diff options
Diffstat (limited to 'lib9p/9p.c')
| -rw-r--r-- | lib9p/9p.c | 181 |
1 files changed, 0 insertions, 181 deletions
diff --git a/lib9p/9p.c b/lib9p/9p.c deleted file mode 100644 index 5943b42..0000000 --- a/lib9p/9p.c +++ /dev/null @@ -1,181 +0,0 @@ -/* lib9p/9p.c - Base 9P protocol utilities for both clients and servers - * - * Copyright (C) 2024 Luke T. Shumaker <lukeshu@lukeshu.com> - * SPDX-License-Identifier: AGPL-3.0-or-later - */ - -#include <inttypes.h> /* for PRIu{n} */ -#include <stdarg.h> /* for va_* */ -#include <stdio.h> /* for vsnprintf() */ -#include <string.h> /* for strncpy() */ - -#include <lib9p/9p.h> - -#include "internal.h" - -/* ctx ************************************************************************/ - -void lib9p_ctx_clear_error(struct lib9p_ctx *ctx) { - assert(ctx); -#if CONFIG_9P_ENABLE_9P2000_u - ctx->err_num = 0; -#endif - ctx->err_msg[0] = '\0'; -} - -bool lib9p_ctx_has_error(struct lib9p_ctx *ctx) { - assert(ctx); - return ctx->err_msg[0]; -} - -int lib9p_error(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *msg) { - if (lib9p_ctx_has_error(ctx)) - return -1; - strncpy(ctx->err_msg, msg, sizeof(ctx->err_msg)); - ctx->err_msg[sizeof(ctx->err_msg)-1] = '\0'; - -#if CONFIG_9P_ENABLE_9P2000_u - ctx->err_num = linux_errno; -#else - (void)(linux_errno); -#endif - - return -1; -} - -int lib9p_errorf(struct lib9p_ctx *ctx, uint32_t linux_errno, char const *fmt, ...) { - int n; - va_list args; - - if (lib9p_ctx_has_error(ctx)) - return -1; - va_start(args, fmt); - n = vsnprintf(ctx->err_msg, sizeof(ctx->err_msg), fmt, args); - va_end(args); - if ((size_t)(n+1) < sizeof(ctx->err_msg)) - memset(&ctx->err_msg[n+1], 0, sizeof(ctx->err_msg)-(n+1)); - -#if CONFIG_9P_ENABLE_9P2000_u - ctx->err_num = linux_errno; -#else - (void)(linux_errno); -#endif - - return -1; -} - -const char *lib9p_msg_type_str(struct lib9p_ctx *ctx, enum lib9p_msg_type typ) { - assert(0 <= typ && typ <= 0xFF); - return _lib9p_versions[ctx->version].msgs[typ].name; -} - -/* main message functions *****************************************************/ - -ssize_t lib9p_validate(struct lib9p_ctx *ctx, uint8_t *net_bytes) { - /* Inspect the first 5 bytes ourselves. */ - struct _validate_ctx subctx = { - .ctx = ctx, - .net_size = decode_u32le(net_bytes), - .net_bytes = net_bytes, - - .net_offset = 0, - .host_extra = 0, - }; - if (subctx.net_size < 5) - return lib9p_error(ctx, LINUX_EBADMSG, "message is impossibly short"); - uint8_t typ = net_bytes[4]; - struct _table_msg table = _lib9p_versions[ctx->version].msgs[typ]; - if (!table.validate) - return lib9p_errorf(ctx, LINUX_EOPNOTSUPP, "unknown message type: %s (protocol_version=%s)", - lib9p_msg_type_str(ctx, typ), lib9p_version_str(ctx->version)); - - /* Now use the message-type-specific table to process the whole thing. */ - if (table.validate(&subctx)) - return -1; - assert(subctx.net_offset <= subctx.net_size); - if (subctx.net_offset < subctx.net_size) - return lib9p_errorf(ctx, LINUX_EBADMSG, "message has %"PRIu32" extra bytes", - subctx.net_size - subctx.net_offset); - - /* Return. */ - ssize_t ret; - if (__builtin_add_overflow(table.basesize, subctx.host_extra, &ret)) - return lib9p_error(ctx, LINUX_EMSGSIZE, "unmarshalled payload overflows SSIZE_MAX"); - return ret; -} - -void lib9p_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes, - enum lib9p_msg_type *ret_typ, void *ret_body) { - struct _unmarshal_ctx subctx = { - .ctx = ctx, - .net_bytes = net_bytes, - - .net_offset = 0, - }; - - *ret_typ = net_bytes[4]; - struct _table_msg table = _lib9p_versions[ctx->version].msgs[*ret_typ]; - subctx.extra = ret_body + table.basesize; - table.unmarshal(&subctx, ret_body); -} - -bool lib9p_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body, - uint8_t *ret_bytes) { - struct _marshal_ctx subctx = { - .ctx = ctx, - .net_bytes = ret_bytes, - .net_offset = 0, - }; - - struct _table_msg table = _lib9p_versions[ctx->version].msgs[typ]; - return table.marshal(&subctx, body); -} - -/* `struct lib9p_stat` helpers ************************************************/ - -bool lib9p_validate_stat(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *net_bytes, - uint32_t *ret_net_size, ssize_t *ret_host_size) { - struct _validate_ctx subctx = { - .ctx = ctx, - .net_size = net_size, - .net_bytes = net_bytes, - - .net_offset = 0, - .host_extra = 0, - }; - if (_lib9p_validate_stat(&subctx)) - return true; - if (ret_net_size) - *ret_net_size = subctx.net_offset; - if (ret_host_size) - if (__builtin_add_overflow(sizeof(struct lib9p_stat), subctx.host_extra, ret_host_size)) - return lib9p_error(ctx, LINUX_EMSGSIZE, "unmarshalled stat object overflows SSIZE_MAX"); - return false; -} - -uint32_t lib9p_unmarshal_stat(struct lib9p_ctx *ctx, uint8_t *net_bytes, - struct lib9p_stat *ret_obj, void *ret_extra) { - struct _unmarshal_ctx subctx = { - .ctx = ctx, - .net_bytes = net_bytes, - .net_offset = 0, - - .extra = ret_extra, - }; - _lib9p_unmarshal_stat(&subctx, ret_obj); - return subctx.net_offset; -} - -uint32_t lib9p_marshal_stat(struct lib9p_ctx *ctx, uint32_t max_net_size, struct lib9p_stat *obj, - uint8_t *ret_bytes) { - struct lib9p_ctx _ctx = *ctx; - _ctx.max_msg_size = max_net_size; - struct _marshal_ctx subctx = { - .ctx = &_ctx, - .net_bytes = ret_bytes, - .net_offset = 0, - }; - if (_lib9p_marshal_stat(&subctx, obj)) - return 0; - return subctx.net_offset; -} |