Re: [PATCH] support colon in filenames

[Ram Pai <linuxram@us.ibm.com>]

Copying the qemu-devel mailing list too.

On Wed, 2009-06-24 at 09:58 -0700, Ram Pai wrote:
> Problem: It is impossible to feed filenames with the character colon because 
> qemu interprets such names as a protocol. For example  a filename scsi:0,
> is interpreted as a protocol by name "scsi".
> 
> This patch allows users to espace colon characters. For example the above filename
> can now be expressed as 'scsi\:0'
> 
> Here are couple of examples:
> 
> ndb:\::9999  is treated as a ndb protocol with a hostname ':' on port 9999
> scsi\:0\:abc is a local file scsi:0:abc
> http\://myweb is a local file by name http://myweb
> nbd\::localhost:2558  is a protocol by name nbd: 
> 
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> -----------------------------------------------------------------------
> 
> 
>  block.c           |   26 +++++++++++++++++---------
>  block/nbd.c       |   19 ++++++++++++++-----
>  block/raw-posix.c |   24 +++++++++++++++++-------
>  cutils.c          |   22 ++++++++++++++++++++++
>  qemu-common.h     |    1 +
>  vl.c              |    3 +--
>  6 files changed, 72 insertions(+), 23 deletions(-)
> 
> diff --git a/block.c b/block.c
> index aca5a6d..80bded9 100644
> --- a/block.c
> +++ b/block.c
> @@ -225,22 +225,30 @@ static BlockDriver *find_protocol(const char *filename)
>  {
>      BlockDriver *drv1;
>      char protocol[128];
> -    int len;
> -    const char *p;
> +    char *p = protocol; 
> +    const char *f=filename;
> +    int len = strnlen(filename, 128);
> 
>  #ifdef _WIN32
>      if (is_windows_drive(filename) ||
>          is_windows_drive_prefix(filename))
>          return bdrv_find_format("raw");
>  #endif
> -    p = strchr(filename, ':');
> -    if (!p)
> +    while ( f < filename+len ) {
> +	if ( *f == ':' )
> +		break;
> +	if ( *f == '\\') {
> +		f++;
> +		if ( *f == '\0')
> +			break;
> +	}
> +	*p++ = *f++;
> +    }
> +    *p='\0';
> +
> +    if (*f != ':')
>          return bdrv_find_format("raw");
> -    len = p - filename;
> -    if (len > sizeof(protocol) - 1)
> -        len = sizeof(protocol) - 1;
> -    memcpy(protocol, filename, len);
> -    protocol[len] = '\0';
> +
>      for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
>          if (drv1->protocol_name &&
>              !strcmp(drv1->protocol_name, protocol))
> diff --git a/block/nbd.c b/block/nbd.c
> index 47d4778..a011cc7 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -64,18 +64,27 @@ static int nbd_open(BlockDriverState *bs, const char* filename, int flags)
> 
>      } else {
>          uint16_t port;
> -        char *p, *r;
> +        char *q, *p, *r;
>          char hostname[128];
> 
>          pstrcpy(hostname, 128, host);
> 
> -        p = strchr(hostname, ':');
> -        if (p == NULL)
> +	q=p=hostname;
> +	while ( p < hostname+128 ) {
> +		if (*p == ':')
> +			break;
> +		if ( *p == '\\' )  {
> +			p++;
> +			if (*p =='\0') 
> +				break;
> +		}
> +		*q++=*p++;
> +	}
> +        if (*p != ':')
>              return -EINVAL;
> 
> -        *p = '\0';
> +	*q='\0';
>          p++;
> -
>          port = strtol(p, &r, 0);
>          if (r == p)
>              return -EINVAL;
> diff --git a/block/raw-posix.c b/block/raw-posix.c
> index 41bfa37..98ede17 100644
> --- a/block/raw-posix.c
> +++ b/block/raw-posix.c
> @@ -124,6 +124,16 @@ static int fd_open(BlockDriverState *bs);
>  static int cdrom_reopen(BlockDriverState *bs);
>  #endif
> 
> +static int _open(const char *filename, int flags, ...)
> +{
> +	char myfile[PATH_MAX];
> +   	va_list ap;
> +   	va_start(ap, flags);
> +	return  open(esc_string(myfile, PATH_MAX, filename),
> +				flags, ap);
> +}
> +
> +
>  static int raw_open_common(BlockDriverState *bs, const char *filename,
>          int flags)
>  {
> @@ -151,7 +161,7 @@ static int raw_open_common(BlockDriverState *bs, const char *filename,
>          s->open_flags |= O_DSYNC;
> 
>      s->fd = -1;
> -    fd = open(filename, s->open_flags, 0644);
> +    fd = _open(filename, s->open_flags, 0644);
>      if (fd < 0) {
