| 1 | /* |
| 2 | * event-notifier-notification.c |
| 3 | * |
| 4 | * Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com> |
| 5 | * |
| 6 | * This library is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU Lesser General Public |
| 8 | * License as published by the Free Software Foundation; only |
| 9 | * version 2.1 of the License. |
| 10 | * |
| 11 | * This library is distributed in the hope that it will be useful, |
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * Lesser General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU Lesser General Public |
| 17 | * License along with this library; if not, write to the Free Software |
| 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 19 | */ |
| 20 | |
| 21 | #define _LGPL_SOURCE |
| 22 | |
| 23 | #include <assert.h> |
| 24 | #include <byteswap.h> |
| 25 | #include <errno.h> |
| 26 | #include <lttng/ust-events.h> |
| 27 | #include <usterr-signal-safe.h> |
| 28 | |
| 29 | #include "../libmsgpack/msgpack.h" |
| 30 | #include "lttng-bytecode.h" |
| 31 | #include "share.h" |
| 32 | |
| 33 | static |
| 34 | void capture_enum(struct lttng_msgpack_writer *writer, |
| 35 | struct lttng_interpreter_output *output) __attribute__ ((unused)); |
| 36 | static |
| 37 | void capture_enum(struct lttng_msgpack_writer *writer, |
| 38 | struct lttng_interpreter_output *output) |
| 39 | { |
| 40 | lttng_msgpack_begin_map(writer, 2); |
| 41 | lttng_msgpack_write_str(writer, "type"); |
| 42 | lttng_msgpack_write_str(writer, "enum"); |
| 43 | |
| 44 | lttng_msgpack_write_str(writer, "value"); |
| 45 | |
| 46 | switch (output->type) { |
| 47 | case LTTNG_INTERPRETER_TYPE_SIGNED_ENUM: |
| 48 | lttng_msgpack_write_signed_integer(writer, output->u.s); |
| 49 | break; |
| 50 | case LTTNG_INTERPRETER_TYPE_UNSIGNED_ENUM: |
| 51 | lttng_msgpack_write_signed_integer(writer, output->u.u); |
| 52 | break; |
| 53 | default: |
| 54 | abort(); |
| 55 | } |
| 56 | |
| 57 | lttng_msgpack_end_map(writer); |
| 58 | } |
| 59 | |
| 60 | static |
| 61 | int64_t capture_sequence_element_signed(uint8_t *ptr, |
| 62 | const struct lttng_integer_type *type) |
| 63 | { |
| 64 | int64_t value; |
| 65 | unsigned int size = type->size; |
| 66 | bool byte_order_reversed = type->reverse_byte_order; |
| 67 | |
| 68 | switch (size) { |
| 69 | case 8: |
| 70 | value = *ptr; |
| 71 | break; |
| 72 | case 16: |
| 73 | { |
| 74 | int16_t tmp; |
| 75 | tmp = *(int16_t *) ptr; |
| 76 | if (byte_order_reversed) |
| 77 | tmp = bswap_16(tmp); |
| 78 | |
| 79 | value = tmp; |
| 80 | break; |
| 81 | } |
| 82 | case 32: |
| 83 | { |
| 84 | int32_t tmp; |
| 85 | tmp = *(int32_t *) ptr; |
| 86 | if (byte_order_reversed) |
| 87 | tmp = bswap_32(tmp); |
| 88 | |
| 89 | value = tmp; |
| 90 | break; |
| 91 | } |
| 92 | case 64: |
| 93 | { |
| 94 | int64_t tmp; |
| 95 | tmp = *(int64_t *) ptr; |
| 96 | if (byte_order_reversed) |
| 97 | tmp = bswap_64(tmp); |
| 98 | |
| 99 | value = tmp; |
| 100 | break; |
| 101 | } |
| 102 | default: |
| 103 | abort(); |
| 104 | } |
| 105 | |
| 106 | return value; |
| 107 | } |
| 108 | |
| 109 | static |
| 110 | uint64_t capture_sequence_element_unsigned(uint8_t *ptr, |
| 111 | const struct lttng_integer_type *type) |
| 112 | { |
| 113 | uint64_t value; |
| 114 | unsigned int size = type->size; |
| 115 | bool byte_order_reversed = type->reverse_byte_order; |
| 116 | |
| 117 | switch (size) { |
| 118 | case 8: |
| 119 | value = *ptr; |
| 120 | break; |
| 121 | case 16: |
| 122 | { |
| 123 | uint16_t tmp; |
| 124 | tmp = *(uint16_t *) ptr; |
| 125 | if (byte_order_reversed) |
| 126 | tmp = bswap_16(tmp); |
| 127 | |
| 128 | value = tmp; |
| 129 | break; |
| 130 | } |
| 131 | case 32: |
| 132 | { |
| 133 | uint32_t tmp; |
| 134 | tmp = *(uint32_t *) ptr; |
