1 /*
2 Copyright 2021 Northern.tech AS
3
4 This file is part of CFEngine 3 - written and maintained by Northern.tech AS.
5
6 This program is free software; you can redistribute it and/or modify it
7 under the terms of the GNU General Public License as published by the
8 Free Software Foundation; version 3.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software
17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
18
19 To the extent this program is licensed as part of the Enterprise
20 versions of CFEngine, the applicable Commercial Open Source License
21 (COSL) may apply to this file if you as a licensee so wish it. See
22 included file COSL.txt.
23 */
24
25 #include <cf3.defs.h>
26
27 #include <process_lib.h>
28 #include <process_unix_priv.h>
29 #include <files_lib.h>
30
31
32 typedef struct
33 {
34 time_t starttime;
35 char state;
36 } ProcessStat;
37
GetProcessStat(pid_t pid,ProcessStat * state)38 static bool GetProcessStat(pid_t pid, ProcessStat *state)
39 {
40 char filename[64];
41 xsnprintf(filename, sizeof(filename), "/proc/%jd/stat", (intmax_t) pid);
42
43 int fd;
44 for (;;)
45 {
46 if ((fd = open(filename, O_RDONLY)) != -1)
47 {
48 break;
49 }
50
51 if (errno == EINTR)
52 {
53 continue;
54 }
55
56 if (errno == ENOENT || errno == ENOTDIR)
57 {
58 return false;
59 }
60
61 if (errno == EACCES)
62 {
63 return false;
64 }
65
66 assert (fd != -1 && "Unable to open /proc/<pid>/stat");
67 }
68
69 char stat[CF_BUFSIZE];
70 int res = FullRead(fd, stat, sizeof(stat) - 1); /* -1 for the '\0', below */
71 close(fd);
72
73 if (res < 0)
74 {
75 return false;
76 }
77 assert(res < CF_BUFSIZE);
78 stat[res] = '\0'; /* read() doesn't '\0'-terminate */
79
80 /* stat entry is of form: <pid> (<task name>) <various info...>
81 * To avoid choking on weird task names, we search for the closing
82 * parenthesis first: */
83 char *p = memrchr(stat, ')', res);
84 if (p == NULL)
85 {
86 /* Wrong field format! */
87 return false;
88 }
89
90 p++; // Skip the parenthesis
91
92 char proc_state[2];
93 unsigned long long starttime;
94
95 if (sscanf(p,
96 "%1s" /* state */
97 "%*s" /* ppid */
98 "%*s" /* pgrp */
99 "%*s" /* session */
100 "%*s" /* tty_nr */
101 "%*s" /* tpgid */
102 "%*s" /* flags */
103 "%*s" /* minflt */
104 "%*s" /* cminflt */
105 "%*s" /* majflt */
106 "%*s" /* cmajflt */
107 "%*s" /* utime */
108 "%*s" /* stime */
109 "%*s" /* cutime */
110 "%*s" /* cstime */
111 "%*s" /* priority */
112 "%*s" /* nice */
113 "%*s" /* num_threads */
114 "%*s" /* itrealvalue */
115 "%llu" /* starttime */,
116 proc_state,
117 &starttime) != 2)
118 {
119 return false;
120 }
121
122 state->state = proc_state[0];
123 state->starttime = (time_t)(starttime / sysconf(_SC_CLK_TCK));
124
125 return true;
126 }
127
GetProcessStartTime(pid_t pid)128 time_t GetProcessStartTime(pid_t pid)
129 {
130 ProcessStat st;
131 if (GetProcessStat(pid, &st))
132 {
133 return st.starttime;
134 }
135 else
136 {
137 return PROCESS_START_TIME_UNKNOWN;
138 }
139 }
140
GetProcessState(pid_t pid)141 ProcessState GetProcessState(pid_t pid)
142 {
143 ProcessStat st;
144 if (GetProcessStat(pid, &st))
145 {
146 switch (st.state)
147 {
148 case 'T':
149 return PROCESS_STATE_STOPPED;
150 case 'Z':
151 return PROCESS_STATE_ZOMBIE;
152 default:
153 return PROCESS_STATE_RUNNING;
154 }
155 }
156 else
157 {
158 return PROCESS_STATE_DOES_NOT_EXIST;
159 }
160 }
161