diff options
author | Thomas Tuttle <ttuttle@google.com> | 2010-07-19 10:05:44 -0700 |
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committer | Thomas Tuttle <ttuttle@google.com> | 2010-08-02 16:37:07 -0700 |
commit | 2045e6e39d6dbfed1e46c333c2910c66e788cd36 (patch) | |
tree | 0a6056c82d7111bbd00eb8456963787670fb01d6 /libublock | |
parent | e0fa0392204a24f086a2508b043c3962983b9483 (diff) | |
download | extras-2045e6e39d6dbfed1e46c333c2910c66e788cd36.tar.gz |
libublock: Userspace library for ublock
Change-Id: I0bbeb07095f8376084d982ff49ac0d4793c1195f
Diffstat (limited to 'libublock')
-rw-r--r-- | libublock/Android.mk | 24 | ||||
-rw-r--r-- | libublock/MODULE_LICENSE_APACHE2 | 0 | ||||
-rw-r--r-- | libublock/NOTICE | 190 | ||||
-rw-r--r-- | libublock/include/ublock/ublock.h | 72 | ||||
-rw-r--r-- | libublock/ublock.c | 430 |
5 files changed, 716 insertions, 0 deletions
diff --git a/libublock/Android.mk b/libublock/Android.mk new file mode 100644 index 00000000..6c5b208b --- /dev/null +++ b/libublock/Android.mk @@ -0,0 +1,24 @@ +# Copyright (C) 2010 The Android Open Source Project +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +LOCAL_PATH := $(call my-dir) +include $(CLEAR_VARS) + +LOCAL_MODULE := libublock + +LOCAL_SRC_FILES := ublock.c + +LOCAL_C_INCLUDES := $(LOCAL_PATH)/include + +include $(BUILD_SHARED_LIBRARY) diff --git a/libublock/MODULE_LICENSE_APACHE2 b/libublock/MODULE_LICENSE_APACHE2 new file mode 100644 index 00000000..e69de29b --- /dev/null +++ b/libublock/MODULE_LICENSE_APACHE2 diff --git a/libublock/NOTICE b/libublock/NOTICE new file mode 100644 index 00000000..c5b1efa7 --- /dev/null +++ b/libublock/NOTICE @@ -0,0 +1,190 @@ + + Copyright (c) 2005-2008, The Android Open Source Project + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + + + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. For the purposes of this definition, + "control" means (i) the power, direct or indirect, to cause the + direction or management of such entity, whether by contract or + otherwise, or (ii) ownership of fifty percent (50%) or more of the + outstanding shares, or (iii) beneficial ownership of such entity. + + "You" (or "Your") shall mean an individual or Legal Entity + exercising permissions granted by this License. + + "Source" form shall mean the preferred form for making modifications, + including but not limited to software source code, documentation + source, and configuration files. + + "Object" form shall mean any form resulting from mechanical + transformation or translation of a Source form, including but + not limited to compiled object code, generated documentation, + and conversions to other media types. + + "Work" shall mean the work of authorship, whether in Source or + Object form, made available under the License, as indicated by a + copyright notice that is included in or attached to the work + (an example is provided in the Appendix below). + + "Derivative Works" shall mean any work, whether in Source or Object + form, that is based on (or derived from) the Work and for which the + editorial revisions, annotations, elaborations, or other modifications + represent, as a whole, an original work of authorship. For the purposes + of this License, Derivative Works shall not include works that remain + separable from, or merely link (or bind by name) to the interfaces of, + the Work and Derivative Works thereof. + + "Contribution" shall mean any work of authorship, including + the original version of the Work and any modifications or additions + to that Work or Derivative Works thereof, that is intentionally + submitted to Licensor for inclusion in the Work by the copyright owner + or by an individual or Legal Entity authorized to submit on behalf of + the copyright owner. For the purposes of this definition, "submitted" + means any form of electronic, verbal, or written communication sent + to the Licensor or its representatives, including but not limited to + communication on electronic mailing lists, source code control