--- /dev/null
+#define _GNU_SOURCE /* See feature_test_macros(7) */
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <inttypes.h>
+
+#define event_list "lttng_statedump_start,lttng_statedump_end," \
+ "lttng_statedump_process_state,lttng_statedump_file_descriptor," \
+ "lttng_statedump_vm_map,lttng_statedump_network_interface," \
+ "lttng_statedump_interrupt,sched_process_free," \
+ "sched_switch,sched_process_fork"
+#define context_list "-t pid -t procname -t tid -t ppid "
+
+static
+int check_or_start_sessiond()
+{
+ int ret;
+ int sudo = 0;
+
+ ret = system("pgrep -u root lttng-sessiond >/dev/null");
+ if (ret == 0)
+ goto end;
+
+ if (getuid() != 0) {
+ fprintf(stderr, "Trying to start lttng-sessiond with sudo\n");
+ ret = system("sudo -l lttng-sessiond >/dev/null");
+ if (ret < 0) {
+ fprintf(stderr, "[error] You are not root and not "
+ "allowed by sudo to start lttng-sessiond\n");
+ ret = -1;
+ goto end;
+ }
+ sudo = 1;
+ }
+
+ if (sudo)
+ ret = system("sudo lttng-sessiond -d");
+ else
+ ret = system("lttng-sessiond -d");
+
+ if (ret != 0) {
+ fprintf(stderr, "Error starting lttng-sessiond as root\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int check_or_start_relayd()
+{
+ int ret;
+
+ ret = system("pgrep lttng-relayd >/dev/null");
+ if (ret == 0)
+ goto end;
+
+ ret = system("lttng-relayd -d");
+ if (ret != 0) {
+ fprintf(stderr, "Error starting lttng-relayd\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+/*
+ * Return 0 if in tracing group or root, 1 if sudo is needed (and working),
+ * a negative value on error.
+ */
+static
+int check_tracing_group()
+{
+ int ret;
+
+ ret = getuid();
+ if (ret == 0)
+ goto end;
+
+ ret = system("groups|grep tracing >/dev/null");
+ if (ret == 0) {
+ goto end;
+ }
+
+ ret = system("sudo lttng --version >/dev/null");
+ if (ret != 0) {
+ fprintf(stderr, "Error executing lttng with sudo, you need to "
+ "be root or in the \"tracing\" group to start "
+ "kernel tracing\n");
+ ret = -1;
+ goto end;
+ } else {
+ ret = 1;
+ }
+
+end:
+ return ret;
+}
+
+static
+int check_lttng_modules(int sudo)
+{
+ int ret;
+
+ if (sudo) {
+ ret = system("sudo lttng list -k | grep sched_switch >/dev/null");
+ } else {
+ ret = system("lttng list -k | grep sched_switch >/dev/null");
+ }
+ if (ret != 0) {
+ fprintf(stderr, "Error listing kernel events, "
+ "lttng-modules might not be installed\n");
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int check_requirements(int *sudo)
+{
+ int ret;
+
+ ret = check_or_start_sessiond();
+ if (ret < 0)
+ goto end;
+ ret = check_or_start_relayd();
+ if (ret < 0)
+ goto end;
+ ret = check_tracing_group();
+ if (ret < 0)
+ goto end;
+ else if (ret == 1)
+ *sudo = 1;
+
+ ret = check_lttng_modules(*sudo);
+ if (ret < 0)
+ goto end;
+end:
+ return ret;
+}
+
+/*
+ * Allocate a random string, must be freed by the caller.