| 135 | if (byte_order_reversed) |
| 136 | tmp = bswap_32(tmp); |
| 137 | |
| 138 | value = tmp; |
| 139 | break; |
| 140 | } |
| 141 | case 64: |
| 142 | { |
| 143 | uint64_t tmp; |
| 144 | tmp = *(uint64_t *) ptr; |
| 145 | if (byte_order_reversed) |
| 146 | tmp = bswap_64(tmp); |
| 147 | |
| 148 | value = tmp; |
| 149 | break; |
| 150 | } |
| 151 | default: |
| 152 | abort(); |
| 153 | } |
| 154 | |
| 155 | return value; |
| 156 | } |
| 157 | |
| 158 | static |
| 159 | void capture_sequence(struct lttng_msgpack_writer *writer, |
| 160 | struct lttng_interpreter_output *output) __attribute__ ((unused)); |
| 161 | static |
| 162 | void capture_sequence(struct lttng_msgpack_writer *writer, |
| 163 | struct lttng_interpreter_output *output) |
| 164 | { |
| 165 | const struct lttng_integer_type *integer_type; |
| 166 | const struct lttng_type *nested_type; |
| 167 | uint8_t *ptr; |
| 168 | bool signedness; |
| 169 | int i; |
| 170 | |
| 171 | lttng_msgpack_begin_array(writer, output->u.sequence.nr_elem); |
| 172 | |
| 173 | ptr = (uint8_t *) output->u.sequence.ptr; |
| 174 | nested_type = output->u.sequence.nested_type; |
| 175 | switch (nested_type->atype) { |
| 176 | case atype_integer: |
| 177 | integer_type = &nested_type->u.integer; |
| 178 | break; |
| 179 | case atype_enum: |
| 180 | /* Treat enumeration as an integer. */ |
| 181 | integer_type = &nested_type->u.enum_nestable.container_type->u.integer; |
| 182 | break; |
| 183 | default: |
| 184 | /* Capture of array of non-integer are not supported. */ |
| 185 | abort(); |
| 186 | } |
| 187 | signedness = integer_type->signedness; |
| 188 | for (i = 0; i < output->u.sequence.nr_elem; i++) { |
| 189 | if (signedness) { |
| 190 | lttng_msgpack_write_signed_integer(writer, |
| 191 | capture_sequence_element_signed(ptr, integer_type)); |
| 192 | } else { |
| 193 | lttng_msgpack_write_unsigned_integer(writer, |
| 194 | capture_sequence_element_unsigned(ptr, integer_type)); |
| 195 | } |
| 196 | |
| 197 | /* |
| 198 | * We assume that alignment is smaller or equal to the size. |
| 199 | * This currently holds true but if it changes in the future, |
| 200 | * we will want to change the pointer arithmetics below to |
| 201 | * take into account that the next element might be further |
| 202 | * away. |
| 203 | */ |
| 204 | assert(integer_type->alignment <= integer_type->size); |
| 205 | |
| 206 | /* Size is in number of bits. */ |
| 207 | ptr += (integer_type->size / CHAR_BIT) ; |
| 208 | } |
| 209 | |
| 210 | lttng_msgpack_end_array(writer); |
| 211 | } |
| 212 | |
| 213 | void lttng_event_notifier_notification_send( |
| 214 | struct lttng_event_notifier *event_notifier) |
| 215 | { |
| 216 | /* |
| 217 | * We want this write to be atomic AND non-blocking, meaning that we |
| 218 | * want to write either everything OR nothing. |
| 219 | * According to `pipe(7)`, writes that are smaller that the `PIPE_BUF` |
| 220 | * value must be atomic, so we assert that the message we send is less |
| 221 | * than PIPE_BUF. |
| 222 | */ |
| 223 | struct lttng_ust_event_notifier_notification notif; |
| 224 | ssize_t ret; |
| 225 | |
| 226 | assert(event_notifier); |
| 227 | assert(event_notifier->group); |
| 228 | assert(sizeof(notif) <= PIPE_BUF); |
| 229 | |
| 230 | notif.token = event_notifier->user_token; |
| 231 | |
| 232 | ret = patient_write(event_notifier->group->notification_fd, ¬if, |
| 233 | sizeof(notif)); |
| 234 | if (ret == -1) { |
| 235 | if (errno == EAGAIN) { |
| 236 | DBG("Cannot send event notifier notification without blocking: %s", |
| 237 | strerror(errno)); |
| 238 | } else { |
| 239 | DBG("Error to sending event notifier notification: %s", |
| 240 | strerror(errno)); |
| 241 | abort(); |
| 242 | } |
| 243 | } |
| 244 | } |