Patchwork [v9,2/4] sockets: change inet_connect() to support nonblock socket

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Submitter Amos Kong
Date April 25, 2012, 3:32 a.m.
Message ID <20120425033143.25606.92728.stgit@dhcp-8-167.nay.redhat.com>
Download mbox | patch
Permalink /patch/154784/
State New
Headers show

Comments

Amos Kong - April 25, 2012, 3:32 a.m.
Add a bool argument to inet_connect() to assign if set socket
to block/nonblock, and delete original argument 'socktype'
that is unused.
Add a new argument to inet_connect()/inet_connect_opts(),
to pass back connect error by error class.

Retry to connect when -EINTR is got. Connect's successful
for nonblock socket when following errors are got, user
should wait for connecting by select():
  -EINPROGRESS
  -EWOULDBLOCK (win32)
  -WSAEALREADY (win32)

Change nbd, vnc to use new interface.

Changes from v7:
- posix: let EWOULDBLOCK fall through to CONNECT_FAILED path
- fix typo

Changes from v8:
- reuse rc variable
- fix a NULL pointer dereference

Signed-off-by: Amos Kong <akong@redhat.com>
---
 nbd.c          |    2 +-
 qemu-char.c    |    2 +-
 qemu-sockets.c |   46 ++++++++++++++++++++++++++++++++++++++++------
 qemu_socket.h  |    6 ++++--
 ui/vnc.c       |    2 +-
 5 files changed, 47 insertions(+), 11 deletions(-)
Orit Wasserman - April 25, 2012, 5 a.m.
On 04/25/2012 06:32 AM, Amos Kong wrote:
> Add a bool argument to inet_connect() to assign if set socket
> to block/nonblock, and delete original argument 'socktype'
> that is unused.
> Add a new argument to inet_connect()/inet_connect_opts(),
> to pass back connect error by error class.
> 
> Retry to connect when -EINTR is got. Connect's successful
> for nonblock socket when following errors are got, user
> should wait for connecting by select():
>   -EINPROGRESS
>   -EWOULDBLOCK (win32)
>   -WSAEALREADY (win32)
> 
> Change nbd, vnc to use new interface.
> 
> Changes from v7:
> - posix: let EWOULDBLOCK fall through to CONNECT_FAILED path
> - fix typo
> 
> Changes from v8:
> - reuse rc variable
> - fix a NULL pointer dereference
> 
> Signed-off-by: Amos Kong <akong@redhat.com>
> ---
>  nbd.c          |    2 +-
>  qemu-char.c    |    2 +-
>  qemu-sockets.c |   46 ++++++++++++++++++++++++++++++++++++++++------
>  qemu_socket.h  |    6 ++++--
>  ui/vnc.c       |    2 +-
>  5 files changed, 47 insertions(+), 11 deletions(-)
> 
> diff --git a/nbd.c b/nbd.c
> index 406e555..bb71f00 100644
> --- a/nbd.c
> +++ b/nbd.c
> @@ -146,7 +146,7 @@ int tcp_socket_outgoing(const char *address, uint16_t port)
>  
>  int tcp_socket_outgoing_spec(const char *address_and_port)
>  {
> -    return inet_connect(address_and_port, SOCK_STREAM);
> +    return inet_connect(address_and_port, true, NULL);
>  }
>  
>  int tcp_socket_incoming(const char *address, uint16_t port)
> diff --git a/qemu-char.c b/qemu-char.c
> index 74c60e1..aeee2e8 100644
> --- a/qemu-char.c
> +++ b/qemu-char.c