+ */
+static
+char *random_session_name()
+{
+ uint64_t id;
+ char *str = NULL;
+ int ret;
+
+ FILE *f = fopen( "/dev/urandom", "r");
+ if (!f) {
+ perror("fopen");
+ goto end;
+ }
+
+ ret = fread(&id, 1, sizeof(uint64_t), f);
+ if (ret < sizeof(id)) {
+ perror("fread");
+ goto end;
+ }
+
+ ret = asprintf(&str, "lttngtop-%" PRIu64, id);
+ if (ret < 0) {
+ fprintf(stderr, "Error allocating session name");
+ str = NULL;
+ goto end;
+ }
+
+ ret = fclose(f);
+ if (ret != 0) {
+ perror("fclose");
+ goto end;
+ }
+
+end:
+ return str;
+}
+
+static
+int check_session_name(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng list | grep %s >/dev/null",
+ (sudo) ? "sudo" : " ", name);
+ if (ret < 0) {
+ fprintf(stderr, "Allocating cmd\n");
+ goto end;
+ }
+
+ ret = (system(cmd));
+ if (ret == 0) {
+ fprintf(stderr, "Error: session %s already exist, either we "
+ "are not random enough or something is "
+ "really wrong\n", name);
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int local_session(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng create %s >/dev/null",
+ (sudo) ? "sudo" : " ", name);
+ if (ret < 0) {
+ fprintf(stderr, "Allocating cmd\n");
+ goto end;
+ }
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "Error: creating the session\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int enable_event(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng enable-event -s %s -k %s >/dev/null",
+ (sudo) ? "sudo" : " ", name, event_list);
+ if (ret < 0) {
+ fprintf(stderr, "Allocating cmd\n");
+ goto end;
+ }
+
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "Error: enabling events\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int add_contexts(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng add-context -s %s -k %s >/dev/null",
+ (sudo) ? "sudo" : " ", name, context_list);
+ if (ret < 0) {
+ fprintf(stderr, "allocating cmd\n");
+ goto end;
+ }
+
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "error: adding contexts\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int start(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng start %s >/dev/null",
+ (sudo) ? "sudo" : " ", name);
+ if (ret < 0) {
+ fprintf(stderr, "allocating cmd\n");
+ goto end;
+ }
+
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "error: starting the session %s\n", name);
+ ret = -1;
+ goto end;
+ }
+
+ ret = sprintf(cmd, "%s lttng list|grep %s|cut -d'(' -f2|cut -d ')' -f1",
+ (sudo) ? "sudo" : " ", name);
+ if (ret < 0) {
+ fprintf(stderr, "allocating cmd\n");
+ goto end;
+ }
+ fprintf(stderr, "Local session started in ");
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "error: listing the sessions\n");
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+static
+int destroy(char *name, int sudo)
+{
+ int ret;
+ char cmd[1024];
+
+ ret = sprintf(cmd, "%s lttng destroy %s >/dev/null",
+ (sudo) ? "sudo" : " ", name);
+ if (ret < 0) {
+ fprintf(stderr, "allocating cmd\n");
+ goto end;
+ }
+
+ ret = (system(cmd));
+ if (ret != 0) {
+ fprintf(stderr, "error: destroying the session %s\n", name);
+ ret = -1;
+ goto end;
+ }
+
+end:
+ return ret;
+}
+
+int create_local_session()
+{
+ int ret;
+ char *name;
+ int sudo = 0;
+
+ ret = check_requirements(&sudo);
+
+ name = random_session_name();
+ if (!name) {
+ ret = -1;
+ goto end;
+ }
+
+ ret = check_session_name(name, sudo);
+ if (ret < 0) {
+ goto end_free;
+ }
+
+ ret = local_session(name, sudo);
+ if (ret < 0) {
+ goto end_free;
+ }
+
+ ret = enable_event(name, sudo);
+ if (ret < 0) {
+ goto end_free;
+ }
+
+ ret = add_contexts(name, sudo);
+ if (ret < 0) {
+ goto end_free;
+ }
+
+ ret = start(name, sudo);
+ if (ret < 0) {
+ goto end_free;
+ }
+
+end_free:
+ free(name);
+end:
+ return ret;
+}
+
+int destroy_local_session(char *name, int sudo)
+{
+ return destroy(name, sudo);
+}
+
+/*
+int create_live_local_session();
+int destroy_live_local_session();
+*/
projects / lttngtop.git / blobdiff