s3:net_util: add some const to sockaddr_storage
[Samba/gebeck_regimport.git] / lib / tdb2 / test / external-agent.c
blob055b5de736f6f04334fd990dc2409d1630650ff6
1 #include "external-agent.h"
2 #include "logging.h"
3 #include "lock-tracking.h"
4 #include <sys/types.h>
5 #include <sys/wait.h>
6 #include <unistd.h>
7 #include <err.h>
8 #include <fcntl.h>
9 #include <stdlib.h>
10 #include <limits.h>
11 #include <string.h>
12 #include <errno.h>
13 #include <ccan/tdb2/private.h>
14 #include <ccan/tap/tap.h>
15 #include <stdio.h>
16 #include <stdarg.h>
18 static struct tdb_context *tdb;
20 static enum TDB_ERROR clear_if_first(int fd, void *arg)
22 /* We hold a lock offset 63 always, so we can tell if anyone is holding it. */
23 struct flock fl;
25 fl.l_type = F_WRLCK;
26 fl.l_whence = SEEK_SET;
27 fl.l_start = 63;
28 fl.l_len = 1;
30 if (fcntl(fd, F_SETLK, &fl) == 0) {
31 /* We must be first ones to open it! */
32 diag("agent truncating file!");
33 if (ftruncate(fd, 0) != 0) {
34 return TDB_ERR_IO;
37 fl.l_type = F_RDLCK;
38 if (fcntl(fd, F_SETLKW, &fl) != 0) {
39 return TDB_ERR_IO;
41 return TDB_SUCCESS;
44 static enum agent_return do_operation(enum operation op, const char *name)
46 TDB_DATA k;
47 enum agent_return ret;
48 TDB_DATA data;
49 enum TDB_ERROR ecode;
50 union tdb_attribute cif;
52 if (op != OPEN && op != OPEN_WITH_HOOK && !tdb) {
53 diag("external: No tdb open!");
54 return OTHER_FAILURE;
57 diag("external: %s", operation_name(op));
59 k = tdb_mkdata(name, strlen(name));
61 locking_would_block = 0;
62 switch (op) {
63 case OPEN:
64 if (tdb) {
65 diag("Already have tdb %s open", tdb->name);
66 return OTHER_FAILURE;
68 tdb = tdb_open(name, TDB_DEFAULT, O_RDWR, 0, &tap_log_attr);
69 if (!tdb) {
70 if (!locking_would_block)
71 diag("Opening tdb gave %s", strerror(errno));
72 forget_locking();
73 ret = OTHER_FAILURE;
74 } else
75 ret = SUCCESS;
76 break;
77 case OPEN_WITH_HOOK:
78 if (tdb) {
79 diag("Already have tdb %s open", tdb->name);
80 return OTHER_FAILURE;
82 cif.openhook.base.attr = TDB_ATTRIBUTE_OPENHOOK;
83 cif.openhook.base.next = &tap_log_attr;
84 cif.openhook.fn = clear_if_first;
85 tdb = tdb_open(name, TDB_DEFAULT, O_RDWR, 0, &cif);
86 if (!tdb) {
87 if (!locking_would_block)
88 diag("Opening tdb gave %s", strerror(errno));
89 forget_locking();
90 ret = OTHER_FAILURE;
91 } else
92 ret = SUCCESS;
93 break;
94 case FETCH:
95 ecode = tdb_fetch(tdb, k, &data);
96 if (ecode == TDB_ERR_NOEXIST) {
97 ret = FAILED;
98 } else if (ecode < 0) {
99 ret = OTHER_FAILURE;
100 } else if (!tdb_deq(data, k)) {
101 ret = OTHER_FAILURE;
102 free(data.dptr);
103 } else {
104 ret = SUCCESS;
105 free(data.dptr);
107 break;
108 case STORE:
109 ret = tdb_store(tdb, k, k, 0) == 0 ? SUCCESS : OTHER_FAILURE;
110 break;
111 case TRANSACTION_START:
112 ret = tdb_transaction_start(tdb) == 0 ? SUCCESS : OTHER_FAILURE;
113 break;
114 case TRANSACTION_COMMIT:
115 ret = tdb_transaction_commit(tdb)==0 ? SUCCESS : OTHER_FAILURE;
116 break;
117 case NEEDS_RECOVERY:
118 ret = tdb_needs_recovery(tdb) ? SUCCESS : FAILED;