> @@ -2444,7 +2444,7 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
>          if (is_listen) {
>              fd = inet_listen_opts(opts, 0);
>          } else {
> -            fd = inet_connect_opts(opts);
> +            fd = inet_connect_opts(opts, NULL);
>          }
>      }
>      if (fd < 0) {
> diff --git a/qemu-sockets.c b/qemu-sockets.c
> index 6bcb8e3..243af67 100644
> --- a/qemu-sockets.c
> +++ b/qemu-sockets.c
> @@ -51,6 +51,9 @@ static QemuOptsList dummy_opts = {
>          },{
>              .name = "ipv6",
>              .type = QEMU_OPT_BOOL,
> +        },{
> +            .name = "block",
> +            .type = QEMU_OPT_BOOL,
>          },
>          { /* end if list */ }
>      },
> @@ -194,7 +197,7 @@ listen:
>      return slisten;
>  }
>  
> -int inet_connect_opts(QemuOpts *opts)
> +int inet_connect_opts(QemuOpts *opts, Error **errp)
>  {
>      struct addrinfo ai,*res,*e;
>      const char *addr;
> @@ -202,6 +205,7 @@ int inet_connect_opts(QemuOpts *opts)
>      char uaddr[INET6_ADDRSTRLEN+1];
>      char uport[33];
>      int sock,rc;
> +    bool block;
>  
>      memset(&ai,0, sizeof(ai));
>      ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
> @@ -210,8 +214,10 @@ int inet_connect_opts(QemuOpts *opts)
>  
>      addr = qemu_opt_get(opts, "host");
>      port = qemu_opt_get(opts, "port");
> +    block = qemu_opt_get_bool(opts, "block", 0);
>      if (addr == NULL || port == NULL) {
>          fprintf(stderr, "inet_connect: host and/or port not specified\n");
> +        error_set(errp, QERR_SOCKET_CREATE_FAILED);
>          return -1;
>      }
>  
> @@ -224,6 +230,7 @@ int inet_connect_opts(QemuOpts *opts)
>      if (0 != (rc = getaddrinfo(addr, port, &ai, &res))) {
>          fprintf(stderr,"getaddrinfo(%s,%s): %s\n", addr, port,
>                  gai_strerror(rc));
> +        error_set(errp, QERR_SOCKET_CREATE_FAILED);
>  	return -1;
>      }
>  
> @@ -241,19 +248,40 @@ int inet_connect_opts(QemuOpts *opts)
>              continue;
>          }
>          setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(void*)&on,sizeof(on));
> -
> +        if (!block) {
> +            socket_set_nonblock(sock);
> +        }
>          /* connect to peer */
> -        if (connect(sock,e->ai_addr,e->ai_addrlen) < 0) {
> +        do {
> +            rc = 0;
> +            if (connect(sock, e->ai_addr, e->ai_addrlen) < 0) {
> +                rc = -socket_error();
> +            }
> +        } while (rc == -EINTR);
> +
> +  #ifdef _WIN32
> +        if (!block && (rc == -EINPROGRESS || rc == -EWOULDBLOCK
> +                       || rc == -WSAEALREADY)) {
> +  #else
> +        if (!block && (rc == -EINPROGRESS)) {
> +  #endif
> +            error_set(errp, QERR_SOCKET_CONNECT_IN_PROGRESS);
> +        }
> +        if (rc < 0 && (!errp || !error_is_type(*errp,
> +            QERR_SOCKET_CONNECT_IN_PROGRESS))) {
This is means we don't handle non-blocking correctly if errp is NULL.
I think this can work: 
else if (rc < 0) {

