipefd[2];
      pipe(pipefd);
      new_process->pid = fork();
      if(new_process->pid == 0){
	/* this is the child process */
	closedir(dir);
	close(pipefd[0]);	/* close unused read end of pipe */
	dup2(pipefd[1], STDOUT_FILENO); /* replace our stdout */
	/* create a new modified argument list */
	char **new_argv = malloc(sizeof(char *) * (argc + 1));
	new_argv[0] = filename;
	for(int i = 1; i < argc; i++){
	  new_argv[i] = argv[i];
	}
	new_argv[argc] = NULL;
	if(execv(filename, new_argv) < 0){
	  perror(argv[0]);
	  close(pipefd[1]);
	  exit(EXIT_FAILURE);
	}
	/* no return */
      }
      close(pipefd[1]);		/* close unused write end of pipe */
      new_process->fd = pipefd[0];
      new_process->buffer = malloc(BUFFER_SIZE);
      if (new_process->buffer == NULL){
	perror(argv[0]);
	goto end;
      }
      new_process->buffer_size = BUFFER_SIZE;
      new_process->buffer_length = 0;
      FD_SET(new_process->fd, &rfds_orig);
      
      if (maxfd < new_process->fd){
	maxfd = new_process->fd;
      }
      
      //List handling
      new_process->next = process_list;
      process_list = new_process;
    }
  }
  
  closedir(dir);
  
  if (process_list != NULL){
    while(true){
      fd_set rfds = rfds_orig;
      int select_ret = select(maxfd+1, &rfds, NULL, NULL, NULL);
      if (select_ret == -1){
	perror(argv[0]);
	goto end;
      }else{	
	for(process *process_itr = process_list; process_itr != NULL;
	    process_itr = process_itr->next){
	  if(FD_ISSET(process_itr->fd, &rfds)){
	    if(process_itr->buffer_length + BUFFER_SIZE
	       > process_itr->buffer_size){
		process_itr->buffer = realloc(process_itr->buffer,
					      process_itr->buffer_size
					      + BUFFER_SIZE);
		if (process_itr->buffer == NULL){
		  perror(argv[0]);
		  goto end;
		}
		process_itr->buffer_size += BUFFER_SIZE;
	    }
	    ret = read(process_itr->fd, process_itr->buffer
		       + process_itr->buffer_length, BUFFER_SIZE);
	    process_itr->buffer_length+=ret;
	    if(ret == 0){
	      /* got EOF */
	      /* wait for process exit */
	      int status;
	      waitpid(process_itr->pid, &status, 0);
	      if(WIFEXITED(status) and WEXITSTATUS(status) == 0){
		write(STDOUT_FILENO, process_itr->buffer,
		      process_itr->buffer_length);
		goto end;
	      } else {
		FD_CLR(process_itr->fd, &rfds_orig);
	      }
	    }
	  }
	}
      }
    }
  }
  
 end:
  for(process *process_itr = process_list; process_itr != NULL;
      process_itr = process_itr->next){
    close(process_itr->fd);
    kill(process_itr->pid, SIGTERM);
    free(process_itr->buffer);
  }
  
  while(true){
    int status;
    ret = wait(&status);
    if (ret == -1){
      if(errno != ECHILD){
	perror("wait");
      }
      break;
    }
  }  
  return EXIT_SUCCESS;
}