>          ret = -errno;
>          if (ret == -EROFS)
> @@ -844,7 +854,7 @@ static int raw_create(const char *filename, QEMUOptionParameter *options)
>          options++;
>      }
> 
> -    fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
> +    fd = _open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY,
>                0644);
>      if (fd < 0)
>          return -EIO;
> @@ -985,7 +995,7 @@ static int hdev_open(BlockDriverState *bs, const char *filename, int flags)
>          if ( bsdPath[ 0 ] != '\0' ) {
>              strcat(bsdPath,"s0");
>              /* some CDs don't have a partition 0 */
> -            fd = open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
> +            fd = _open(bsdPath, O_RDONLY | O_BINARY | O_LARGEFILE);
>              if (fd < 0) {
>                  bsdPath[strlen(bsdPath)-1] = '1';
>              } else {
> @@ -1037,7 +1047,7 @@ static int fd_open(BlockDriverState *bs)
>  #endif
>              return -EIO;
>          }
> -        s->fd = open(bs->filename, s->open_flags & ~O_NONBLOCK);
> +        s->fd = _open(bs->filename, s->open_flags & ~O_NONBLOCK);
>          if (s->fd < 0) {
>              s->fd_error_time = qemu_get_clock(rt_clock);
>              s->fd_got_error = 1;
> @@ -1133,7 +1143,7 @@ static int hdev_create(const char *filename, QEMUOptionParameter *options)
>          options++;
>      }
> 
> -    fd = open(filename, O_WRONLY | O_BINARY);
> +    fd = _open(filename, O_WRONLY | O_BINARY);
>      if (fd < 0)
>          return -EIO;
> 
> @@ -1239,7 +1249,7 @@ static int floppy_eject(BlockDriverState *bs, int eject_flag)
>          close(s->fd);
>          s->fd = -1;
>      }
> -    fd = open(bs->filename, s->open_flags | O_NONBLOCK);
> +    fd = _open(bs->filename, s->open_flags | O_NONBLOCK);
>      if (fd >= 0) {
>          if (ioctl(fd, FDEJECT, 0) < 0)
>              perror("FDEJECT");
> @@ -1399,7 +1409,7 @@ static int cdrom_reopen(BlockDriverState *bs)
>       */
>      if (s->fd >= 0)
>          close(s->fd);
> -    fd = open(bs->filename, s->open_flags, 0644);
> +    fd = _open(bs->filename, s->open_flags, 0644);
>      if (fd < 0) {
>          s->fd = -1;
>          return -EIO;
> diff --git a/cutils.c b/cutils.c
> index 6ea0c49..63c196d 100644
> --- a/cutils.c
> +++ b/cutils.c
> @@ -24,6 +24,28 @@
>  #include "qemu-common.h"
>  #include "host-utils.h"
> 
> +/*
> + * prune escape character '\'
> + */
> +char *esc_string(char *buf, int buf_size, const char *str)
> +{
> +        const char *p=str;
> +        int len = strlen(str);
> +        char *q=buf;
> +
> +	len = (buf_size < len) ? buf_size: len;
> +        while (p < str+len) {
> +                if (*p == '\\') {
> +                        p++;
> +			if (*p == '\0')
> +				break;
> +		}
> +                *q++ = *p++;
> +        }
> +        *q='\0';
> +	return buf;
> +}
> +
>  void pstrcpy(char *buf, int buf_size, const char *str)
>  {
>      int c;
> diff --git a/qemu-common.h b/qemu-common.h
> index 2dcb224..1e510dc 100644
> --- a/qemu-common.h
> +++ b/qemu-common.h
> @@ -104,6 +104,7 @@ void qemu_get_timedate(struct tm *tm, int offset);
>  int qemu_timedate_diff(struct tm *tm);
> 
>  /* cutils.c */
> +char *esc_string(char *buf, int buf_size, const char *str);
>  void pstrcpy(char *buf, int buf_size, const char *str);
>  char *pstrcat(char *buf, int buf_size, const char *s);
>  int strstart(const char *str, const char *val, const char **ptr);
> diff --git a/vl.c b/vl.c
> index 7278999..5d7b024 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -2583,8 +2583,7 @@ int drive_init(struct drive_opt *arg, int snapshot, void *opaque)
>      else if (cache == 3) /* not specified */
>          bdrv_flags |= BDRV_O_CACHE_DEF;
>      if (bdrv_open2(bdrv, file, bdrv_flags, drv) < 0) {
> -        fprintf(stderr, "qemu: could not open disk image %s\n",
> -                        file);
> +        fprintf(stderr, "qemu: could not open disk image %s\n", file);
>          return -1;
>      }
>      if (bdrv_key_required(bdrv))
> 
> 
> 
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