Elia Battiston | 4750d3c | 2022-07-14 13:24:56 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2022-present Open Networking Foundation |
| 3 | |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package sysrepo |
| 18 | |
| 19 | //#cgo LDFLAGS: -lsysrepo -lyang -Wl,--allow-multiple-definition |
| 20 | //#include "plugin.c" |
| 21 | import "C" |
| 22 | import ( |
| 23 | "context" |
| 24 | "fmt" |
| 25 | "unsafe" |
| 26 | |
| 27 | "github.com/opencord/voltha-lib-go/v7/pkg/log" |
| 28 | "github.com/opencord/voltha-northbound-bbf-adapter/internal/core" |
| 29 | ) |
| 30 | |
| 31 | //srErrorMsg provides a description of a sysrepo error code |
| 32 | func srErrorMsg(code C.int) string { |
| 33 | return C.GoString(C.sr_strerror(code)) |
| 34 | } |
| 35 | |
| 36 | //lyErrorMsg provides the last libyang error message |
| 37 | func lyErrorMsg(ly_ctx *C.ly_ctx) string { |
| 38 | lyErrString := C.ly_errmsg(ly_ctx) |
| 39 | defer freeCString(lyErrString) |
| 40 | |
| 41 | return C.GoString(lyErrString) |
| 42 | } |
| 43 | |
| 44 | func freeCString(str *C.char) { |
| 45 | if str != nil { |
| 46 | C.free(unsafe.Pointer(str)) |
| 47 | str = nil |
| 48 | } |
| 49 | } |
| 50 | |
| 51 | //Creates a new libyang nodes tree from a set of new paths. |
| 52 | //The tree must bee manually freed after its use with C.lyd_free_all or |
| 53 | //an equivalent function |
| 54 | func createYangTree(ctx context.Context, session *C.sr_session_ctx_t, items []core.YangItem) (*C.lyd_node, error) { |
| 55 | if len(items) == 0 { |
| 56 | return nil, fmt.Errorf("no-items") |
| 57 | } |
| 58 | |
| 59 | conn := C.sr_session_get_connection(session) |
| 60 | if conn == nil { |
| 61 | return nil, fmt.Errorf("null-connection") |
| 62 | } |
| 63 | |
| 64 | //libyang context |
| 65 | ly_ctx := C.sr_acquire_context(conn) |
| 66 | if ly_ctx == nil { |
| 67 | return nil, fmt.Errorf("null-libyang-context") |
| 68 | } |
| 69 | defer C.sr_release_context(conn) |
| 70 | |
| 71 | //Create parent node |
| 72 | parentPath := C.CString(items[0].Path) |
| 73 | parentValue := C.CString(items[0].Value) |
| 74 | |
| 75 | var parent *C.lyd_node |
| 76 | lyErr := C.lyd_new_path(nil, ly_ctx, parentPath, parentValue, 0, &parent) |
| 77 | if lyErr != C.LY_SUCCESS { |
| 78 | err := fmt.Errorf("libyang-new-path-failed: %d %s", lyErr, lyErrorMsg(ly_ctx)) |
| 79 | return nil, err |
| 80 | } |
| 81 | logger.Debugw(ctx, "creating-yang-item", log.Fields{"item": items[0]}) |
| 82 | |
| 83 | freeCString(parentPath) |
| 84 | freeCString(parentValue) |
| 85 | |
| 86 | //Add remaining nodes |
| 87 | for _, item := range items[1:] { |
| 88 | logger.Debugw(ctx, "creating-yang-item", log.Fields{"item": item}) |
| 89 | |
| 90 | path := C.CString(item.Path) |
| 91 | value := C.CString(item.Value) |
| 92 | |
| 93 | lyErr := C.lyd_new_path(parent, ly_ctx, path, value, 0, nil) |
| 94 | if lyErr != C.LY_SUCCESS { |
| 95 | freeCString(path) |
| 96 | freeCString(value) |
| 97 | |
| 98 | //Free the partially created tree |
| 99 | C.lyd_free_all(parent) |
| 100 | |
| 101 | err := fmt.Errorf("libyang-new-path-failed: %d %s", lyErr, lyErrorMsg(ly_ctx)) |
| 102 | |
| 103 | return nil, err |
| 104 | } |
| 105 | |
| 106 | freeCString(path) |
| 107 | freeCString(value) |
| 108 | } |
| 109 | |
| 110 | return parent, nil |
| 111 | } |
| 112 | |
