1 /*
2 * Copyright 2017-2019 the Pacemaker project contributors
3 *
4 * The version control history for this file may have further details.
5 *
6 * This source code is licensed under the GNU Lesser General Public License
7 * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
8 */
9
10 #include <crm_internal.h>
11
12 #include <stdio.h>
13 #include <ctype.h>
14 #include <stdlib.h>
15 #include <signal.h>
16 #include <unistd.h>
17 #include <sys/types.h>
18 #include <sys/wait.h>
19
20 #include <crm/crm.h>
21 #include "lrmd_private.h"
22
23 static pid_t main_pid = 0;
24
25 static void
sigdone(void)26 sigdone(void)
27 {
28 exit(0);
29 }
30
31 static void
sigreap(void)32 sigreap(void)
33 {
34 pid_t pid = 0;
35 int status;
36
37 do {
38 /*
39 * Opinions seem to differ as to what to put here:
40 * -1, any child process
41 * 0, any child process whose process group ID is equal to that of the calling process
42 */
43 pid = waitpid(-1, &status, WNOHANG);
44 if (pid == main_pid) {
45 /* Exit when pacemaker-remote exits and use the same return code */
46 if (WIFEXITED(status)) {
47 exit(WEXITSTATUS(status));
48 }
49 exit(1);
50 }
51 } while (pid > 0);
52 }
53
54 static struct {
55 int sig;
56 void (*handler)(void);
57 } sigmap[] = {
58 { SIGCHLD, sigreap },
59 { SIGINT, sigdone },
60 };
61
62 /*!
63 * \internal
64 * \brief Check a line of text for a valid environment variable name
65 *
66 * \param[in] line Text to check
67 * \param[out] first First character of valid name if found, NULL otherwise
68 * \param[out] last Last character of valid name if found, NULL otherwise
69 *
70 * \return TRUE if valid name found, FALSE otherwise
71 * \note It's reasonable to impose limitations on environment variable names
72 * beyond what C or setenv() does: We only allow names that contain only
73 * [a-zA-Z0-9_] characters and do not start with a digit.
74 */
75 static bool
find_env_var_name(char * line,char ** first,char ** last)76 find_env_var_name(char *line, char **first, char **last)
77 {
78 // Skip leading whitespace
79 *first = line;
80 while (isspace(**first)) {
81 ++*first;
82 }
83
84 if (isalpha(**first) || (**first == '_')) { // Valid first character
85 *last = *first;
86 while (isalnum(*(*last + 1)) || (*(*last + 1) == '_')) {
87 ++*last;
88 }
89 return TRUE;
90 }
91
92 *first = *last = NULL;
93 return FALSE;
94 }
95
96 static void
load_env_vars(const char * filename)97 load_env_vars(const char *filename)
98 {
99 /* We haven't forked or initialized logging yet, so don't leave any file
100 * descriptors open, and don't log -- silently ignore errors.
101 */
102 FILE *fp = fopen(filename, "r");
103
104 if (fp != NULL) {
105 char line[LINE_MAX] = { '\0', };
106
107 while (fgets(line, LINE_MAX, fp) != NULL) {
108 char *name = NULL;
109 char *end = NULL;
110 char *value = NULL;
111 char *quote = NULL;
112
113 // Look for valid name immediately followed by equals sign
114 if (find_env_var_name(line, &name, &end) && (*++end == '=')) {
115
116 // Null-terminate name, and advance beyond equals sign
117 *end++ = '\0';
118
119 // Check whether value is quoted
120 if ((*end == '\'') || (*end == '"')) {
121 quote = end++;
122 }
123 value = end;
124
125 if (quote) {
126 /* Value is remaining characters up to next non-backslashed
127 * matching quote character.
128 */
129 while (((*end != *quote) || (*(end - 1) == '\\'))
130 && (*end != '\0')) {
131 end++;
132 }
133 if (*end == *quote) {
134 // Null-terminate value, and advance beyond close quote
135 *end++ = '\0';
136 } else {
137 // Matching closing quote wasn't found
138 value = NULL;
139 }
140
141 } else {
142 /* Value is remaining characters up to next non-backslashed
143 * whitespace.
