6cecb9cf |
1 | /* lttd |
2 | * |
3 | * Linux Trace Toolkit Daemon |
4 | * |
5 | * This is a simple daemon that reads a few relayfs channels and save them in a |
6 | * trace. |
7 | * |
8 | * |
9 | * Copyright 2005 - |
10 | * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> |
11 | */ |
12 | |
13 | #include <stdio.h> |
14 | #include <errno.h> |
15 | #include <sys/types.h> |
16 | #include <sys/stat.h> |
17 | #include <unistd.h> |
18 | #include <stdlib.h> |
19 | #include <dirent.h> |
20 | #include <string.h> |
21 | |
22 | |
23 | enum { |
24 | GET_SUBBUF, |
25 | PUT_SUBBUF, |
26 | GET_N_BUBBUFS, |
27 | GET_SUBBUF_SIZE |
28 | }; |
29 | |
30 | struct fd_pair { |
31 | int channel; |
32 | int trace; |
33 | }; |
34 | |
35 | struct channel_trace_fd { |
36 | struct fd_pair *pair; |
37 | int num_pairs; |
38 | }; |
39 | |
40 | static char *trace_name = NULL; |
41 | static char *channel_name = NULL; |
42 | static int daemon_mode = 0; |
43 | |
44 | |
45 | /* Args : |
46 | * |
47 | * -t directory Directory name of the trace to write to. Will be created. |
48 | * -c directory Root directory of the relayfs trace channels. |
49 | * -d Run in background (daemon). |
50 | */ |
51 | void show_arguments(void) |
52 | { |
53 | printf("Please use the following arguments :\n"); |
54 | printf("\n"); |
55 | printf("-t directory Directory name of the trace to write to.\n" |
56 | " It will be created.\n"); |
57 | printf("-c directory Root directory of the relayfs trace channels.\n"); |
58 | printf("-d Run in background (daemon).\n"); |
59 | printf("\n"); |
60 | } |
61 | |
62 | |
63 | /* parse_arguments |
64 | * |
65 | * Parses the command line arguments. |
66 | * |
67 | * Returns 1 if the arguments were correct, but doesn't ask for program |
68 | * continuation. Returns -1 if the arguments are incorrect, or 0 if OK. |
69 | */ |
70 | int parse_arguments(int argc, char **argv) |
71 | { |
72 | int ret = 0; |
73 | int argn = 1; |
74 | |
75 | if(argc == 2) { |
76 | if(strcmp(argv[1], "-h") == 0) { |
77 | return 1; |
78 | } |
79 | } |
80 | |
81 | while(argn < argc-1) { |
82 | |
83 | switch(argv[argn][0]) { |
84 | case '-': |
85 | switch(argv[argn][1]) { |
86 | case 't': |
87 | trace_name = argv[argn+1]; |
88 | argn++; |
89 | break; |
90 | case 'c': |
91 | channel_name = argv[argn+1]; |
92 | argn++; |
93 | break; |
94 | case 'd': |
95 | daemon_mode = 1; |
96 | break; |
97 | default: |
98 | printf("Invalid argument '%s'.\n", argv[argn]); |
99 | printf("\n"); |
100 | ret = -1; |
101 | } |
102 | break; |
103 | default: |
104 | printf("Invalid argument '%s'.\n", argv[argn]); |
105 | printf("\n"); |
106 | ret = -1; |
107 | } |
108 | argn++; |
109 | } |
110 | |
111 | if(trace_name == NULL) { |
112 | printf("Please specify a trace name.\n"); |
113 | printf("\n"); |
114 | ret = -1; |
115 | } |
116 | |
117 | if(channel_name == NULL) { |
118 | printf("Please specify a channel name.\n"); |
119 | printf("\n"); |
120 | ret = -1; |
121 | } |
122 | |
123 | return ret; |
124 | } |
125 | |
126 | void show_info(void) |
127 | { |
128 | printf("Linux Trace Toolkit Trace Daemon\n"); |
129 | printf("\n"); |
130 | printf("Reading from relayfs directory : %s\n", channel_name); |
131 | printf("Writing to trace directory : %s\n", trace_name); |
132 | printf("\n"); |
133 | } |
134 | |
135 | |
