| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License as published by the Free |
| 6 | * Software Foundation; only version 2 of the License. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for |
| 11 | * more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along with |
| 14 | * this program; if not, write to the Free Software Foundation, Inc., 59 Temple |
| 15 | * Place - Suite 330, Boston, MA 02111-1307, USA. |
| 16 | */ |
| 17 | |
| 18 | #include <string.h> |
| 19 | #include <unistd.h> |
| 20 | |
| 21 | #include <lttng/lttng.h> |
| 22 | #include <lttng-sessiond-comm.h> |
| 23 | #include <lttngerr.h> |
| 24 | |
| 25 | #include "channel.h" |
| 26 | #include "hashtable.h" |
| 27 | #include "kernel.h" |
| 28 | #include "ust-ctl.h" |
| 29 | #include "utils.h" |
| 30 | |
| 31 | /* |
| 32 | * Return allocated channel attributes. |
| 33 | */ |
| 34 | struct lttng_channel *channel_new_default_attr(int dom) |
| 35 | { |
| 36 | struct lttng_channel *chan; |
| 37 | |
| 38 | chan = zmalloc(sizeof(struct lttng_channel)); |
| 39 | if (chan == NULL) { |
| 40 | perror("zmalloc channel init"); |
| 41 | goto error_alloc; |
| 42 | } |
| 43 | |
| 44 | if (snprintf(chan->name, sizeof(chan->name), "%s", |
| 45 | DEFAULT_CHANNEL_NAME) < 0) { |
| 46 | perror("snprintf default channel name"); |
| 47 | goto error; |
| 48 | } |
| 49 | |
| 50 | chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE; |
| 51 | chan->attr.switch_timer_interval = DEFAULT_CHANNEL_SWITCH_TIMER; |
| 52 | chan->attr.read_timer_interval = DEFAULT_CHANNEL_READ_TIMER; |
| 53 | |
| 54 | switch (dom) { |
| 55 | case LTTNG_DOMAIN_KERNEL: |
| 56 | chan->attr.subbuf_size = DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE; |
| 57 | chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM; |
| 58 | chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT; |
| 59 | break; |
| 60 | case LTTNG_DOMAIN_UST: |
| 61 | case LTTNG_DOMAIN_UST_PID: |
| 62 | chan->attr.subbuf_size = DEFAULT_UST_CHANNEL_SUBBUF_SIZE; |
| 63 | chan->attr.num_subbuf = DEFAULT_UST_CHANNEL_SUBBUF_NUM; |
| 64 | chan->attr.output = DEFAULT_UST_CHANNEL_OUTPUT; |
| 65 | break; |
| 66 | default: |
| 67 | goto error; /* Not implemented */ |
| 68 | } |
| 69 | |
| 70 | return chan; |
| 71 | |
| 72 | error: |
| 73 | free(chan); |
| 74 | error_alloc: |
| 75 | return NULL; |
| 76 | } |
| 77 | |
| 78 | /* |
| 79 | * Disable kernel channel of the kernel session. |
| 80 | */ |
| 81 | int channel_kernel_disable(struct ltt_kernel_session *ksession, |
| 82 | char *channel_name) |
| 83 | { |
| 84 | int ret; |
| 85 | struct ltt_kernel_channel *kchan; |
| 86 | |
| 87 | kchan = trace_kernel_get_channel_by_name(channel_name, ksession); |
| 88 | if (kchan == NULL) { |
| 89 | ret = LTTCOMM_KERN_CHAN_NOT_FOUND; |
| 90 | goto error; |
| 91 | } else if (kchan->enabled == 1) { |
| 92 | ret = kernel_disable_channel(kchan); |
| 93 | if (ret < 0) { |
| 94 | if (ret != EEXIST) { |
| 95 | ret = LTTCOMM_KERN_CHAN_DISABLE_FAIL; |
| 96 | } |
| 97 | goto error; |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | ret = LTTCOMM_OK; |
| 102 | |
| 103 | error: |
| 104 | return ret; |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * Enable kernel channel of the kernel session. |
| 109 | */ |
| 110 | int channel_kernel_enable(struct ltt_kernel_session *ksession, |
| 111 | struct ltt_kernel_channel *kchan) |
| 112 | { |
| 113 | int ret; |
| 114 | |
| 115 | if (kchan->enabled == 0) { |
| 116 | ret = kernel_enable_channel(kchan); |
| 117 | if (ret < 0) { |
| 118 | ret = LTTCOMM_KERN_CHAN_ENABLE_FAIL; |
| 119 | goto error; |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | ret = LTTCOMM_OK; |
| 124 | |
| 125 | error: |
| 126 | return ret; |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Create kernel channel of the kernel session and notify kernel thread. |
| 131 | */ |
| 132 | int channel_kernel_create(struct ltt_kernel_session *ksession, |
| 133 | struct lttng_channel *attr, int kernel_pipe) |
| 134 | { |
| 135 | int ret; |
| 136 | struct lttng_channel *defattr = NULL; |
| 137 | |
| 138 | /* Creating channel attributes if needed */ |
| 139 | if (attr == NULL) { |
| 140 | defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL); |
| 141 | if (defattr == NULL) { |
| 142 | ret = LTTCOMM_FATAL; |
| 143 | goto error; |
| 144 | } |
| 145 | attr = defattr; |
| 146 | } |
| 147 | |
| 148 | /* Channel not found, creating it */ |
| 149 | ret = kernel_create_channel(ksession, attr, ksession->trace_path); |
| 150 | if (ret < 0) { |
| 151 | ret = LTTCOMM_KERN_CHAN_FAIL; |
| 152 | goto error; |
| 153 | } |
| 154 | |
| 155 | /* Notify kernel thread that there is a new channel */ |
| 156 | ret = notify_thread_pipe(kernel_pipe); |
| 157 | if (ret < 0) { |
| 158 | ret = LTTCOMM_FATAL; |
| 159 | goto error; |
| 160 | } |
| 161 | |
| 162 | ret = LTTCOMM_OK; |
| 163 | error: |
| 164 | free(defattr); |
| 165 | return ret; |
| 166 | } |