| 113 | //Creates a set of new paths under an existing libyang tree parent node |
| 114 | func updateYangTree(ctx context.Context, session *C.sr_session_ctx_t, parent **C.lyd_node, items []core.YangItem) error { |
| 115 | if len(items) == 0 { |
| 116 | //Nothing to do |
| 117 | return nil |
| 118 | } |
| 119 | |
| 120 | conn := C.sr_session_get_connection(session) |
| 121 | if conn == nil { |
| 122 | return fmt.Errorf("null-connection") |
| 123 | } |
| 124 | |
| 125 | //libyang context |
| 126 | ly_ctx := C.sr_acquire_context(conn) |
| 127 | if ly_ctx == nil { |
| 128 | return fmt.Errorf("null-libyang-context") |
| 129 | } |
| 130 | defer C.sr_release_context(conn) |
| 131 | |
| 132 | for _, item := range items { |
| 133 | logger.Debugw(ctx, "updating-yang-item", log.Fields{"item": item}) |
| 134 | |
| 135 | path := C.CString(item.Path) |
| 136 | value := C.CString(item.Value) |
| 137 | |
Elia Battiston | a133364 | 2022-07-27 12:17:24 +0000 | [diff] [blame] | 138 | lyErr := C.lyd_new_path(*parent, ly_ctx, path, value, C.LYD_NEW_PATH_UPDATE, nil) |
Elia Battiston | 4750d3c | 2022-07-14 13:24:56 +0000 | [diff] [blame] | 139 | if lyErr != C.LY_SUCCESS { |
| 140 | freeCString(path) |
| 141 | freeCString(value) |
| 142 | |
| 143 | err := fmt.Errorf("libyang-new-path-failed: %d %s", lyErr, lyErrorMsg(ly_ctx)) |
| 144 | |
| 145 | return err |
| 146 | } |
| 147 | |
| 148 | freeCString(path) |
| 149 | freeCString(value) |
| 150 | } |
| 151 | |
| 152 | return nil |
| 153 | } |
| 154 | |
| 155 | //Merges the content of a yang tree with the content of the datastore. |
| 156 | //The target datastore is the one on which the session has been created |
| 157 | func editDatastore(ctx context.Context, session *C.sr_session_ctx_t, editsTree *C.lyd_node) error { |
| 158 | errCode := C.sr_edit_batch(session, editsTree, C.mergeOperation) |
| 159 | if errCode != C.SR_ERR_OK { |
| 160 | err := fmt.Errorf("failed-to-edit-datastore") |
| 161 | logger.Errorw(ctx, err.Error(), log.Fields{"errCode": errCode, "errMsg": srErrorMsg(errCode)}) |
| 162 | return err |
| 163 | } |
| 164 | |
| 165 | errCode = C.sr_apply_changes(session, 0) |
| 166 | if errCode != C.SR_ERR_OK { |
| 167 | err := fmt.Errorf("failed-to-apply-datastore-changes") |
| 168 | logger.Errorw(ctx, err.Error(), log.Fields{"errCode": errCode, "errMsg": srErrorMsg(errCode)}) |
| 169 | return err |
| 170 | } |
| 171 | |
| 172 | return nil |
| 173 | } |
Elia Battiston | a133364 | 2022-07-27 12:17:24 +0000 | [diff] [blame] | 174 | |
| 175 | type YangChange struct { |
| 176 | Path string |
| 177 | Value string |
| 178 | Operation C.sr_change_oper_t |
| 179 | /* Operation values: |
| 180 | SR_OP_CREATED |
| 181 | SR_OP_MODIFIED |
| 182 | SR_OP_DELETED |
| 183 | SR_OP_MOVED |
| 184 | */ |
| 185 | } |
| 186 | |
| 187 | //Provides a list of the changes occured under a specific path |
| 188 | //Should only be used on the session from an sr_module_change_subscribe callback |
| 189 | func getChangesList(ctx context.Context, editSession *C.sr_session_ctx_t, path string) ([]YangChange, error) { |
| 190 | result := []YangChange{} |
| 191 | |
| 192 | changesPath := C.CString(path) |
| 193 | defer freeCString(changesPath) |
| 194 | |
| 195 | var changesIterator *C.sr_change_iter_t |
| 196 | errCode := C.sr_get_changes_iter(editSession, changesPath, &changesIterator) |