Orit
> +
>              if (NULL == e->ai_next)
>                  fprintf(stderr, "%s: connect(%s,%s,%s,%s): %s\n", __FUNCTION__,
>                          inet_strfamily(e->ai_family),
>                          e->ai_canonname, uaddr, uport, strerror(errno));
>              closesocket(sock);
> +            sock = -1;
>              continue;
>          }
>          freeaddrinfo(res);
>          return sock;
>      }
> +    error_set(errp, QERR_SOCKET_CONNECT_FAILED);
>      freeaddrinfo(res);
>      return -1;
>  }
> @@ -449,14 +477,20 @@ int inet_listen(const char *str, char *ostr, int olen,
>      return sock;
>  }
>  
> -int inet_connect(const char *str, int socktype)
> +int inet_connect(const char *str, bool block, Error **errp)
>  {
>      QemuOpts *opts;
>      int sock = -1;
>  
>      opts = qemu_opts_create(&dummy_opts, NULL, 0);
> -    if (inet_parse(opts, str) == 0)
> -        sock = inet_connect_opts(opts);
> +    if (inet_parse(opts, str) == 0) {
> +        if (block) {
> +            qemu_opt_set(opts, "block", "on");
> +        }
> +        sock = inet_connect_opts(opts, errp);
> +    } else {
> +        error_set(errp, QERR_SOCKET_CREATE_FAILED);
> +    }
>      qemu_opts_del(opts);
>      return sock;
>  }
> diff --git a/qemu_socket.h b/qemu_socket.h
> index a5d0a84..26998ef 100644
> --- a/qemu_socket.h
> +++ b/qemu_socket.h
> @@ -27,6 +27,8 @@ int inet_aton(const char *cp, struct in_addr *ia);
>  #endif /* !_WIN32 */
>  
>  #include "qemu-option.h"
> +#include "error.h"
> +#include "qerror.h"
>  
>  /* misc helpers */
>  int qemu_socket(int domain, int type, int protocol);
> @@ -40,8 +42,8 @@ int send_all(int fd, const void *buf, int len1);
>  int inet_listen_opts(QemuOpts *opts, int port_offset);
>  int inet_listen(const char *str, char *ostr, int olen,
>                  int socktype, int port_offset);
> -int inet_connect_opts(QemuOpts *opts);
> -int inet_connect(const char *str, int socktype);
> +int inet_connect_opts(QemuOpts *opts, Error **errp);
> +int inet_connect(const char *str, bool block, Error **errp);
>  int inet_dgram_opts(QemuOpts *opts);
>  const char *inet_strfamily(int family);
>  
> diff --git a/ui/vnc.c b/ui/vnc.c
> index deb9ecd..3ae7704 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -3068,7 +3068,7 @@ int vnc_display_open(DisplayState *ds, const char *display)
>          if (strncmp(display, "unix:", 5) == 0)
>              vs->lsock = unix_connect(display+5);
>          else
> -            vs->lsock = inet_connect(display, SOCK_STREAM);
> +            vs->lsock = inet_connect(display, true, NULL);
>          if (-1 == vs->lsock) {
>              g_free(vs->display);
>              vs->display = NULL;
> 
>
Amos Kong - April 25, 2012, 5:24 a.m.
On 25/04/12 13:00, Orit Wasserman wrote:
> On 04/25/2012 06:32 AM, Amos Kong wrote:
>> Add a bool argument to inet_connect() to assign if set socket
>> to block/nonblock, and delete original argument 'socktype'
>> that is unused.
>> Add a new argument to inet_connect()/inet_connect_opts(),
>> to pass back connect error by error class.
>>
>> Retry to connect when -EINTR is got. Connect's successful
>> for nonblock socket when following errors are got, user
>> should wait for connecting by select():
>>    -EINPROGRESS
>>    -EWOULDBLOCK (win32)
>>    -WSAEALREADY (win32)
>>
>> Change nbd, vnc to use new interface.
>>
>> Changes from v7:
>> - posix: let EWOULDBLOCK fall through to CONNECT_FAILED path
>> - fix typo
>>
>> Changes from v8:
>> - reuse rc variable
>> - fix a NULL pointer dereference
>>
>> Signed-off-by: Amos Kong<akong@redhat.com>
>> ---
>>   nbd.c          |    2 +-
>>   qemu-char.c    |    2 +-
>>   qemu-sockets.c |   46 ++++++++++++++++++++++++++++++++++++++++------
>>   qemu_socket.h  |    6 ++++--
