Fix: Use unix socket peercred for pid, uid, gid credentials
[deliverable/lttng-ust.git] / liblttng-ust-ctl / ustctl.c
index 10fb9c4921f36ba4b4955fe90b892aeb9ce08e9b..048d0127ee459d786c14b8b350f0da3e79e3c570 100644 (file)
 
 #define _GNU_SOURCE
 #include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <lttng/ust-config.h>
 #include <lttng/ust-ctl.h>
 #include <lttng/ust-abi.h>
 #include <lttng/ust-events.h>
@@ -33,6 +37,7 @@
 #include "../liblttng-ust/wait.h"
 #include "../liblttng-ust/lttng-rb-clients.h"
 #include "../liblttng-ust/clock.h"
+#include "../liblttng-ust/getenv.h"
 
 /*
  * Number of milliseconds to retry before failing metadata writes on
@@ -75,8 +80,6 @@ extern void lttng_ring_buffer_client_discard_exit(void);
 extern void lttng_ring_buffer_client_discard_rt_exit(void);
 extern void lttng_ring_buffer_metadata_client_exit(void);
 
-volatile enum ust_loglevel ust_loglevel;
-
 int ustctl_release_handle(int sock, int handle)
 {
        struct ustcomm_ust_msg lum;
@@ -109,8 +112,10 @@ int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
                                ret = -errno;
                                return ret;
                        }
+                       data->u.channel.wakeup_fd = -1;
                }
                free(data->u.channel.data);
+               data->u.channel.data = NULL;
                break;
        case LTTNG_UST_OBJECT_TYPE_STREAM:
                if (data->u.stream.shm_fd >= 0) {
@@ -119,6 +124,7 @@ int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
                                ret = -errno;
                                return ret;
                        }
+                       data->u.stream.shm_fd = -1;
                }
                if (data->u.stream.wakeup_fd >= 0) {
                        ret = close(data->u.stream.wakeup_fd);
@@ -126,6 +132,7 @@ int ustctl_release_object(int sock, struct lttng_ust_object_data *data)
                                ret = -errno;
                                return ret;
                        }
+                       data->u.stream.wakeup_fd = -1;
                }
                break;
        case LTTNG_UST_OBJECT_TYPE_EVENT:
@@ -1055,7 +1062,8 @@ struct ustctl_consumer_channel *
                        attr->switch_timer_interval,
                        attr->read_timer_interval,
                        attr->uuid, attr->chan_id,
-                       stream_fds, nr_stream_fds);
+                       stream_fds, nr_stream_fds,
+                       attr->blocking_timeout);
        if (!chan->chan) {
                goto chan_error;
        }
@@ -1499,6 +1507,25 @@ int ustctl_snapshot(struct ustctl_consumer_stream *stream)
                        &buf->prod_snapshot, consumer_chan->chan->handle);
 }
 
+/*
+ * Get a snapshot of the current ring buffer producer and consumer positions
+ * even if the consumed and produced positions are contained within the same
+ * subbuffer.
+ */
+int ustctl_snapshot_sample_positions(struct ustctl_consumer_stream *stream)
+{
+       struct lttng_ust_lib_ring_buffer *buf;
+       struct ustctl_consumer_channel *consumer_chan;
+
+       if (!stream)
+               return -EINVAL;
+       buf = stream->buf;
+       consumer_chan = stream->chan;
+       return lib_ring_buffer_snapshot_sample_positions(buf,
+                       &buf->cons_snapshot, &buf->prod_snapshot,
+                       consumer_chan->chan->handle);
+}
+
 /* Get the consumer position (iteration start) */
 int ustctl_snapshot_get_consumed(struct ustctl_consumer_stream *stream,
                unsigned long *pos)
@@ -1568,6 +1595,19 @@ void ustctl_flush_buffer(struct ustctl_consumer_stream *stream,
                consumer_chan->chan->handle);
 }
 
