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-rw-r--r--libblkid/lib/procutils.c264
1 files changed, 264 insertions, 0 deletions
diff --git a/libblkid/lib/procutils.c b/libblkid/lib/procutils.c
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index 000000000..ef969417d
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+++ b/libblkid/lib/procutils.c
@@ -0,0 +1,264 @@
+/*
+ * Copyright (C) 2011 Davidlohr Bueso <dave@gnu.org>
+ *
+ * procutils.c: General purpose procfs parsing utilities
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Library Public License for more details.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <ctype.h>
+
+#include "procutils.h"
+#include "at.h"
+#include "c.h"
+
+/*
+ * @pid: process ID for which we want to obtain the threads group
+ *
+ * Returns: newly allocated tasks structure
+ */
+struct proc_tasks *proc_open_tasks(pid_t pid)
+{
+ struct proc_tasks *tasks;
+ char path[PATH_MAX];
+
+ sprintf(path, "/proc/%d/task/", pid);
+
+ tasks = malloc(sizeof(struct proc_tasks));
+ if (tasks) {
+ tasks->dir = opendir(path);
+ if (tasks->dir)
+ return tasks;
+ }
+
+ free(tasks);
+ return NULL;
+}
+
+/*
+ * @tasks: allocated tasks structure
+ *
+ * Returns: nothing
+ */
+void proc_close_tasks(struct proc_tasks *tasks)
+{
+ if (tasks && tasks->dir)
+ closedir(tasks->dir);
+ free(tasks);
+}
+
+/*
+ * @tasks: allocated task structure
+ * @tid: [output] one of the thread IDs belonging to the thread group
+ * If when an error occurs, it is set to 0.
+ *
+ * Returns: 0 on success, 1 on end, -1 on failure or no more threads
+ */
+int proc_next_tid(struct proc_tasks *tasks, pid_t *tid)
+{
+ struct dirent *d;
+ char *end;
+
+ if (!tasks || !tid)
+ return -EINVAL;
+
+ *tid = 0;
+ errno = 0;
+
+ do {
+ d = readdir(tasks->dir);
+ if (!d)
+ return errno ? -1 : 1; /* error or end-of-dir */
+
+ if (!isdigit((unsigned char) *d->d_name))
+ continue;
+ errno = 0;
+ *tid = (pid_t) strtol(d->d_name, &end, 10);
+ if (errno || d->d_name == end || (end && *end))
+ return -1;
+
+ } while (!*tid);
+
+ return 0;
+}
+
+struct proc_processes *proc_open_processes(void)
+{
+ struct proc_processes *ps;
+
+ ps = calloc(1, sizeof(struct proc_processes));
+ if (ps) {
+ ps->dir = opendir("/proc");
+ if (ps->dir)
+ return ps;
+ }
+
+ free(ps);
+ return NULL;
+}
+
+void proc_close_processes(struct proc_processes *ps)
+{
+ if (ps && ps->dir)
+ closedir(ps->dir);
+ free(ps);
+}
+
+void proc_processes_filter_by_name(struct proc_processes *ps, const char *name)
+{
+ ps->fltr_name = name;
+ ps->has_fltr_name = name ? 1 : 0;
+}
+
+void proc_processes_filter_by_uid(struct proc_processes *ps, uid_t uid)
+{
+ ps->fltr_uid = uid;
+ ps->has_fltr_uid = 1;
+}
+
+int proc_next_pid(struct proc_processes *ps, pid_t *pid)
+{
+ struct dirent *d;
+
+ if (!ps || !pid)
+ return -EINVAL;
+
+ *pid = 0;
+ errno = 0;
+
+ do {
+ char buf[BUFSIZ], *p;
+
+ d = readdir(ps->dir);
+ if (!d)
+ return errno ? -1 : 1; /* error or end-of-dir */
+
+
+ if (!isdigit((unsigned char) *d->d_name))
+ continue;
+
+ /* filter out by UID */
+ if (ps->has_fltr_uid) {
+ struct stat st;
+
+ if (fstat_at(dirfd(ps->dir), "/proc", d->d_name, &st, 0))
+ continue;
+ if (ps->fltr_uid != st.st_uid)
+ continue;
+ }
+
+ /* filter out by NAME */
+ if (ps->has_fltr_name) {
+ char procname[256];
+ FILE *f;
+
+ snprintf(buf, sizeof(buf), "%s/stat", d->d_name);
+ f = fopen_at(dirfd(ps->dir), "/proc", buf,
+ O_CLOEXEC|O_RDONLY, "r");
+ if (!f)
+ continue;
+
+ p = fgets(buf, sizeof(buf), f);
+ fclose(f);
+ if (!p)
+ continue;
+
+ if (sscanf(buf, "%*d (%255[^)])", procname) != 1)
+ continue;
+
+ /* ok, we got the process name. */
+ if (strcmp(procname, ps->fltr_name) != 0)
+ continue;
+ }
+
+ p = NULL;
+ errno = 0;
+ *pid = (pid_t) strtol(d->d_name, &p, 10);
+ if (errno || d->d_name == p || (p && *p))
+ return errno ? -errno : -1;
+
+ return 0;
+ } while (1);
+
+ return 0;
+}
+
+#ifdef TEST_PROGRAM
+
+static int test_tasks(int argc, char *argv[])
+{
+ pid_t tid, pid;
+ struct proc_tasks *ts;
+
+ if (argc != 2)
+ return EXIT_FAILURE;
+
+ pid = strtol(argv[1], (char **) NULL, 10);
+ printf("PID=%d, TIDs:", pid);
+
+ ts = proc_open_tasks(pid);
+ if (!ts)
+ err(EXIT_FAILURE, "open list of tasks failed");
+
+ while (proc_next_tid(ts, &tid) == 0)
+ printf(" %d", tid);
+
+ printf("\n");
+ proc_close_tasks(ts);
+ return EXIT_SUCCESS;
+}
+
+static int test_processes(int argc, char *argv[])
+{
+ pid_t pid;
+ struct proc_processes *ps;
+
+ ps = proc_open_processes();
+ if (!ps)
+ err(EXIT_FAILURE, "open list of processes failed");
+
+ if (argc >= 3 && strcmp(argv[1], "--name") == 0)
+ proc_processes_filter_by_name(ps, argv[2]);
+
+ if (argc >= 3 && strcmp(argv[1], "--uid") == 0)
+ proc_processes_filter_by_uid(ps, (uid_t) atol(argv[2]));
+
+ while (proc_next_pid(ps, &pid) == 0)
+ printf(" %d", pid);
+
+ printf("\n");
+ proc_close_processes(ps);
+ return EXIT_SUCCESS;
+}
+
+int main(int argc, char *argv[])
+{
+ if (argc < 2) {
+ fprintf(stderr, "usage: %1$s --tasks <pid>\n"
+ " %1$s --processes [---name <name>] [--uid <uid>]\n",
+ program_invocation_short_name);
+ return EXIT_FAILURE;
+ }
+
+ if (strcmp(argv[1], "--tasks") == 0)
+ return test_tasks(argc - 1, argv + 1);
+ if (strcmp(argv[1], "--processes") == 0)
+ return test_processes(argc - 1, argv + 1);
+
+ return EXIT_FAILURE;
+}
+#endif /* TEST_PROGRAM */