diff options
Diffstat (limited to 'drivers/staging/unisys/visorchipset/parser.c')
| -rw-r--r-- | drivers/staging/unisys/visorchipset/parser.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/staging/unisys/visorchipset/parser.c b/drivers/staging/unisys/visorchipset/parser.c new file mode 100644 index 000000000000..b408d415bd8c --- /dev/null +++ b/drivers/staging/unisys/visorchipset/parser.c @@ -0,0 +1,474 @@ +/* parser.c + * + * Copyright © 2010 - 2013 UNISYS CORPORATION + * All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for more + * details. + */ + +#include "parser.h" +#include "memregion.h" +#include "controlvmchannel.h" +#include <linux/ctype.h> +#include <linux/mm.h> + +#define MYDRVNAME "visorchipset_parser" +#define CURRENT_FILE_PC VISOR_CHIPSET_PC_parser_c + +/* We will refuse to allocate more than this many bytes to copy data from + * incoming payloads. This serves as a throttling mechanism. + */ +#define MAX_CONTROLVM_PAYLOAD_BYTES (1024*128) +static ulong Controlvm_Payload_Bytes_Buffered; + +struct PARSER_CONTEXT_Tag { + ulong allocbytes; + ulong param_bytes; + u8 *curr; + ulong bytes_remaining; + BOOL byte_stream; + char data[0]; +}; + +static PARSER_CONTEXT * +parser_init_guts(U64 addr, U32 bytes, BOOL isLocal, + BOOL hasStandardPayloadHeader, BOOL *tryAgain) +{ + int allocbytes = sizeof(PARSER_CONTEXT) + bytes; + PARSER_CONTEXT *rc = NULL; + PARSER_CONTEXT *ctx = NULL; + MEMREGION *rgn = NULL; + ULTRA_CONTROLVM_PARAMETERS_HEADER *phdr = NULL; + + if (tryAgain) + *tryAgain = FALSE; + if (!hasStandardPayloadHeader) + /* alloc and 0 extra byte to ensure payload is + * '\0'-terminated + */ + allocbytes++; + if ((Controlvm_Payload_Bytes_Buffered + bytes) + > MAX_CONTROLVM_PAYLOAD_BYTES) { + ERRDRV("%s (%s:%d) - prevented allocation of %d bytes to prevent exceeding throttling max (%d)", + __func__, __FILE__, __LINE__, allocbytes, + MAX_CONTROLVM_PAYLOAD_BYTES); + if (tryAgain) + *tryAgain = TRUE; + rc = NULL; + goto Away; + } + ctx = kzalloc(allocbytes, GFP_KERNEL|__GFP_NORETRY); + if (ctx == NULL) { + ERRDRV("%s (%s:%d) - failed to allocate %d bytes", + __func__, __FILE__, __LINE__, allocbytes); + if (tryAgain) + *tryAgain = TRUE; + rc = NULL; + goto Away; + } + + ctx->allocbytes = allocbytes; + ctx->param_bytes = bytes; + ctx->curr = NULL; + ctx->bytes_remaining = 0; + ctx->byte_stream = FALSE; + if (isLocal) { + void *p; + if (addr > virt_to_phys(high_memory - 1)) { + ERRDRV("%s - bad local address (0x%-16.16Lx for %lu)", + __func__, + (unsigned long long) addr, (ulong) bytes); + rc = NULL; + goto Away; + } + p = __va((ulong) (addr)); + memcpy(ctx->data, p, bytes); + } else { + rgn = visor_memregion_create(addr, bytes); + if (!rgn) { + rc = NULL; + goto Away; + } + if (visor_memregion_read(rgn, 0, ctx->data, bytes) < 0) { + rc = NULL; + goto Away; + } + } + if (!hasStandardPayloadHeader) { + ctx->byte_stream = TRUE; + rc = ctx; + goto Away; + } + phdr = (ULTRA_CONTROLVM_PARAMETERS_HEADER *) (ctx->data); + if (phdr->TotalLength != bytes) { + ERRDRV("%s - bad total length %lu (should be %lu)", + __func__, + (ulong) (phdr->TotalLength), (ulong) (bytes)); + rc = NULL; + goto Away; + } + if (phdr->TotalLength < phdr->HeaderLength) { + ERRDRV("%s - total length < header length (%lu < %lu)", + __func__, + (ulong) (phdr->TotalLength), + (ulong) (phdr->HeaderLength)); + rc = NULL; + goto Away; + } + if (phdr->HeaderLength < sizeof(ULTRA_CONTROLVM_PARAMETERS_HEADER)) { + ERRDRV("%s - header is too small (%lu < %lu)", + __func__, + (ulong) (phdr->HeaderLength), + (ulong) (sizeof(ULTRA_CONTROLVM_PARAMETERS_HEADER))); + rc = NULL; + goto Away; + } + + rc = ctx; +Away: + if (rgn) { + visor_memregion_destroy(rgn); + rgn = NULL; + } + if (rc) + Controlvm_Payload_Bytes_Buffered += ctx->param_bytes; + else { + if (ctx) { + parser_done(ctx); + ctx = NULL; + } + } + return