src/audit/audit-sysvmq.c

   1 /*
   2  * Copyright 2009, Sine Nomine Associates and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afsconfig.h>
  11 #include <afs/param.h>
  12
  13 #include <roken.h>
  14
  15 /* only build on platforms that have SysV IPC support; i.e., when we
  16  * have sys/ipc.h */
  17 #ifdef HAVE_SYS_IPC_H
  18
  19 #include <sys/ipc.h>
  20 #include <sys/msg.h>
  21
  22 #include "audit-api.h"
  23
  24 /* solaris default is 2048 */
  25 #define MAXMSG 2048
  26
  27 /* message queue size will be increased to this value
  28    if not already bigger */
  29 #define MSGMNB (2*1024*1024)
  30
  31 static struct my_msgbuf {
  32     long mtype;
  33     char mtext[MAXMSG];
  34 } msgbuffer;
  35
  36 static int mqid;
  37
  38 static struct mqaudit_stats {
  39     long all;
  40     long truncated;
  41     long lost;
  42 } myauditstats;
  43
  44 static int truncated;
  45
  46 static void
  47 send_msg(void)
  48 {
  49     /* +1 to send the trailing '\0' in the message too so the
  50        receiver doesn't need to bother with it */
  51     if (msgsnd(mqid, &msgbuffer, strlen(msgbuffer.mtext)+1, IPC_NOWAIT) == -1) {
  52         myauditstats.lost++;
  53     } else if (truncated) {
  54         myauditstats.truncated++;
  55     }
  56     myauditstats.all++;
  57     msgbuffer.mtext[0] = 0;
  58     truncated = 0;
  59 }
  60
  61 static void
  62 append_msg(const char *format, ...)
  63 {
  64     va_list vaList;
  65     int size, printed;
  66
  67     size = MAXMSG - strlen(msgbuffer.mtext);
  68
  69     va_start(vaList, format);
  70     printed = vsnprintf(&msgbuffer.mtext[strlen(msgbuffer.mtext)], size, format, vaList);
  71     va_end(vaList);
  72
  73     /* A return value of size or more means that the output was truncated.
  74        If an output error is encountered, a negative value is returned. */
  75     if (size <= printed || printed == -1) {
  76         truncated = 1;
  77     }
  78 }
  79
  80 static int
  81 open_file(const char *fileName)
  82 {
  83     int tempfd;
  84     struct msqid_ds msqdesc;
  85
  86     msgbuffer.mtext[0] = 0;
  87     msgbuffer.mtype = 1;
  88
  89     truncated = 0;
  90     myauditstats.all = 0;
  91     myauditstats.lost = 0;
  92     myauditstats.truncated = 0;
  93
  94     /* try to create file for ftok if it doesn't already exist */
  95     tempfd = open(fileName, O_WRONLY | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
  96     if(tempfd != -1)
  97         close(tempfd);
  98
  99     mqid = msgget(ftok(fileName, 1), S_IRUSR | S_IWUSR | IPC_CREAT);
 100     if (mqid == -1) {
 101         printf("Warning: auditlog message queue %s cannot be opened.\n", fileName);
 102         return 1;
 103     }
 104
 105     /* increase message queue size */
 106     msgctl(mqid, IPC_STAT, &msqdesc);
 107     if (msqdesc.msg_qbytes < MSGMNB) {
 108         msqdesc.msg_qbytes = MSGMNB;
 109         msgctl(mqid, IPC_SET, &msqdesc);
 110     }
 111
 112     return 0;
 113 }
 114
 115 static void
 116 print_interface_stats(FILE *out)
 117 {
 118     fprintf(out, "audit statistics: %ld messages total, %ld truncated, %ld lost\n",
 119         myauditstats.all, myauditstats.truncated, myauditstats.lost);
 120 }
 121
 122 const struct osi_audit_ops audit_sysvmq_ops = {
 123     &send_msg,
 124     &append_msg,
 125     &open_file,
 126     &print_interface_stats,
 127 };
 128
 129 #endif /* HAVE_SYS_IPC_H */