2 * Copyright (c) 1997 Adrian Sun (asun@zoology.washington.edu)
3 * All rights reserved. See COPYRIGHT.
6 * handle inserting, removing, and freeing of children.
7 * this does it via a hash table. it incurs some overhead over
8 * a linear append/remove in total removal and kills, but it makes
9 * single-entry removals a fast operation. as total removals occur during
10 * child initialization and kills during server shutdown, this is
11 * probably a win for a lot of connections and unimportant for a small
12 * number of connections.
17 #endif /* HAVE_CONFIG_H */
24 #include <sys/types.h>
28 #include <atalk/logger.h>
29 #include <atalk/errchk.h>
30 #include <atalk/util.h>
31 #include <atalk/server_child.h>
34 #define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
35 #endif /* ! WEXITSTATUS */
37 #define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
38 #endif /* ! WIFEXITED */
40 #define WIFSTOPPED(status) (((status) & 0xff) == 0x7f)
43 #define WIFSIGNALED(status) (!WIFSTOPPED(status) && !WIFEXITED(status))
46 #define WTERMSIG(status) ((status) & 0x7f)
49 /* hash/child functions: hash OR's pid */
50 #define CHILD_HASHSIZE 32
51 #define HASH(i) ((((i) >> 8) ^ (i)) & (CHILD_HASHSIZE - 1))
53 typedef struct server_child_fork {
54 struct server_child_data *table[CHILD_HASHSIZE];
55 void (*cleanup)(const pid_t);
58 static inline void hash_child(struct server_child_data **htable,
59 struct server_child_data *child)
61 struct server_child_data **table;
63 table = &htable[HASH(child->pid)];
64 if ((child->next = *table) != NULL)
65 (*table)->prevp = &child->next;
70 static inline void unhash_child(struct server_child_data *child)
74 child->next->prevp = child->prevp;
75 *(child->prevp) = child->next;
79 static struct server_child_data *resolve_child(struct server_child_data **table, pid_t pid)
81 struct server_child_data *child;
83 for (child = table[HASH(pid)]; child; child = child->next) {
84 if (child->pid == pid)
91 /* initialize server_child structure */
92 server_child *server_child_alloc(const int connections, const int nforks)
94 server_child *children;
96 children = (server_child *) calloc(1, sizeof(server_child));
100 children->nsessions = connections;
101 children->nforks = nforks;
102 children->fork = (void *) calloc(nforks, sizeof(server_child_fork));
104 if (!children->fork) {
114 * @return pointer to struct server_child_data on success, NULL on error
116 afp_child_t *server_child_add(server_child *children, int forkid, pid_t pid, int ipc_fd)
118 server_child_fork *fork;
119 afp_child_t *child = NULL;
120 sigset_t sig, oldsig;
122 /* we need to prevent deletions from occuring before we get a
123 * chance to add the child in. */
125 sigaddset(&sig, SIGCHLD);
126 pthread_sigmask(SIG_BLOCK, &sig, &oldsig);
128 /* it's possible that the child could have already died before the
129 * pthread_sigmask. we need to check for this. */
130 if (kill(pid, 0) < 0) {
131 LOG(log_error, logtype_default, "server_child_add: no such process pid [%d]", pid);
135 fork = (server_child_fork *) children->fork + forkid;
137 /* if we already have an entry. just return. */
138 if (child = resolve_child(fork->table, pid))
141 if ((child = calloc(1, sizeof(afp_child_t))) == NULL)
147 child->ipc_fd = ipc_fd;
149 hash_child(fork->table, child);
153 pthread_sigmask(SIG_SETMASK, &oldsig, NULL);
157 /* remove a child and free it */
158 int server_child_remove(server_child *children, const int forkid, pid_t pid)
161 server_child_fork *fork;
162 struct server_child_data *child;
164 fork = (server_child_fork *) children->fork + forkid;
165 if (!(child = resolve_child(fork->table, pid)))
169 if (child->clientid) {
170 free(child->clientid);
171 child->clientid = NULL;
174 /* In main:child_handler() we need the fd in order to remove it from the pollfd set */
188 /* free everything: by using a hash table, this increases the cost of
189 * this part over a linked list by the size of the hash table */
190 void server_child_free(server_child *children)
192 server_child_fork *fork;
193 struct server_child_data *child, *tmp;
196 for (i = 0; i < children->nforks; i++) {
197 fork = (server_child_fork *) children->fork + i;
198 for (j = 0; j < CHILD_HASHSIZE; j++) {
199 child = fork->table[j]; /* start at the beginning */
202 close(child->ipc_fd);
203 if (child->clientid) {
204 free(child->clientid);
211 free(children->fork);
215 /* send signal to all child processes */
216 void server_child_kill(server_child *children, int forkid, int sig)
218 server_child_fork *fork;
219 struct server_child_data *child, *tmp;
222 fork = (server_child_fork *) children->fork + forkid;
223 for (i = 0; i < CHILD_HASHSIZE; i++) {
224 child = fork->table[i];
227 kill(child->pid, sig);
233 /* send kill to a child processes.