| 197 | if errCode != C.SR_ERR_OK { |
| 198 | return nil, fmt.Errorf("cannot-get-iterator: %d %s", errCode, srErrorMsg(errCode)) |
| 199 | } |
| 200 | defer C.sr_free_change_iter(changesIterator) |
| 201 | |
| 202 | //Iterate over the changes |
| 203 | var operation C.sr_change_oper_t |
| 204 | var prevValue, prevList *C.char |
| 205 | var prevDefault C.int |
| 206 | |
| 207 | var node *C.lyd_node |
| 208 | defer C.lyd_free_all(node) |
| 209 | |
| 210 | errCode = C.sr_get_change_tree_next(editSession, changesIterator, &operation, &node, &prevValue, &prevList, &prevDefault) |
| 211 | for errCode != C.SR_ERR_NOT_FOUND { |
| 212 | if errCode != C.SR_ERR_OK { |
| 213 | return nil, fmt.Errorf("next-change-error: %d %s", errCode, srErrorMsg(errCode)) |
| 214 | } |
| 215 | |
| 216 | currentChange := YangChange{} |
| 217 | currentChange.Operation = operation |
| 218 | |
| 219 | nodePath := C.lyd_path(node, C.LYD_PATH_STD, nil, 0) |
| 220 | if nodePath == nil { |
| 221 | return nil, fmt.Errorf("cannot-get-change-path") |
| 222 | } |
| 223 | currentChange.Path = C.GoString(nodePath) |
| 224 | freeCString(nodePath) |
| 225 | |
| 226 | nodeValue := C.lyd_get_value(node) |
| 227 | if nodeValue != nil { |
| 228 | currentChange.Value = C.GoString(nodeValue) |
| 229 | result = append(result, currentChange) |
| 230 | } |
| 231 | |
| 232 | errCode = C.sr_get_change_tree_next(editSession, changesIterator, &operation, &node, &prevValue, &prevList, &prevDefault) |
| 233 | } |
| 234 | |
| 235 | return result, nil |
| 236 | } |
| 237 | |
| 238 | //Verify that only one change occured under the specified path, and return its value |
| 239 | //Should only be used on the session from an sr_module_change_subscribe callback |
| 240 | func getSingleChangeValue(ctx context.Context, session *C.sr_session_ctx_t, path string) (string, error) { |
| 241 | changesList, err := getChangesList(ctx, session, path) |
| 242 | if err != nil { |
| 243 | return "", err |
| 244 | } |
| 245 | |
| 246 | if len(changesList) != 1 { |
| 247 | logger.Errorw(ctx, "unexpected-number-of-yang-changes", log.Fields{ |
| 248 | "changes": changesList, |
| 249 | }) |
| 250 | return "", fmt.Errorf("unexpected-number-of-yang-changes") |
| 251 | } |
| 252 | |
| 253 | return changesList[0].Value, nil |
| 254 | } |
| 255 | |
| 256 | //Get the value of a leaf from the datastore |
| 257 | //The target datastore is the one on which the session has been created |
| 258 | func getDatastoreLeafValue(ctx context.Context, session *C.sr_session_ctx_t, path string) (string, error) { |
| 259 | cPath := C.CString(path) |
| 260 | defer freeCString(cPath) |
| 261 | |
| 262 | var data *C.sr_data_t |
| 263 | defer C.sr_release_data(data) |
| 264 | |
| 265 | errCode := C.sr_get_subtree(session, cPath, 0, &data) |
| 266 | if errCode != C.SR_ERR_OK { |
| 267 | return "", fmt.Errorf("cannot-get-data-from-datastore: %d %s", errCode, srErrorMsg(errCode)) |
| 268 | } |
| 269 | |
| 270 | if data == nil { |
| 271 | return "", fmt.Errorf("no-data-found-for-path: %s", path) |
| 272 | } |
| 273 | |
| 274 | nodeValue := C.lyd_get_value(data.tree) |
| 275 | if nodeValue == nil { |
| 276 | return "", fmt.Errorf("cannot-get-value-from-data: %s", path) |
| 277 | } |
| 278 | |
| 279 | return C.GoString(nodeValue), nil |
| 280 | } |