ctdb/server/ctdb_logging.c

   1 /*
   2    ctdb logging code
   3
   4    Copyright (C) Andrew Tridgell  2008
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "replace.h"
  21 #include "system/filesys.h"
  22 #include "system/network.h"
  23 #include "system/time.h"
  24
  25 #include <talloc.h>
  26 #include <tevent.h>
  27
  28 #include "lib/util/dlinklist.h"
  29 #include "lib/util/debug.h"
  30 #include "lib/util/blocking.h"
  31 #include "lib/util/sys_rw.h"
  32 #include "lib/util/time.h"
  33
  34 #include "ctdb_private.h"
  35 #include "ctdb_client.h"
  36
  37 #include "common/common.h"
  38 #include "common/logging.h"
  39
  40 struct ctdb_log_state {
  41         const char *prefix;
  42         int fd, pfd;
  43         char buf[1024];
  44         uint16_t buf_used;
  45         void (*logfn)(const char *, uint16_t, void *);
  46         void *logfn_private;
  47 };
  48
  49 /* Used by ctdb_set_child_logging() */
  50 static struct ctdb_log_state *log_state;
  51
  52 /* Initialise logging */
  53 bool ctdb_logging_init(TALLOC_CTX *mem_ctx, const char *logging,
  54                        const char *debug_level)
  55 {
  56         int ret;
  57
  58         log_state = talloc_zero(mem_ctx, struct ctdb_log_state);
  59         if (log_state == NULL) {
  60                 return false;
  61         }
  62
  63         ret = logging_init(mem_ctx, logging, debug_level, "ctdbd");
  64         if (ret != 0) {
  65                 return false;
  66         }
  67
  68         return true;
  69 }
  70
  71 /* Note that do_debug always uses the global log state. */
  72 static void write_to_log(struct ctdb_log_state *log,
  73                          const char *buf, unsigned int len)
  74 {
  75         if (script_log_level <= DEBUGLEVEL) {
  76                 if (log != NULL && log->prefix != NULL) {
  77                         dbgtext("%s: %*.*s\n", log->prefix, len, len, buf);
  78                 } else {
  79                         dbgtext("%*.*s\n", len, len, buf);
  80                 }
  81                 /* log it in the eventsystem as well */
  82                 if (log && log->logfn) {
  83                         log->logfn(log->buf, len, log->logfn_private);
  84                 }
  85         }
  86 }
  87
  88 /*
  89   called when log data comes in from a child process
  90  */
  91 static void ctdb_child_log_handler(struct tevent_context *ev,
  92                                    struct tevent_fd *fde,
  93                                    uint16_t flags, void *private)
  94 {
  95         struct ctdb_log_state *log = talloc_get_type(private, struct ctdb_log_state);
  96         char *p;
  97         int n;
  98
  99         if (!(flags & TEVENT_FD_READ)) {
 100                 return;
 101         }
 102
 103         n = sys_read(log->pfd, &log->buf[log->buf_used],
 104                  sizeof(log->buf) - log->buf_used);
 105         if (n > 0) {
 106                 log->buf_used += n;
 107         } else if (n == 0) {
 108                 if (log != log_state) {
 109                         talloc_free(log);
 110                 }
 111                 return;
 112         }
 113
 114         while (log->buf_used > 0 &&
 115                (p = memchr(log->buf, '\n', log->buf_used)) != NULL) {
 116                 int n1 = (p - log->buf)+1;
 117                 int n2 = n1 - 1;
 118                 /* swallow \r from child processes */
 119                 if (n2 > 0 && log->buf[n2-1] == '\r') {
 120                         n2--;
 121                 }
 122                 write_to_log(log, log->buf, n2);
 123                 memmove(log->buf, p+1, sizeof(log->buf) - n1);
 124                 log->buf_used -= n1;
 125         }
 126
 127         /* the buffer could have completely filled - unfortunately we have
 128            no choice but to dump it out straight away */
 129         if (log->buf_used == sizeof(log->buf)) {
 130                 write_to_log(log, log->buf, log->buf_used);
 131                 log->buf_used = 0;
 132         }
 133 }
 134
 135 /*
 136   setup for logging of child process stdout
 137 */
 138 int ctdb_set_child_logging(struct ctdb_context *ctdb)
 139 {
 140         int p[2];
 141         int old_stdout, old_stderr;
 142         struct tevent_fd *fde;
 143
 144         /* setup a pipe to catch IO from subprocesses */
 145         if (pipe(p) != 0) {
 146                 DEBUG(DEBUG_ERR,(__location__ " Failed to setup for child logging pipe\n"));
 147                 return -1;
 148         }
 149
 150         /* We'll fail if stderr/stdout not already open; it's simpler. */
 151         old_stdout = dup(STDOUT_FILENO);
 152         if (old_stdout < 0) {
 153                 DEBUG(DEBUG_ERR, ("Failed to dup stdout for child logging\n"));
 154                 return -1;
 155         }
 156         old_stderr = dup(STDERR_FILENO);
 157         if (old_stderr < 0) {
 158                 DEBUG(DEBUG_ERR, ("Failed to dup stderr for child logging\n"));
 159                 close(old_stdout);
 160                 return -1;
 161         }
 162         if (dup2(p[1], STDOUT_FILENO) < 0 || dup2(p[1], STDERR_FILENO) < 0) {
 163                 int saved_errno = errno;
 164                 dup2(old_stdout, STDOUT_FILENO);
 165                 dup2(old_stderr, STDERR_FILENO);
 166                 close(old_stdout);
 167                 close(old_stderr);
 168                 close(p[0]);
 169                 close(p[1]);
 170                 errno = saved_errno;
 171
 172                 printf(__location__ " dup2 failed: %s\n",
 173                         strerror(errno));
 174                 return -1;
 175         }
 176         close(p[1]);
 177         close(old_stdout);
 178         close(old_stderr);
 179
 180         fde = tevent_add_fd(ctdb->ev, log_state, p[0], TEVENT_FD_READ,
 181                             ctdb_child_log_handler, log_state);
 182         tevent_fd_set_auto_close(fde);
 183
 184         log_state->pfd = p[0];
 185
 186         DEBUG(DEBUG_DEBUG, (__location__ " Created PIPE FD:%d for logging\n", p[0]));
 187
 188         return 0;
 189 }