119 break;
120 case CHECK:
121 ret = tdb_check(tdb, NULL, NULL) == 0 ? SUCCESS : OTHER_FAILURE;
122 break;
123 case CLOSE:
124 ret = tdb_close(tdb) == 0 ? SUCCESS : OTHER_FAILURE;
125 tdb = NULL;
126 break;
127 case SEND_SIGNAL:
128 /* We do this async */
129 ret = SUCCESS;
130 break;
131 default:
132 ret = OTHER_FAILURE;
135 if (locking_would_block)
136 ret = WOULD_HAVE_BLOCKED;
138 return ret;
141 struct agent {
142 int cmdfd, responsefd;
145 /* Do this before doing any tdb stuff. Return handle, or NULL. */
146 struct agent *prepare_external_agent(void)
148 int pid, ret;
149 int command[2], response[2];
150 char name[1+PATH_MAX];
152 if (pipe(command) != 0 || pipe(response) != 0)
153 return NULL;
155 pid = fork();
156 if (pid < 0)
157 return NULL;
159 if (pid != 0) {
160 struct agent *agent = malloc(sizeof(*agent));
162 close(command[0]);
163 close(response[1]);
164 agent->cmdfd = command[1];
165 agent->responsefd = response[0];
166 return agent;
169 close(command[1]);
170 close(response[0]);
172 /* We want to fail, not block. */
173 nonblocking_locks = true;
174 log_prefix = "external: ";
175 while ((ret = read(command[0], name, sizeof(name))) > 0) {
176 enum agent_return result;
178 result = do_operation(name[0], name+1);
179 if (write(response[1], &result, sizeof(result))
180 != sizeof(result))
181 err(1, "Writing response");
182 if (name[0] == SEND_SIGNAL) {
183 struct timeval ten_ms;
184 ten_ms.tv_sec = 0;
185 ten_ms.tv_usec = 10000;
186 select(0, NULL, NULL, NULL, &ten_ms);
187 kill(getppid(), SIGUSR1);
190 exit(0);
193 /* Ask the external agent to try to do an operation. */
194 enum agent_return external_agent_operation(struct agent *agent,
195 enum operation op,
196 const char *name)
198 enum agent_return res;
199 unsigned int len;
200 char *string;
202 if (!name)
203 name = "";
204 len = 1 + strlen(name) + 1;
205 string = malloc(len);
207 string[0] = op;
208 strcpy(string+1, name);
210 if (write(agent->cmdfd, string, len) != len
211 || read(agent->responsefd, &res, sizeof(res)) != sizeof(res))
212 res = AGENT_DIED;
214 free(string);
215 return res;
218 const char *agent_return_name(enum agent_return ret)
220 return ret == SUCCESS ? "SUCCESS"
221 : ret == WOULD_HAVE_BLOCKED ? "WOULD_HAVE_BLOCKED"
222 : ret == AGENT_DIED ? "AGENT_DIED"
223 : ret == FAILED ? "FAILED"
224 : ret == OTHER_FAILURE ? "OTHER_FAILURE"
225 : "**INVALID**";
228 const char *operation_name(enum operation op)
230 switch (op) {
231 case OPEN: return "OPEN";
232 case OPEN_WITH_HOOK: return "OPEN_WITH_HOOK";
233 case FETCH: return "FETCH";
234 case STORE: return "STORE";
235 case CHECK: return "CHECK";
236 case TRANSACTION_START: return "TRANSACTION_START";
237 case TRANSACTION_COMMIT: return "TRANSACTION_COMMIT";
238 case NEEDS_RECOVERY: return "NEEDS_RECOVERY";
239 case SEND_SIGNAL: return "SEND_SIGNAL";
240 case CLOSE: return "CLOSE";
242 return "**INVALID**";
245 void free_external_agent(struct agent *agent)
247 close(agent->cmdfd);
248 close(agent->responsefd);
249 free(agent);