systems, + and issue tracking systems that are managed by, or on behalf of, the + Licensor for the purpose of discussing and improving the Work, but + excluding communication that is conspicuously marked or otherwise + designated in writing by the copyright owner as "Not a Contribution." + + "Contributor" shall mean Licensor and any individual or Legal Entity + on behalf of whom a Contribution has been received by Licensor and + subsequently incorporated within the Work. + + 2. Grant of Copyright License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + copyright license to reproduce, prepare Derivative Works of, + publicly display, publicly perform, sublicense, and distribute the + Work and such Derivative Works in Source or Object form. + + 3. Grant of Patent License. Subject to the terms and conditions of + this License, each Contributor hereby grants to You a perpetual, + worldwide, non-exclusive, no-charge, royalty-free, irrevocable + (except as stated in this section) patent license to make, have made, + use, offer to sell, sell, import, and otherwise transfer the Work, + where such license applies only to those patent claims licensable + by such Contributor that are necessarily infringed by their + Contribution(s) alone or by combination of their Contribution(s) + with the Work to which such Contribution(s) was submitted. If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + + 4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. 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Unless required by applicable law or + agreed to in writing, Licensor provides the Work (and each + Contributor provides its Contributions) on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied, including, without limitation, any warranties or conditions + of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A + PARTICULAR PURPOSE. You are solely responsible for determining the + appropriateness of using or redistributing the Work and assume any + risks associated with Your exercise of permissions under this License. + + 8. Limitation of Liability. In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + + 9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + diff --git a/libublock/include/ublock/ublock.h b/libublock/include/ublock/ublock.h new file mode 100644 index 00000000..5b691b0e --- /dev/null +++ b/libublock/include/ublock/ublock.h @@ -0,0 +1,72 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef UBLOCK_UBLOCK_H +#define UBLOCK_UBLOCK_H + +#include <stdint.h> +#include <sys/types.h> + +#define UBLOCK_VERSION 0 + +struct ublock_ctx; + +struct ublock_ops { + int (*read)(char *buf, uint64_t length, uint64_t offset); + int (*write)(const char *buf, uint64_t length, uint64_t offset); +}; + +/* + * Initializes a ublock block device. + * + * May call your read and write functions as the kernel scans partition + * tables. Will return once the kernel has finished adding the block device. + * + * Returns 0 on success, + * -ENOMEM if we ran out of memory, + * -ENOENT if the kernel appears to lack ublock support, and + * -EPROTO if the kernel did something unexpected. + */ +int ublock_init(struct ublock_ctx **ub, struct ublock_ops *ops, uint64_t size); + +/* + * Returns the index of a ublock block device. + * + * Returns -EFAULT if the context is NULL, + * -EINVAL if the context is invalid. + */ +int ublock_index(struct ublock_ctx *ub); + +/* + * Runs a loop waiting for ublock requests and calling the ops callbacks. + * + * Returns 0 if the loop was stopped by ublock_stop, + * -EPROTO if the loop was stopped by a protocol error, + */ +int ublock_run(struct ublock_ctx *ub); + +/* + * Stops ublock_run, if it is running. Should be called from one of the ops + * callbacks. + */ +void ublock_stop(struct ublock_ctx *ub); + +/* + * Destroys a ublock block device. + */ +void ublock_destroy(struct ublock_ctx *ub); + +#endif diff --git a/libublock/ublock.c b/libublock/ublock.c new file mode 100644 index 00000000..c2627b1e --- /dev/null +++ b/libublock/ublock.c @@ -0,0 +1,430 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/ublock.