+void ustctl_clear_buffer(struct ustctl_consumer_stream *stream)
+{
+       struct lttng_ust_lib_ring_buffer *buf;
+       struct ustctl_consumer_channel *consumer_chan;
+
+       assert(stream);
+       buf = stream->buf;
+       consumer_chan = stream->chan;
+       lib_ring_buffer_switch_slow(buf, SWITCH_ACTIVE,
+               consumer_chan->chan->handle);
+       lib_ring_buffer_clear_reader(buf, consumer_chan->chan->handle);
+}
+
 static
 struct lttng_ust_client_lib_ring_buffer_client_cb *get_client_cb(
                struct lttng_ust_lib_ring_buffer *buf,
@@ -1708,7 +1748,41 @@ int ustctl_get_current_timestamp(struct ustctl_consumer_stream *stream,
        return client_cb->current_timestamp(buf, handle, ts);
 }
 
-#if defined(__x86_64__) || defined(__i386__)
+int ustctl_get_sequence_number(struct ustctl_consumer_stream *stream,
+               uint64_t *seq)
+{
+       struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
+       struct lttng_ust_lib_ring_buffer *buf;
+       struct lttng_ust_shm_handle *handle;
+
+       if (!stream || !seq)
+               return -EINVAL;
+       buf = stream->buf;
+       handle = stream->chan->chan->handle;
+       client_cb = get_client_cb(buf, handle);
+       if (!client_cb || !client_cb->sequence_number)
+               return -ENOSYS;
+       return client_cb->sequence_number(buf, handle, seq);
+}
+
+int ustctl_get_instance_id(struct ustctl_consumer_stream *stream,
+               uint64_t *id)
+{
+       struct lttng_ust_client_lib_ring_buffer_client_cb *client_cb;
+       struct lttng_ust_lib_ring_buffer *buf;
+       struct lttng_ust_shm_handle *handle;
+
+       if (!stream || !id)
+               return -EINVAL;
+       buf = stream->buf;
+       handle = stream->chan->chan->handle;
+       client_cb = get_client_cb(buf, handle);
+       if (!client_cb)
+               return -ENOSYS;
+       return client_cb->instance_id(buf, handle, id);
+}
+
+#ifdef LTTNG_UST_HAVE_PERF_EVENT
 
 int ustctl_has_perf_counters(void)
 {
@@ -1724,6 +1798,104 @@ int ustctl_has_perf_counters(void)
 
