diff options
Diffstat (limited to 'lib9p/core.c')
| -rw-r--r-- | lib9p/core.c | 202 |
1 files changed, 193 insertions, 9 deletions
diff --git a/lib9p/core.c b/lib9p/core.c index cb8ddee..03cdea5 100644 --- a/lib9p/core.c +++ b/lib9p/core.c @@ -4,14 +4,18 @@ * SPDX-License-Identifier: AGPL-3.0-or-later */ -#include <inttypes.h> /* for PRIu{n} */ -#include <stdarg.h> /* for va_* */ -#include <string.h> /* for strncpy() */ +#include <stdarg.h> /* for va_* */ +#include <string.h> /* for strlen(), strnlen(), strncpy(), memcmp(), memset() */ -#include <libfmt/fmt.h> /* for fmt_vsnprintf() */ +#include <libfmt/fmt.h> /* for fmt_vsnprintf() */ +#include <libmisc/assert.h> /* for assert() */ +#include <libmisc/endian.h> /* for uint32le_decode() */ +#include <libmisc/log.h> /* for const_byte_str() */ #include <lib9p/core.h> +#include "core_tables.h" + /* strings ********************************************************************/ struct lib9p_s lib9p_str(char *s) { @@ -58,10 +62,7 @@ bool lib9p_ctx_has_error(struct lib9p_ctx *ctx) { return ctx->err_msg[0]; } -#undef lib9p_error -#undef lib9p_errorf - -int lib9p_error(struct lib9p_ctx *ctx, +int _lib9p_error(struct lib9p_ctx *ctx, #if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L lib9p_errno_t linux_errno, #endif @@ -78,7 +79,7 @@ int lib9p_error(struct lib9p_ctx *ctx, return -1; } -int lib9p_errorf(struct lib9p_ctx *ctx, +int _lib9p_errorf(struct lib9p_ctx *ctx, #if CONFIG_9P_ENABLE_9P2000_u || CONFIG_9P_ENABLE_9P2000_L lib9p_errno_t linux_errno, #endif @@ -100,3 +101,186 @@ int lib9p_errorf(struct lib9p_ctx *ctx, return -1; } + +/* bounds checks **************************************************************/ + +static inline void assert_ver(enum lib9p_version ver) { +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wtype-limits" + assert(0 <= ver && ver < LIB9P_VER_NUM); +#pragma GCC diagnostic pop +} + +static inline void assert_typ(enum lib9p_msg_type typ) { +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wtype-limits" + assert(0 <= typ && typ < 0xFF); +#pragma GCC diagnostic pop +} + +/* simple lookups *************************************************************/ + +const char *lib9p_version_str(enum lib9p_version ver) { + assert_ver(ver); + return _lib9p_table_ver[ver].name; +} + +uint32_t lib9p_version_min_Rerror_size(enum lib9p_version ver) { + assert_ver(ver); + return _lib9p_table_ver[ver].min_Rerror_size; +} + +uint32_t lib9p_version_min_Rread_size(enum lib9p_version ver) { + assert_ver(ver); + return _lib9p_table_ver[ver].min_Rread_size; +} + +const char *lib9p_msgtype_str(enum lib9p_version ver, enum lib9p_msg_type typ) { + assert_ver(ver); + assert_typ(typ); + return _lib9p_table_msg[ver][typ].name ?: const_byte_str(typ); +} + +lo_interface fmt_formatter lo_box_lib9p_msg_as_fmt_formatter(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body) { + assert(ctx); + assert_ver(ctx->version); + assert_typ(typ); + assert(_lib9p_table_msg[ctx->version][typ].box_as_fmt_formatter); + return _lib9p_table_msg[ctx->version][typ].box_as_fmt_formatter(body); +} + +/* main message functions *****************************************************/ + +static +ssize_t _lib9p_validate(uint8_t xxx_low_typ_bit, + const char *xxx_errmsg, + const struct _lib9p_recv_tentry xxx_table[LIB9P_VER_NUM][0x80], + struct lib9p_ctx *ctx, uint8_t *net_bytes) { + assert_ver(ctx->version); + /* Inspect the first 5 bytes ourselves. */ + uint32_t net_size = uint32le_decode(net_bytes); + if (net_size < 5) + return lib9p_error(ctx, LIB9P_ERRNO_L_EBADMSG, "message is impossibly short"); + uint8_t typ = net_bytes[4]; + if (typ % 2 != xxx_low_typ_bit) + return lib9p_errorf(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, "%s: message_type=%s", xxx_errmsg, + lib9p_msgtype_str(ctx->version, typ)); + struct _lib9p_recv_tentry tentry = xxx_table[ctx->version][typ/2]; + if (!tentry.validate) + return lib9p_errorf(ctx, LIB9P_ERRNO_L_EOPNOTSUPP, "unknown message type: %s (protocol_version=%s)", + lib9p_msgtype_str(ctx->version, typ), lib9p_version_str(ctx->version)); + + /* Now use the message-type-specific tentry to process the whole thing. */ + return tentry.validate(ctx, net_size, net_bytes); +} + +ssize_t lib9p_Tmsg_validate(struct lib9p_ctx *ctx, uint8_t *net_bytes) { + return _lib9p_validate(0, "expected a T-message but got an R-message", _lib9p_table_Tmsg_recv, + ctx, net_bytes); +} + +ssize_t lib9p_Rmsg_validate(struct lib9p_ctx *ctx, uint8_t *net_bytes) { + return _lib9p_validate(1, "expected an R-message but got a T-message", _lib9p_table_Rmsg_recv, + ctx, net_bytes); +} + +static +void _lib9p_unmarshal(const struct _lib9p_recv_tentry xxx_table[LIB9P_VER_NUM][0x80], + struct lib9p_ctx *ctx, uint8_t *net_bytes, + enum lib9p_msg_type *ret_typ, void *ret_body) { + assert_ver(ctx->version); + enum lib9p_msg_type typ = net_bytes[4]; + *ret_typ = typ; + struct _lib9p_recv_tentry tentry = xxx_table[ctx->version][typ/2]; + assert(tentry.unmarshal); + + tentry.unmarshal(ctx, net_bytes, ret_body); +} + +void lib9p_Tmsg_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes, + enum lib9p_msg_type *ret_typ, void *ret_body) { + _lib9p_unmarshal(_lib9p_table_Tmsg_recv, + ctx, net_bytes, ret_typ, ret_body); +} + +void lib9p_Rmsg_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes, + enum lib9p_msg_type *ret_typ, void *ret_body) { + _lib9p_unmarshal(_lib9p_table_Rmsg_recv, + ctx, net_bytes, ret_typ, ret_body); +} + +static +bool _lib9p_marshal(const struct _lib9p_send_tentry xxx_table[LIB9P_VER_NUM][0x80], + struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body, + size_t *ret_iov_cnt, struct iovec *ret_iov, uint8_t *ret_copied) { + assert_ver(ctx->version); + assert_typ(typ); + struct _marshal_ret ret = { + .net_iov_cnt = 1, + .net_iov = ret_iov, + .net_copied_size = 0, + .net_copied = ret_copied, + }; + struct _lib9p_send_tentry tentry = xxx_table[ctx->version][typ/2]; + assert(tentry.marshal); + + bool ret_erred = tentry.marshal(ctx, body, &ret); + if (ret_iov[ret.net_iov_cnt-1].iov_len == 0) + ret.net_iov_cnt--; + *ret_iov_cnt = ret.net_iov_cnt; + return ret_erred; +} + +bool lib9p_Tmsg_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body, + struct lib9p_Tmsg_send_buf *ret) { + assert(typ % 2 == 0); + memset(ret, 0, sizeof(*ret)); + return _lib9p_marshal(_lib9p_table_Tmsg_send, + ctx, typ, body, + &ret->iov_cnt, ret->iov, ret->copied); +} + +bool lib9p_Rmsg_marshal(struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void *body, + struct lib9p_Rmsg_send_buf *ret) { + assert(typ % 2 == 1); + memset(ret, 0, sizeof(*ret)); + return _lib9p_marshal(_lib9p_table_Rmsg_send, + ctx, typ, body, + &ret->iov_cnt, ret->iov, ret->copied); +} + +/* `struct lib9p_stat` helpers ************************************************/ + +#if _LIB9P_ENABLE_stat +bool lib9p_stat_validate(struct lib9p_ctx *ctx, uint32_t net_size, uint8_t *net_bytes, + uint32_t *ret_net_size, size_t *ret_host_size) { + ssize_t host_size = _lib9p_stat_validate(ctx, net_size, net_bytes, ret_net_size); + if (host_size < 0) + return true; + if (ret_host_size) + *ret_host_size = (size_t)host_size; + return false; +} + +void lib9p_stat_unmarshal(struct lib9p_ctx *ctx, uint8_t *net_bytes, + struct lib9p_stat *ret) { + _lib9p_stat_unmarshal(ctx, net_bytes, ret); +} + +uint32_t lib9p_stat_marshal(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 iovec iov = {0}; + struct _marshal_ret ret = { + .net_iov_cnt = 1, + .net_iov = &iov, + .net_copied_size = 0, + .net_copied = ret_bytes, + }; + if (_lib9p_stat_marshal(&_ctx, obj, &ret)) + return 0; + return ret.net_iov[0].iov_len; +} +#endif |