144 */
145 while ((!isspace(*end) || (*(end - 1) == '\\'))
146 && (*end != '\0')) {
147 ++end;
148 }
149
150 if (end == (line + LINE_MAX - 1)) {
151 // Line was too long
152 value = NULL;
153 }
154 // Do NOT null-terminate value (yet)
155 }
156
157 /* We have a valid name and value, and end is now the character
158 * after the closing quote or the first whitespace after the
159 * unquoted value. Make sure the rest of the line is just
160 * whitespace or a comment.
161 */
162 if (value) {
163 char *value_end = end;
164
165 while (isspace(*end) && (*end != '\n')) {
166 ++end;
167 }
168 if ((*end == '\n') || (*end == '#')) {
169 if (quote == NULL) {
170 // Now we can null-terminate an unquoted value
171 *value_end = '\0';
172 }
173
174 // Don't overwrite (bundle options take precedence)
175 setenv(name, value, 0);
176
177 } else {
178 value = NULL;
179 }
180 }
181 }
182
183 if ((value == NULL) && (strchr(line, '\n') == NULL)) {
184 // Eat remainder of line beyond LINE_MAX
185 if (fscanf(fp, "%*[^\n]\n") == EOF) {
186 value = NULL; // Don't care, make compiler happy
187 }
188 }
189 }
190 fclose(fp);
191 }
192 }
193
194 void
remoted_spawn_pidone(int argc,char ** argv,char ** envp)195 remoted_spawn_pidone(int argc, char **argv, char **envp)
196 {
197 sigset_t set;
198
199 /* This environment variable exists for two purposes:
200 * - For testing, setting it to "full" enables full PID 1 behavior even
201 * when PID is not 1
202 * - Setting to "vars" enables just the loading of environment variables
203 * from /etc/pacemaker/pcmk-init.env, which could be useful for testing or
204 * containers with a custom PID 1 script that launches pacemaker-remoted.
205 */
206 const char *pid1 = (getpid() == 1)? "full" : getenv("PCMK_remote_pid1");
207
208 if (pid1 == NULL) {
209 return;
210 }
211
212 /* When a container is launched, it may be given specific environment
213 * variables, which for Pacemaker bundles are given in the bundle
214 * configuration. However, that does not allow for host-specific values.
215 * To allow for that, look for a special file containing a shell-like syntax
216 * of name/value pairs, and export those into the environment.
217 */
218 load_env_vars("/etc/pacemaker/pcmk-init.env");
219
220 if (strcmp(pid1, "full")) {
221 return;
222 }
223
224 sigfillset(&set);
225 sigprocmask(SIG_BLOCK, &set, 0);
226
227 main_pid = fork();
228 switch (main_pid) {
229 case 0:
230 sigprocmask(SIG_UNBLOCK, &set, NULL);
231 setsid();
232 setpgid(0, 0);
233
234 // Child remains as pacemaker_remoted
235 return;
236 case -1:
237 perror("fork");
238 }
239
240 /* Parent becomes the reaper of zombie processes */
241 /* Safe to initialize logging now if needed */
242
243 # ifdef HAVE___PROGNAME
244 /* Differentiate ourselves in the 'ps' output */
245 {
246 char *p;
247 int i, maxlen;
248 char *LastArgv = NULL;
249 const char *name = "pcmk-init";
250
251 for (i = 0; i < argc; i++) {
252 if (!i || (LastArgv + 1 == argv[i]))
253 LastArgv = argv[i] + strlen(argv[i]);
254 }
255
256 for (i = 0; envp[i] != NULL; i++) {
257 if ((LastArgv + 1) == envp[i]) {
258 LastArgv = envp[i] + strlen(envp[i]);
259 }
260 }
261
262 maxlen = (LastArgv - argv[0]) - 2;
263
264 i = strlen(name);
265
266 /* We can overwrite individual argv[] arguments */
267 snprintf(argv[0], maxlen, "%s", name);
268
269 /* Now zero out everything else */
270 p = &argv[0][i];
271 while (p < LastArgv) {
272 *p++ = '\0';
273 }
274 argv[1] = NULL;
275 }
276 # endif // HAVE___PROGNAME
277
278 while (1) {
279 int sig;
280 size_t i;
281
282 sigwait(&set, &sig);
283 for (i = 0; i < DIMOF(sigmap); i++) {
284 if (sigmap[i].sig == sig) {
285 sigmap[i].handler();
286 break;
287 }
288 }
289 }
290 }
291