234 * a plain-old linked list
235 * FIXME use resolve_child ?
237 static int kill_child(struct server_child_data *child)
239 if (!child->killed) {
240 kill(child->pid, SIGTERM);
241 /* we don't wait because there's no guarantee that we can really kill it */
245 LOG(log_info, logtype_default, "Unresponsive child[%d], sending SIGKILL", child->pid);
246 kill(child->pid, SIGKILL);
252 * Try to find an old session and pass socket
253 * @returns -1 on error, 0 if no matching session was found, 1 if session was found and socket passed
255 int server_child_transfer_session(server_child *children,
260 uint16_t DSI_requestID)
263 server_child_fork *fork;
264 struct server_child_data *child;
267 fork = (server_child_fork *) children->fork + forkid;
268 if ((child = resolve_child(fork->table, pid)) == NULL) {
269 LOG(log_note, logtype_default, "Reconnect: no child[%u]", pid);
270 if (kill(pid, 0) == 0) {
271 LOG(log_note, logtype_default, "Reconnect: terminating old session[%u]", pid);
274 if (kill(pid, 0) == 0) {
275 LOG(log_error, logtype_default, "Reconnect: killing old session[%u]", pid);
284 /* hmm, client 'guess' the pid, rogue? */
285 LOG(log_error, logtype_default, "Reconnect: invalidated child[%u]", pid);
287 } else if (child->uid != uid) {
288 LOG(log_error, logtype_default, "Reconnect: child[%u] not the same user", pid);
292 LOG(log_note, logtype_default, "Reconnect: transfering session to child[%u]", pid);
294 if (writet(child->ipc_fd, &DSI_requestID, 2, 0, 2) != 2) {
295 LOG(log_error, logtype_default, "Reconnect: error sending DSI id to child[%u]", pid);
299 EC_ZERO_LOG(send_fd(child->ipc_fd, afp_socket));
300 EC_ZERO_LOG(kill(pid, SIGURG));
309 /* see if there is a process for the same mac */
310 /* if the times don't match mac has been rebooted */
311 void server_child_kill_one_by_id(server_child *children, int forkid, pid_t pid,
312 uid_t uid, uint32_t idlen, char *id, uint32_t boottime)
314 server_child_fork *fork;
315 struct server_child_data *child, *tmp;
318 fork = (server_child_fork *)children->fork + forkid;
320 for (i = 0; i < CHILD_HASHSIZE; i++) {
321 child = fork->table[i];
324 if ( child->pid != pid) {
325 if (child->idlen == idlen && memcmp(child->clientid, id, idlen) == 0) {
326 if ( child->time != boottime ) {
327 /* Client rebooted */
328 if (uid == child->uid) {
330 LOG(log_warning, logtype_default,
331 "Terminated disconnected child[%u], client rebooted.",
334 LOG(log_warning, logtype_default,
335 "Session with different pid[%u]", child->pid);
338 /* One client with multiple sessions */
339 LOG(log_debug, logtype_default,
340 "Found another session[%u] for client[%u]", child->pid, pid);
344 /* update childs own slot */
345 child->time = boottime;
347 free(child->clientid);
348 LOG(log_debug, logtype_default, "Setting client ID for %u", child->pid);
351 child->idlen = idlen;
352 child->clientid = id;
359 /* for extra cleanup if necessary */
360 void server_child_setup(server_child *children, const int forkid,
361 void (*fcn)(const pid_t))
363 server_child_fork *fork;
365 fork = (server_child_fork *) children->fork + forkid;
370 /* ---------------------------
371 * reset children signals
373 void server_reset_signal(void)
377 const struct itimerval none = {{0, 0}, {0, 0}};
379 setitimer(ITIMER_REAL, &none, NULL);
380 memset(&sv, 0, sizeof(sv));
381 sv.sa_handler = SIG_DFL;
382 sigemptyset( &sv.sa_mask );
384 sigaction(SIGALRM, &sv, NULL );
385 sigaction(SIGHUP, &sv, NULL );
386 sigaction(SIGTERM, &sv, NULL );
387 sigaction(SIGUSR1, &sv, NULL );
388 sigaction(SIGCHLD, &sv, NULL );
391 sigaddset(&sigs, SIGALRM);
392 sigaddset(&sigs, SIGHUP);
393 sigaddset(&sigs, SIGUSR1);
394 sigaddset(&sigs, SIGCHLD);
395 pthread_sigmask(SIG_UNBLOCK, &sigs, NULL);