procname.c

   1 /* $OpenBSD$ */
   2
   3 /*
   4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/param.h>
  20 #include <sys/sysctl.h>
  21 #include <sys/stat.h>
  22
  23 #include <errno.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27
  28 #ifndef nitems
  29 #define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
  30 #endif
  31
  32 #define is_runnable(p) \
  33         ((p)->p_stat == SRUN || (p)->p_stat == SIDL || (p)->p_stat == SONPROC)
  34 #define is_stopped(p) \
  35         ((p)->p_stat == SSTOP || (p)->p_stat == SZOMB || (p)->p_stat == SDEAD)
  36
  37 struct kinfo_proc       *cmp_procs(struct kinfo_proc *, struct kinfo_proc *);
  38 char            *get_proc_name(int, char *);
  39
  40 struct kinfo_proc *
  41 cmp_procs(struct kinfo_proc *p1, struct kinfo_proc *p2)
  42 {
  43         if (is_runnable(p1) && !is_runnable(p2))
  44                 return (p1);
  45         if (!is_runnable(p1) && is_runnable(p2))
  46                 return (p2);
  47
  48         if (is_stopped(p1) && !is_stopped(p2))
  49                 return (p1);
  50         if (!is_stopped(p1) && is_stopped(p2))
  51                 return (p2);
  52
  53         if (p1->p_estcpu > p2->p_estcpu)
  54                 return (p1);
  55         if (p1->p_estcpu < p2->p_estcpu)
  56                 return (p2);
  57
  58         if (p1->p_slptime < p2->p_slptime)
  59                 return (p1);
  60         if (p1->p_slptime > p2->p_slptime)
  61                 return (p2);
  62
  63         if ((p1->p_flag & P_SINTR) && !(p2->p_flag & P_SINTR))
  64                 return (p1);
  65         if (!(p1->p_flag & P_SINTR) && (p2->p_flag & P_SINTR))
  66                 return (p2);
  67
  68         if (strcmp(p1->p_comm, p2->p_comm) < 0)
  69                 return (p1);
  70         if (strcmp(p1->p_comm, p2->p_comm) > 0)
  71                 return (p2);
  72
  73         if (p1->p_pid > p2->p_pid)
  74                 return (p1);
  75         return (p2);
  76 }
  77
  78 char *
  79 get_proc_name(int fd, char *tty)
  80 {
  81         int              mib[6] = { CTL_KERN, KERN_PROC, KERN_PROC_PGRP, 0,
  82                                     sizeof(struct kinfo_proc), 0 };
  83         struct stat      sb;
  84         size_t           len;
  85         struct kinfo_proc *buf, *newbuf, *bestp;
  86         u_int            i;
  87         char            *name;
  88
  89         buf = NULL;
  90
  91         if (stat(tty, &sb) == -1)
  92                 return (NULL);
  93         if ((mib[3] = tcgetpgrp(fd)) == -1)
  94                 return (NULL);
  95
  96 retry:
  97         if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) == -1)
  98                 return (NULL);
  99         len = (len * 5) / 4;
 100
 101         if ((newbuf = realloc(buf, len)) == NULL)
 102                 goto error;
 103         buf = newbuf;
 104
 105         mib[5] = (int)(len / sizeof(struct kinfo_proc));
 106         if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) == -1) {
 107                 if (errno == ENOMEM)
 108                         goto retry;
 109                 goto error;
 110         }
 111
 112         bestp = NULL;
 113         for (i = 0; i < len / sizeof (struct kinfo_proc); i++) {
 114                 if ((dev_t)buf[i].p_tdev != sb.st_rdev)
 115                         continue;
 116                 if (bestp == NULL)
 117                         bestp = &buf[i];
 118                 else
 119                         bestp = cmp_procs(&buf[i], bestp);
 120         }
 121
 122         name = NULL;
 123         if (bestp != NULL)
 124                 name = strdup(bestp->p_comm);
 125
 126         free(buf);
 127         return (name);
 128
 129 error:
 130         free(buf);
 131         return (NULL);
 132 }