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <ublock/ublock.h> + +#define CONTROL_FILE "/dev/ublockctl" + +struct ublock_ctx { + struct ublock_ops *ops; + + uint32_t index; + uint64_t size; + uint32_t max_buf; + + char *in_buf; + char *out_buf; + + int flags; + int fd; + int fails; +}; + +#define CTX_INITED 0x1 +#define CTX_READY 0x2 +#define CTX_RUNNING 0x4 + +#define MAX_BUF 65536 + +#define MAX_FAILURES 10 + +static inline void ublock_succeed(struct ublock_ctx *ub_ctx) +{ + assert(ub_ctx); + + ub_ctx->fails = 0; +} + +static void ublock_fail(struct ublock_ctx *ub_ctx) +{ + assert(ub_ctx); + + ub_ctx->fails++; + if (ub_ctx->fails > MAX_FAILURES) + ublock_stop(ub_ctx); +} + +static int ublock_handle_init(struct ublock_ctx *ub_ctx, + const void *in, size_t in_len, + void *out, size_t *out_len) +{ + const struct ublock_init_in *in_h; + struct ublock_init_out *out_h; + + assert(ub_ctx); + assert(in); + assert(out); + + if (in_len != sizeof(*in_h)) + return -EPROTO; + + in_h = (const struct ublock_init_in *)in; + + if (in_h->version != UBLOCK_VERSION) + return -EPROTO; + + out_h = (struct ublock_init_out *)out; + out_h->version = UBLOCK_VERSION; + out_h->size = ub_ctx->size; + if (in_h->max_buf < MAX_BUF) + ub_ctx->max_buf = in_h->max_buf; + else + ub_ctx->max_buf = MAX_BUF; + out_h->max_buf = ub_ctx->max_buf; + + *out_len = sizeof(*out_h); + + ub_ctx->index = in_h->index; + ub_ctx->flags |= CTX_INITED; + + return 0; +} + +static int ublock_handle_ready(struct ublock_ctx *ub_ctx, + const void *in, size_t in_len, + void *out, size_t *out_len) +{ + struct ublock_ready_out *out_h; + + assert(ub_ctx); + assert(in); + assert(out); + + if (in_len != sizeof(struct ublock_ready_in)) + return -EPROTO; + + *out_len = sizeof(struct ublock_ready_out); + + ub_ctx->flags |= CTX_READY; + + return 0; +} + +static int ublock_handle_read(struct ublock_ctx *ub_ctx, + const void *in, size_t in_len, + void *out, size_t *out_len) +{ + const struct ublock_read_in *in_h; + struct ublock_read_out *out_h; + char *out_buf; + + assert(ub_ctx); + assert(in); + assert(out); + + if (in_len != sizeof(*in_h)) + return -EPROTO; + + in_h = (const struct ublock_read_in *)in; + + out_h = (struct ublock_read_out *)out; + out_buf = (char *)(out_h + 1); + + out_h->status = (ub_ctx->ops->read)(out_buf, in_h->length, in_h->offset); + + if (out_h->status >= 0) + *out_len = sizeof(*out_h) + in_h->length; + else + *out_len = sizeof(*out_h); + + return 0; +} + +static int ublock_handle_write(struct ublock_ctx *ub_ctx, + const void *in, size_t in_len, + void *out, size_t *out_len) +{ + const struct ublock_write_in *in_h; + const char *in_buf; + struct ublock_write_out *out_h; + + assert(ub_ctx); + assert(in); + assert(out); + + if (in_len < sizeof(*in_h)) + return -EPROTO; + + in_h = (const struct ublock_write_in *)in; + in_buf = (const char*)(in_h + 1); + + out_h = (struct ublock_write_out *)out; + *out_len = sizeof(*out_h); + + out_h->status = (ub_ctx->ops->write)(in_buf, in_h->length, in_h->offset); + + return 0; +} + +static int ublock_handle_request(struct ublock_ctx *ub_ctx, + const void *in, size_t in_len, + void *out, size_t *out_len) +{ + const struct ublock_in_header *in_h; + const void *in_buf; + size_t in_buf_len; + + struct ublock_out_header *out_h; + void *out_buf; + size_t out_buf_len; + + int result; + int (*handle_fn)(struct ublock_ctx *, const void *, size_t, void *, size_t *); + + assert(ub_ctx); + assert(in); + assert(out); + + if (in_len < sizeof(*in_h)) + return -EPROTO; + + in_h = (const struct ublock_in_header *)in; + in_buf = in_h + 1; + in_buf_len = in_len - sizeof(*in_h); + + out_h = (struct ublock_out_header *)out; + out_buf = out_h + 1; + + switch (in_h->opcode) { + case UBLOCK_INIT_IN: + out_h->opcode = UBLOCK_INIT_OUT; + handle_fn = &ublock_handle_init; + break; + case UBLOCK_READY_IN: + out_h->opcode = UBLOCK_READY_OUT; + handle_fn = &ublock_handle_ready; + break; + case UBLOCK_READ_IN: + out_h->opcode = UBLOCK_READ_OUT; + handle_fn = &ublock_handle_read; + break; + case UBLOCK_WRITE_IN: + out_h->opcode = UBLOCK_WRITE_OUT; + handle_fn = &ublock_handle_write; + break; + default: + return -EPROTO; + } + + out_h->seq = in_h->seq; + result = (handle_fn)(ub_ctx, in_buf, in_buf_len, out_buf, &out_buf_len); + *out_len = sizeof(*out_h) + out_buf_len; + + return result; +} + +static int ublock_do_request(struct ublock_ctx *ub_ctx, + void *in_buf, size_t in_size, + void *out_buf, size_t out_size) +{ + size_t out_len; + ssize_t in_len, out_wrote; + int result; + + assert(ub_ctx); + assert(in_buf); + assert(out_buf); + + in_len = read(ub_ctx->fd, in_buf, in_size); + if (in_len < 0) + return -EPROTO; + + result = ublock_handle_request(ub_ctx, in_buf, in_len, out_buf, &out_len); + + assert(out_len <= out_size); + + out_wrote = write(ub_ctx->fd, out_buf, out_len); + + if (out_wrote < out_len) + return -EPROTO; + + if (result) + ublock_fail(ub_ctx); + else + ublock_succeed(ub_ctx); + + return result; +} + +#define EXIT_READY 1 +#define EXIT_STOPPED 2 +#define EXIT_FAIL 4 + +static int ublock_loop(struct ublock_ctx *ub_ctx, int exit_cond) +{ + size_t in_len, out_len; + int result; + + result = 0; + while (((exit_cond & EXIT_READY) && (!(ub_ctx->flags & CTX_READY))) || + ((exit_cond & EXIT_STOPPED) && (ub_ctx->flags & CTX_RUNNING)) || + ((exit_cond & EXIT_FAIL) && (result))) { + result = ublock_do_request(ub_ctx, + ub_ctx->in_buf, ub_ctx->max_buf, + ub_ctx->out_buf, ub_ctx->max_buf); + if (result) + return result; + } + + return 0; +} + +int ublock_run(struct ublock_ctx *ub_ctx) +{ + if (!ub_ctx) + return -EFAULT; + + if (!(ub_ctx->flags & CTX_INITED)) + return -EINVAL; + + ub_ctx->flags |= CTX_RUNNING; + ublock_loop(ub_ctx, EXIT_STOPPED); + + return 0; +} + +void ublock_stop(struct ublock_ctx *ub_ctx) +{ + if (!ub_ctx) + return; + + if (!(ub_ctx->flags & CTX_INITED)) + return; + + ub_ctx->flags &= ~CTX_RUNNING; +} + +int ublock_index(struct ublock_ctx *ub_ctx) +{ + if (!ub_ctx) + return -EFAULT; + + if (!(ub_ctx->flags & CTX_INITED)) + return -EINVAL; + + return ub_ctx->index; +} + +static inline size_t ublock_init_buf_size(void) +{ + size_t in_size = sizeof(struct ublock_in_header) + + sizeof(struct ublock_init_in); + size_t out_size = sizeof(struct ublock_out_header) + + sizeof(struct ublock_init_out); + + return (in_size > out_size) ? in_size : out_size; +} + +int ublock_init(struct ublock_ctx **ub_ctx_out, struct ublock_ops *ops, + uint64_t dev_size) +{ + struct ublock_ctx *ub_ctx; + char *in_buf, *out_buf; + size_t size; + int result; + + if (!ub_ctx_out || !ops) + return -EFAULT; + + in_buf = out_buf = NULL; + + ub_ctx = malloc(sizeof(struct ublock_ctx)); + if (!ub_ctx) { + result = -ENOMEM; + goto error; + } + + size = ublock_init_buf_size(); + in_buf = malloc(size); + out_buf = malloc(size); + if (!(in_buf && out_buf)) { + result = -ENOMEM; + goto error; + } + + ub_ctx->ops = ops; + ub_ctx->size = dev_size; + ub_ctx->max_buf = 0; + ub_ctx->flags = 0; + + ub_ctx->fd = open(CONTROL_FILE, O_RDWR); + if (ub_ctx->fd < 0) { + result = -ENOENT; + goto error; + } + + result = ublock_do_request(ub_ctx, in_buf, size, out_buf, size); + if (result) { + result = -EPROTO; + goto error; + } + if (!ub_ctx->flags & CTX_INITED) { + result = -EPROTO; + goto error; + } + + free(in_buf); + in_buf = NULL; + free(out_buf); + out_buf = NULL; + + ub_ctx->in_buf = malloc(ub_ctx->max_buf); + ub_ctx->out_buf = malloc(ub_ctx->max_buf); + if (!(ub_ctx->in_buf && ub_ctx->out_buf)) { + result = -ENOMEM; + goto error; + } + + ublock_loop(ub_ctx, EXIT_READY); + + *ub_ctx_out = ub_ctx; + + return 0; + +error: + if (ub_ctx) { + if (ub_ctx->in_buf) + free(ub_ctx->in_buf); + if (ub_ctx->out_buf) + free(ub_ctx->out_buf); + if (ub_ctx->fd) + close(ub_ctx->fd); + free(ub_ctx); + } + if (in_buf) + free(in_buf); + if (out_buf) + free(out_buf); + + return result; +} + +void ublock_destroy(struct ublock_ctx *ub_ctx) +{ + if (!ub_ctx) + return; + + close(ub_ctx->fd); + free(ub_ctx); +} |