rc; +} + +PARSER_CONTEXT * +parser_init(U64 addr, U32 bytes, BOOL isLocal, BOOL *tryAgain) +{ + return parser_init_guts(addr, bytes, isLocal, TRUE, tryAgain); +} + +/* Call this instead of parser_init() if the payload area consists of just + * a sequence of bytes, rather than a ULTRA_CONTROLVM_PARAMETERS_HEADER + * structures. Afterwards, you can call parser_simpleString_get() or + * parser_byteStream_get() to obtain the data. + */ +PARSER_CONTEXT * +parser_init_byteStream(U64 addr, U32 bytes, BOOL isLocal, BOOL *tryAgain) +{ + return parser_init_guts(addr, bytes, isLocal, FALSE, tryAgain); +} + +/* Obtain '\0'-terminated copy of string in payload area. + */ +char * +parser_simpleString_get(PARSER_CONTEXT *ctx) +{ + if (!ctx->byte_stream) + return NULL; + return ctx->data; /* note this IS '\0'-terminated, because of + * the num of bytes we alloc+clear in + * parser_init_byteStream() */ +} + +/* Obtain a copy of the buffer in the payload area. + */ +void * +parser_byteStream_get(PARSER_CONTEXT *ctx, ulong *nbytes) +{ + if (!ctx->byte_stream) + return NULL; + if (nbytes) + *nbytes = ctx->param_bytes; + return (void *) ctx->data; +} + +GUID +parser_id_get(PARSER_CONTEXT *ctx) +{ + ULTRA_CONTROLVM_PARAMETERS_HEADER *phdr = NULL; + + if (ctx == NULL) { + ERRDRV("%s (%s:%d) - no context", + __func__, __FILE__, __LINE__); + return Guid0; + } + phdr = (ULTRA_CONTROLVM_PARAMETERS_HEADER *) (ctx->data); + return phdr->Id; +} + +void +parser_param_start(PARSER_CONTEXT *ctx, PARSER_WHICH_STRING which_string) +{ + ULTRA_CONTROLVM_PARAMETERS_HEADER *phdr = NULL; + + if (ctx == NULL) { + ERRDRV("%s (%s:%d) - no context", + __func__, __FILE__, __LINE__); + goto Away; + } + phdr = (ULTRA_CONTROLVM_PARAMETERS_HEADER *) (ctx->data); + switch (which_string) { + case PARSERSTRING_INITIATOR: + ctx->curr = ctx->data + phdr->InitiatorOffset; + ctx->bytes_remaining = phdr->InitiatorLength; + break; + case PARSERSTRING_TARGET: + ctx->curr = ctx->data + phdr->TargetOffset; + ctx->bytes_remaining = phdr->TargetLength; + break; + case PARSERSTRING_CONNECTION: + ctx->curr = ctx->data + phdr->ConnectionOffset; + ctx->bytes_remaining = phdr->ConnectionLength; + break; + case PARSERSTRING_NAME: + ctx->curr = ctx->data + phdr->NameOffset; + ctx->bytes_remaining = phdr->NameLength; + break; + default: + ERRDRV("%s - bad which_string %d", __func__, which_string); + break; + } + +Away: + return; +} + +void +parser_done(PARSER_CONTEXT *ctx) +{ + if (!ctx) + return; + Controlvm_Payload_Bytes_Buffered -= ctx->param_bytes; + kfree(ctx); +} + +/** Return length of string not counting trailing spaces. */ +static int +string_length_no_trail(char *s, int len) +{ + int i = len - 1; + while (i >= 0) { + if (!isspace(s[i])) + return i + 1; + i--; + } + return 0; +} + +/** Grab the next name and value out of the parameter buffer. + * The entire parameter buffer looks like this: + * <name>=<value>\0 + * <name>=<value>\0 + * ... + * \0 + * If successful, the next <name> value is returned within the supplied + * <nam> buffer (the value is always upper-cased), and the corresponding + * <value> is returned within a kmalloc()ed buffer, whose pointer is + * provided as the return value of this function. + * (The total number of bytes allocated is strlen(<value>)+1.) + * + * NULL is returned to indicate failure, which can occur for several reasons: + * - all <name>=<value> pairs have already been processed + * - bad parameter + * - parameter buffer ends prematurely (couldn't find an '=' or '\0' within + * the confines of the parameter buffer) + * - the <nam> buffer is not large enough to hold the <name> of the next + * parameter + */ +void * +parser_param_get(PARSER_CONTEXT *ctx, char *nam, int namesize) +{ + u8 *pscan, *pnam = nam; + ulong nscan; + int value_length = -1, orig_value_length = -1; + void *value = NULL; + int