136 | int open_channel_trace_pairs(char *subchannel_name, char *subtrace_name, |
137 | struct channel_trace_fd *fd_pairs) |
138 | { |
139 | DIR *channel_dir = opendir(subchannel_name); |
140 | struct dirent *entry; |
141 | struct stat stat_buf; |
142 | int ret; |
143 | char path_channel[PATH_MAX]; |
144 | int path_channel_len; |
145 | char *path_channel_ptr; |
146 | char path_trace[PATH_MAX]; |
147 | int path_trace_len; |
148 | char *path_trace_ptr; |
149 | |
150 | if(channel_dir == NULL) { |
151 | perror(subchannel_name); |
152 | return ENOENT; |
153 | } |
154 | |
155 | //FIXME : check if the directory already exist, and ask the user if he wants |
156 | //to append to the traces. |
157 | printf("Creating trace subdirectory %s\n", subtrace_name); |
158 | ret = mkdir(subtrace_name, S_IRWXU|S_IRWXG|S_IRWXO); |
159 | if(ret == -1) { |
160 | perror(subtrace_name); |
161 | return -1; |
162 | } |
163 | |
164 | strncpy(path_channel, subchannel_name, PATH_MAX-1); |
165 | path_channel_len = strlen(path_channel); |
166 | path_channel[path_channel_len] = '/'; |
167 | path_channel_len++; |
168 | path_channel_ptr = path_channel + path_channel_len; |
169 | |
170 | strncpy(path_trace, subtrace_name, PATH_MAX-1); |
171 | path_trace_len = strlen(path_trace); |
172 | path_trace[path_trace_len] = '/'; |
173 | path_trace_len++; |
174 | path_trace_ptr = path_trace + path_trace_len; |
175 | |
176 | while((entry = readdir(channel_dir)) != NULL) { |
177 | |
178 | if(entry->d_name[0] == '.') continue; |
179 | |
180 | strncpy(path_channel_ptr, entry->d_name, PATH_MAX - path_channel_len); |
181 | strncpy(path_trace_ptr, entry->d_name, PATH_MAX - path_trace_len); |
182 | |
183 | ret = stat(path_channel, &stat_buf); |
184 | if(ret == -1) { |
185 | perror(path_channel); |
186 | continue; |
187 | } |
188 | |
189 | printf("Channel file : %s\n", path_channel); |
190 | |
191 | if(S_ISDIR(stat_buf.st_mode)) { |
192 | |
193 | printf("Entering channel subdirectory...\n"); |
194 | ret = open_channel_trace_pairs(path_channel, path_trace, fd_pairs); |
195 | if(ret < 0) continue; |
196 | } |
197 | |
198 | } |
199 | |
200 | closedir(channel_dir); |
201 | |
202 | return 0; |
203 | } |
204 | |
205 | |
206 | int read_channels(struct channel_trace_fd *fd_pairs) |
207 | { |
208 | return 0; |
209 | } |
210 | |
211 | |
212 | void close_channel_trace_pairs(struct channel_trace_fd *fd_pairs) |
213 | { |
214 | |
215 | } |
216 | |
217 | int main(int argc, char ** argv) |
218 | { |
219 | int ret; |
220 | pid_t pid; |
221 | struct channel_trace_fd fd_pairs = { NULL, 0 }; |
222 | |
223 | ret = parse_arguments(argc, argv); |
224 | |
225 | if(ret != 0) show_arguments(); |
226 | if(ret < 0) return EINVAL; |
227 | if(ret > 0) return 0; |
228 | |
229 | show_info(); |
230 | |
231 | if(daemon_mode) { |
232 | pid = fork(); |
233 | |
234 | if(pid > 0) { |
235 | /* parent */ |
236 | return 0; |
237 | } else if(pid < 0) { |
238 | /* error */ |
239 | printf("An error occured while forking.\n"); |
240 | return -1; |
241 | } |
242 | /* else, we are the child, continue... */ |
243 | } |
244 | |
245 | if(ret = open_channel_trace_pairs(channel_name, trace_name, &fd_pairs)) |
246 | goto end_main; |
247 | |
248 | ret = read_channels(&fd_pairs); |
249 | |
250 | close_channel_trace_pairs(&fd_pairs); |
251 | |
252 | end_main: |
253 | |
254 | return ret; |
255 | } |