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         int fd, pfd;
  42         char buf[1024];
  43         uint16_t buf_used;
  44 };
  45
  46 /* Used by ctdb_set_child_logging() */
  47 static struct ctdb_log_state *log_state;
  48
  49 /* Initialise logging */
  50 bool ctdb_logging_init(TALLOC_CTX *mem_ctx, const char *logging,
  51                        const char *debug_level)
  52 {
  53         int ret;
  54
  55         log_state = talloc_zero(mem_ctx, struct ctdb_log_state);
  56         if (log_state == NULL) {
  57                 return false;
  58         }
  59
  60         ret = logging_init(mem_ctx, logging, debug_level, "ctdbd");
  61         if (ret != 0) {
  62                 return false;
  63         }
  64
  65         return true;
  66 }
  67
  68 static void write_to_log(const char *buf, unsigned int len)
  69 {
  70         DEBUG(script_log_level, ("%*.*s\n", len, len, buf));
  71 }
  72
  73 /*
  74   called when log data comes in from a child process
  75  */
  76 static void ctdb_child_log_handler(struct tevent_context *ev,
  77                                    struct tevent_fd *fde,
  78                                    uint16_t flags, void *private)
  79 {
  80         struct ctdb_log_state *log = talloc_get_type(private, struct ctdb_log_state);
  81         char *p;
  82         int n;
  83
  84         if (!(flags & TEVENT_FD_READ)) {
  85                 return;
  86         }
  87
  88         n = sys_read(log->pfd, &log->buf[log->buf_used],
  89                  sizeof(log->buf) - log->buf_used);
  90         if (n > 0) {
  91                 log->buf_used += n;
  92         } else if (n == 0) {
  93                 if (log != log_state) {
  94                         talloc_free(log);
  95                 }
  96                 return;
  97         }
  98
  99         while (log->buf_used > 0 &&
 100                (p = memchr(log->buf, '\n', log->buf_used)) != NULL) {
 101                 int n1 = (p - log->buf)+1;
 102                 int n2 = n1 - 1;
 103                 /* swallow \r from child processes */
 104                 if (n2 > 0 && log->buf[n2-1] == '\r') {
 105                         n2--;
 106                 }
 107                 write_to_log(log->buf, n2);
 108                 memmove(log->buf, p+1, sizeof(log->buf) - n1);
 109                 log->buf_used -= n1;
 110         }
 111
 112         /* the buffer could have completely filled - unfortunately we have
 113            no choice but to dump it out straight away */
 114         if (log->buf_used == sizeof(log->buf)) {
 115                 write_to_log(log->buf, log->buf_used);
 116                 log->buf_used = 0;
 117         }
 118 }
 119
 120 /*
 121   setup for logging of child process stdout
 122 */
 123 int ctdb_set_child_logging(struct ctdb_context *ctdb)
 124 {
 125         int p[2];
 126         int old_stdout, old_stderr;
 127         struct tevent_fd *fde;
 128
 129         /* setup a pipe to catch IO from subprocesses */
 130         if (pipe(p) != 0) {
 131                 DEBUG(DEBUG_ERR,(__location__ " Failed to setup for child logging pipe\n"));
 132                 return -1;
 133         }
 134
 135         /* We'll fail if stderr/stdout not already open; it's simpler. */
 136         old_stdout = dup(STDOUT_FILENO);
 137         if (old_stdout < 0) {
 138                 DEBUG(DEBUG_ERR, ("Failed to dup stdout for child logging\n"));
 139                 return -1;
 140         }
 141         old_stderr = dup(STDERR_FILENO);
 142         if (old_stderr < 0) {
 143                 DEBUG(DEBUG_ERR, ("Failed to dup stderr for child logging\n"));
 144                 close(old_stdout);
 145                 return -1;
 146         }
 147         if (dup2(p[1], STDOUT_FILENO) < 0 || dup2(p[1], STDERR_FILENO) < 0) {
 148                 int saved_errno = errno;
 149                 dup2(old_stdout, STDOUT_FILENO);
 150                 dup2(old_stderr, STDERR_FILENO);
 151                 close(old_stdout);
 152                 close(old_stderr);
 153                 close(p[0]);
 154                 close(p[1]);
 155                 errno = saved_errno;
 156
 157                 printf(__location__ " dup2 failed: %s\n",
 158                         strerror(errno));
 159                 return -1;
 160         }
 161         close(p[1]);
 162         close(old_stdout);
 163         close(old_stderr);
 164
 165         fde = tevent_add_fd(ctdb->ev, log_state, p[0], TEVENT_FD_READ,
 166                             ctdb_child_log_handler, log_state);
 167         tevent_fd_set_auto_close(fde);
 168
 169         log_state->pfd = p[0];
 170
 171         DEBUG(DEBUG_DEBUG, (__location__ " Created PIPE FD:%d for logging\n", p[0]));
 172
 173         return 0;
 174 }