[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] tools/xen-9pfsd: add 9pfs version request support
commit bcec59cf7ff4c3dfa1a417332b59e7e87c0f1f71 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Thu Feb 15 14:04:53 2024 +0100 Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> CommitDate: Thu Feb 15 16:24:39 2024 +0000 tools/xen-9pfsd: add 9pfs version request support Add the version request of the 9pfs protocol. For the version use the "9P2000.u" variant, as it is supported by Mini-OS and Linux. For the request parsing add all format items needed even in future in order to avoid code churn for those additions later. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Acked-by: Anthony PERARD <anthony.perard@xxxxxxxxxx> Reviewed-by: Jason Andryuk <jandryuk@xxxxxxxxx> --- tools/9pfsd/io.c | 201 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 201 insertions(+) diff --git a/tools/9pfsd/io.c b/tools/9pfsd/io.c index 12539677df..27571da192 100644 --- a/tools/9pfsd/io.c +++ b/tools/9pfsd/io.c @@ -22,8 +22,12 @@ #include "xen-9pfsd.h" /* P9 protocol commands (response is either cmd+1 or P9_CMD_ERROR). */ +#define P9_CMD_VERSION 100 #define P9_CMD_ERROR 107 +#define P9_MIN_MSIZE 2048 +#define P9_VERSION "9P2000.u" + struct p9_qid { uint8_t type; #define QID_TYPE_DIR 0x80 @@ -294,6 +298,169 @@ static unsigned int add_string(struct ring *ring, const char *str, return ret; } +static bool chk_data(struct ring *ring, void *data, unsigned int len) +{ + struct p9_header *hdr = ring->buffer; + + if ( data + len <= ring->buffer + hdr->size ) + return true; + + errno = E2BIG; + + return false; +} + +static bool fill_data_elem(void **par, void **array, unsigned int *array_sz, + unsigned int elem_sz, void *data) +{ + if ( *array_sz && !*array ) + { + *array = calloc(*array_sz, elem_sz); + if ( !*array ) + return false; + *par = *array; + } + + memcpy(*par, data, elem_sz); + + if ( *array_sz ) + { + *par += elem_sz; + *array_sz -= 1; + } + + return true; +} + +/* + * Fill variables with request data. + * fmt is a sequence of format characters. Supported characters are: + * a: an array (2 bytes number of elements + the following format as elements) + * The number of elements is stored in the first unsigned int parameter, the + * next parameter is a pointer to an array of elements as denoted by the next + * format character. The array is allocated dynamically. + * b: 1 byte unsigned integer + * The value is stored in the next parameter with type uint8_t. + * D: Data blob (4 byte length + <length> bytes) + * 2 parameters are consumed, first an unsigned int for the length, then a + * pointer to the first uint8_t value. + * No array support. + * L: 8 byte unsigned integer + * The value is stored in the next parameter with type uint64_t. + * S: String (2 byte length + <length> characters) + * The 0-terminated string is stored in device->str + off, off is stored in + * the next parameter with type unsigned int. + * U: 4 byte unsigned integer + * The value is stored in the next parameter with type uint32_t. + * + * Return value: number of filled variables, errno will be set in case of + * error. + */ +static int fill_data(struct ring *ring, const char *fmt, ...) +{ + struct p9_header *hdr = ring->buffer; + void *data = hdr + 1; + void *par; + unsigned int pars = 0; + const char *f; + va_list ap; + unsigned int len; + unsigned int str_off; + unsigned int array_sz = 0; + void **array = NULL; + + va_start(ap, fmt); + + for ( f = fmt; *f; f++ ) + { + if ( !array_sz ) + par = va_arg(ap, void *); + + switch ( *f ) + { + case 'a': + f++; + if ( !*f || array_sz ) + fmt_err(fmt); + if ( !chk_data(ring, data, sizeof(uint16_t)) ) + return pars; + array_sz = get_unaligned((uint16_t *)data); + data += sizeof(uint16_t); + *(unsigned int *)par = array_sz; + array = va_arg(ap, void **); + *array = NULL; + break; + + case 'b': + if ( !chk_data(ring, data, sizeof(uint8_t)) ) + return pars; + if ( !fill_data_elem(&par, array, &array_sz, sizeof(uint8_t), + data) ) + return pars; + data += sizeof(uint8_t); + break; + + case 'D': + if ( array_sz ) + fmt_err(fmt); + if ( !chk_data(ring, data, sizeof(uint32_t)) ) + return pars; + len = get_unaligned((uint32_t *)data); + data += sizeof(uint32_t); + *(unsigned int *)par = len; + par = va_arg(ap, void *); + if ( !chk_data(ring, data, len) ) + return pars; + memcpy(par, data, len); + data += len; + break; + + case 'L': + if ( !chk_data(ring, data, sizeof(uint64_t)) ) + return pars; + if ( !fill_data_elem(&par, array, &array_sz, sizeof(uint64_t), + data) ) + return pars; + data += sizeof(uint64_t); + break; + + case 'S': + if ( !chk_data(ring, data, sizeof(uint16_t)) ) + return pars; + len = get_unaligned((uint16_t *)data); + data += sizeof(uint16_t); + if ( !chk_data(ring, data, len) ) + return pars; + str_off = add_string(ring, data, len); + if ( str_off == ~0 ) + return pars; + if ( !fill_data_elem(&par, array, &array_sz, sizeof(unsigned int), + &str_off) ) + return pars; + data += len; + break; + + case 'U': + if ( !chk_data(ring, data, sizeof(uint32_t)) ) + return pars; + if ( !fill_data_elem(&par, array, &array_sz, sizeof(uint32_t), + data) ) + return pars; + data += sizeof(uint32_t); + break; + + default: + fmt_err(fmt); + } + + if ( array_sz ) + f--; + pars++; + } + + return pars; +} + static void p9_error(struct ring *ring, uint16_t tag, uint32_t err) { unsigned int erroff; @@ -305,6 +472,36 @@ static void p9_error(struct ring *ring, uint16_t tag, uint32_t err) &err); } +static void p9_version(struct ring *ring, struct p9_header *hdr) +{ + uint32_t max_size; + unsigned int off; + char *version; + int ret; + + ret = fill_data(ring, "US", &max_size, &off); + if ( ret != 2 ) + { + p9_error(ring, hdr->tag, errno); + return; + } + + if ( max_size < P9_MIN_MSIZE ) + { + p9_error(ring, hdr->tag, EMSGSIZE); + return; + } + + if ( max_size < ring->max_size ) + ring->max_size = max_size; + + version = ring->str + off; + if ( strcmp(version, P9_VERSION) ) + version = "unknown"; + + fill_buffer(ring, hdr->cmd + 1, hdr->tag, "US", &ring->max_size, version); +} + void *io_thread(void *arg) { struct ring *ring = arg; @@ -360,6 +557,10 @@ void *io_thread(void *arg) switch ( hdr.cmd ) { + case P9_CMD_VERSION: + p9_version(ring, &hdr); + break; + default: syslog(LOG_DEBUG, "%u.%u sent unhandled command %u\n", ring->device->domid, ring->device->devid, hdr.cmd); -- generated by git-patchbot for /home/xen/git/xen.git#staging
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