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Diffstat (limited to 'libblkid/lib/procutils.c')
| -rw-r--r-- | libblkid/lib/procutils.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/libblkid/lib/procutils.c b/libblkid/lib/procutils.c new file mode 100644 index 000000000..ef969417d --- /dev/null +++ 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 */ |