 #endif
 
+#ifdef __linux__
+/*
+ * Override application pid/uid/gid with unix socket credentials. If
+ * the application announced a pid matching our view, it means it is
+ * within the same pid namespace, so expose the ppid provided by the
+ * application.
+ */
+static
+int get_cred(int sock,
+       const struct ustctl_reg_msg *reg_msg,
+       uint32_t *pid,
+       uint32_t *ppid,
+       uint32_t *uid,
+       uint32_t *gid)
+{
+       struct ucred ucred;
+       socklen_t ucred_len = sizeof(struct ucred);
+       int ret;
+
+       ret = getsockopt(sock, SOL_SOCKET, SO_PEERCRED, &ucred, &ucred_len);
+       if (ret) {
+               return -LTTNG_UST_ERR_PEERCRED;
+       }
+       DBG("Unix socket peercred [ pid: %u, uid: %u, gid: %u ], "
+               "application registered claiming [ pid: %u, ppid: %u, uid: %u, gid: %u ]",
+               ucred.pid, ucred.uid, ucred.gid,
+               reg_msg->pid, reg_msg->ppid, reg_msg->uid, reg_msg->gid);
+       if (!ucred.pid) {
+               ERR("Unix socket credential pid=0. Refusing application in distinct, non-nested pid namespace.");
+               return -LTTNG_UST_ERR_PEERCRED_PID;
+       }
+       *pid = ucred.pid;
+       *uid = ucred.uid;
+       *gid = ucred.gid;
+       if (ucred.pid == reg_msg->pid) {
+               *ppid = reg_msg->ppid;
+       } else {
+               *ppid = 0;
+       }
+       return 0;
+}
+#elif defined(__FreeBSD__)
+#include <sys/ucred.h>
+
+/*
+ * Override application uid/gid with unix socket credentials. Use the
+ * first group of the cr_groups.
+ * Use the pid and ppid provided by the application on registration.
+ */
+static
+int get_cred(int sock,
+       const struct ustctl_reg_msg *reg_msg,
+       uint32_t *pid,
+       uint32_t *ppid,
+       uint32_t *uid,
+       uint32_t *gid)
+{
+       struct xucred xucred;
+       socklen_t xucred_len = sizeof(struct xucred);
+       int ret;
+
+       ret = getsockopt(sock, SOL_SOCKET, LOCAL_PEERCRED, &xucred, &xucred_len);
+       if (ret) {
+               return -LTTNG_UST_ERR_PEERCRED;
+       }
+       if (xucred.cr_version != XUCRED_VERSION || xucred.cr_ngroups < 1) {
+               return -LTTNG_UST_ERR_PEERCRED;
+       }
+       DBG("Unix socket peercred [ uid: %u, gid: %u ], "
+               "application registered claiming [ pid: %d, ppid: %d, uid: %u, gid: %u ]",
+               xucred.uid, xucred.cr_groups[0],
+               reg_msg->pid, reg_msg->ppid, reg_msg->uid, reg_msg->gid);
+       *pid = reg_msg->pid;
+       *ppid = reg_msg->ppid;
+       *uid = xucred.uid;
+       *gid = xucred.cr_groups[0];
+       return 0;
+}
+#else
+#warning "Using insecure fallback: trusting user id provided by registered applications. Please consider implementing use of unix socket credentials on your platform."
+static
+int get_cred(int sock,
+       const struct ustctl_reg_msg *reg_msg,
+       uint32_t *pid,
+       uint32_t *ppid,
+       uint32_t *uid,
+       uint32_t *gid)
+{
+       DBG("Application registered claiming [ pid: %u, ppid: %d, uid: %u, gid: %u ]",
+               reg_msg->pid, reg_msg->ppid, reg_msg->uid, reg_msg->gid);
+       *pid = reg_msg->pid;
+       *ppid = reg_msg->ppid;
+       *uid = reg_msg->uid;
+       *gid = reg_msg->gid;
+       return 0;
+}
+#endif
+
 /*
  * Returns 0 on success, negative error value on error.
  */
@@ -1774,10 +1946,6 @@ int ustctl_recv_reg_msg(int sock,
        }
        *major = reg_msg.major;
        *minor = reg_msg.minor;
-       *pid = reg_msg.pid;
-       *ppid = reg_msg.ppid;
-       *uid = reg_msg.uid;
-       *gid = reg_msg.gid;
        *bits_per_long = reg_msg.bits_per_long;
        *uint8_t_alignment = reg_msg.uint8_t_alignment;
        *uint16_t_alignment = reg_msg.uint16_t_alignment;
@@ -1788,8 +1956,7 @@ int ustctl_recv_reg_msg(int sock,
        if (reg_msg.major != LTTNG_UST_ABI_MAJOR_VERSION) {
                return -LTTNG_UST_ERR_UNSUP_MAJOR;
        }
-
-       return 0;
+       return get_cred(sock, &reg_msg, pid, ppid, uid, gid);
 }
 
 int ustctl_recv_notify(int sock, enum ustctl_notify_cmd *notify_cmd)
@@ -2149,10 +2316,28 @@ int ustctl_reply_register_channel(int sock,
        return 0;
 }
 
+/* Regenerate the statedump. */
+int ustctl_regenerate_statedump(int sock, int handle)
+{
+       struct ustcomm_ust_msg lum;
+       struct ustcomm_ust_reply lur;
+       int ret;
+
+       memset(&lum, 0, sizeof(lum));
+       lum.handle = handle;
+       lum.cmd = LTTNG_UST_SESSION_STATEDUMP;
+       ret = ustcomm_send_app_cmd(sock, &lum, &lur);
+       if (ret)
+               return ret;
+       DBG("Regenerated statedump for handle %u", handle);
+       return 0;
+}
+
 static __attribute__((constructor))
 void ustctl_init(void)
 {
        init_usterr();
+       lttng_ust_getenv_init();        /* Needs init_usterr() to be completed. */
        lttng_ust_clock_init();
        lttng_ring_buffer_metadata_client_init();
        lttng_ring_buffer_client_overwrite_init();
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