i; + int closing_quote = 0; + + if (!ctx) + return NULL; + pscan = ctx->curr; + nscan = ctx->bytes_remaining; + if (nscan == 0) + return NULL; + if (*pscan == '\0') + /* This is the normal return point after you have processed + * all of the <name>=<value> pairs in a syntactically-valid + * parameter buffer. + */ + return NULL; + + /* skip whitespace */ + while (isspace(*pscan)) { + pscan++; + nscan--; + if (nscan == 0) + return NULL; + } + + while (*pscan != ':') { + if (namesize <= 0) { + ERRDRV("%s - name too big", __func__); + return NULL; + } + *pnam = toupper(*pscan); + pnam++; + namesize--; + pscan++; + nscan--; + if (nscan == 0) { + ERRDRV("%s - unexpected end of input parsing name", + __func__); + return NULL; + } + } + if (namesize <= 0) { + ERRDRV("%s - name too big", __func__); + return NULL; + } + *pnam = '\0'; + nam[string_length_no_trail(nam, strlen(nam))] = '\0'; + + /* point to char immediately after ":" in "<name>:<value>" */ + pscan++; + nscan--; + /* skip whitespace */ + while (isspace(*pscan)) { + pscan++; + nscan--; + if (nscan == 0) { + ERRDRV("%s - unexpected end of input looking for value", + __func__); + return NULL; + } + } + if (nscan == 0) { + ERRDRV("%s - unexpected end of input looking for value", + __func__); + return NULL; + } + if (*pscan == '\'' || *pscan == '"') { + closing_quote = *pscan; + pscan++; + nscan--; + if (nscan == 0) { + ERRDRV("%s - unexpected end of input after %c", + __func__, closing_quote); + return NULL; + } + } + + /* look for a separator character, terminator character, or + * end of data + */ + for (i = 0, value_length = -1; i < nscan; i++) { + if (closing_quote) { + if (pscan[i] == '\0') { + ERRDRV("%s - unexpected end of input parsing quoted value", __func__); + return NULL; + } + if (pscan[i] == closing_quote) { + value_length = i; + break; + } + } else + if (pscan[i] == ',' || pscan[i] == ';' + || pscan[i] == '\0') { + value_length = i; + break; + } + } + if (value_length < 0) { + if (closing_quote) { + ERRDRV("%s - unexpected end of input parsing quoted value", __func__); + return NULL; + } + value_length = nscan; + } + orig_value_length = value_length; + if (closing_quote == 0) + value_length = string_length_no_trail(pscan, orig_value_length); + value = kmalloc(value_length + 1, GFP_KERNEL|__GFP_NORETRY); + if (value == NULL) + return NULL; + memcpy(value, pscan, value_length); + ((u8 *) (value))[value_length] = '\0'; + + pscan += orig_value_length; + nscan -= orig_value_length; + + /* skip past separator or closing quote */ + if (nscan > 0) { + if (*pscan != '\0') { + pscan++; + nscan--; + } + } + + if (closing_quote && (nscan > 0)) { + /* we still need to skip around the real separator if present */ + /* first, skip whitespace */ + while (isspace(*pscan)) { + pscan++; + nscan--; + if (nscan == 0) + break; + } + if (nscan > 0) { + if (*pscan == ',' || *pscan == ';') { + pscan++; + nscan--; + } else if (*pscan != '\0') { + ERRDRV("%s - missing separator after quoted string", __func__); + kfree(value); + value = NULL; + return NULL; + } + } + } + ctx->curr = pscan; + ctx->bytes_remaining = nscan; + return value; +} + +void * +parser_string_get(PARSER_CONTEXT *ctx) +{ + u8 *pscan; + ulong nscan; + int value_length = -1; + void *value = NULL; + int i; + + if (!ctx) + return NULL; + pscan = ctx->curr; + nscan = ctx->bytes_remaining; + if (nscan == 0) + return NULL; + if (!pscan) + return NULL; + for (i = 0, value_length = -1; i < nscan; i++) + if (pscan[i] == '\0') { + value_length = i; + break; + } + if (value_length < 0) /* '\0' was not included in the length */ + value_length = nscan; + value = kmalloc(value_length + 1, GFP_KERNEL|__GFP_NORETRY); + if (value == NULL) + return NULL; + if (value_length > 0) + memcpy(value, pscan, value_length); + ((u8 *) (value))[value_length] = '\0'; + return value; +} |