>>   ui/vnc.c       |    2 +-
>>   5 files changed, 47 insertions(+), 11 deletions(-)
>>
>> diff --git a/nbd.c b/nbd.c
>> index 406e555..bb71f00 100644
>> --- a/nbd.c
>> +++ b/nbd.c
>> @@ -146,7 +146,7 @@ int tcp_socket_outgoing(const char *address, uint16_t port)
>>
>>   int tcp_socket_outgoing_spec(const char *address_and_port)
>>   {
>> -    return inet_connect(address_and_port, SOCK_STREAM);
>> +    return inet_connect(address_and_port, true, NULL);
>>   }
>>
>>   int tcp_socket_incoming(const char *address, uint16_t port)
>> diff --git a/qemu-char.c b/qemu-char.c
>> index 74c60e1..aeee2e8 100644
>> --- a/qemu-char.c
>> +++ b/qemu-char.c
>> @@ -2444,7 +2444,7 @@ static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
>>           if (is_listen) {
>>               fd = inet_listen_opts(opts, 0);
>>           } else {
>> -            fd = inet_connect_opts(opts);
>> +            fd = inet_connect_opts(opts, NULL);
>>           }
>>       }
>>       if (fd<  0) {
>> diff --git a/qemu-sockets.c b/qemu-sockets.c
>> index 6bcb8e3..243af67 100644
>> --- a/qemu-sockets.c
>> +++ b/qemu-sockets.c
>> @@ -51,6 +51,9 @@ static QemuOptsList dummy_opts = {
>>           },{
>>               .name = "ipv6",
>>               .type = QEMU_OPT_BOOL,
>> +        },{
>> +            .name = "block",
>> +            .type = QEMU_OPT_BOOL,
>>           },
>>           { /* end if list */ }
>>       },
>> @@ -194,7 +197,7 @@ listen:
>>       return slisten;
>>   }
>>
>> -int inet_connect_opts(QemuOpts *opts)
>> +int inet_connect_opts(QemuOpts *opts, Error **errp)
>>   {
>>       struct addrinfo ai,*res,*e;
>>       const char *addr;
>> @@ -202,6 +205,7 @@ int inet_connect_opts(QemuOpts *opts)
>>       char uaddr[INET6_ADDRSTRLEN+1];
>>       char uport[33];
>>       int sock,rc;
>> +    bool block;
>>
>>       memset(&ai,0, sizeof(ai));
>>       ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
>> @@ -210,8 +214,10 @@ int inet_connect_opts(QemuOpts *opts)
>>
>>       addr = qemu_opt_get(opts, "host");
>>       port = qemu_opt_get(opts, "port");
>> +    block = qemu_opt_get_bool(opts, "block", 0);
>>       if (addr == NULL || port == NULL) {
>>           fprintf(stderr, "inet_connect: host and/or port not specified\n");
>> +        error_set(errp, QERR_SOCKET_CREATE_FAILED);
>>           return -1;
>>       }
>>
>> @@ -224,6 +230,7 @@ int inet_connect_opts(QemuOpts *opts)
>>       if (0 != (rc = getaddrinfo(addr, port,&ai,&res))) {
>>           fprintf(stderr,"getaddrinfo(%s,%s): %s\n", addr, port,
>>                   gai_strerror(rc));
>> +        error_set(errp, QERR_SOCKET_CREATE_FAILED);
>>   	return -1;
>>       }
>>
>> @@ -241,19 +248,40 @@ int inet_connect_opts(QemuOpts *opts)
>>               continue;
>>           }
>>           setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(void*)&on,sizeof(on));
>> -
>> +        if (!block) {
>> +            socket_set_nonblock(sock);
>> +        }
>>           /* connect to peer */
>> -        if (connect(sock,e->ai_addr,e->ai_addrlen)<  0) {
>> +        do {
>> +            rc = 0;
>> +            if (connect(sock, e->ai_addr, e->ai_addrlen)<  0) {
>> +                rc = -socket_error();
>> +            }
>> +        } while (rc == -EINTR);
>> +
>> +  #ifdef _WIN32
>> +        if (!block&&  (rc == -EINPROGRESS || rc == -EWOULDBLOCK
>> +                       || rc == -WSAEALREADY)) {
>> +  #else
>> +        if (!block&&  (rc == -EINPROGRESS)) {
>> +  #endif
>> +            error_set(errp, QERR_SOCKET_CONNECT_IN_PROGRESS);
>> +        }
>> +        if (rc<  0&&  (!errp || !error_is_type(*errp,
>> +            QERR_SOCKET_CONNECT_IN_PROGRESS))) {
> This is means we don't handle non-blocking correctly if errp is NULL.
> I think this can work:
> else if (rc<  0) {

yes, it works. Have sent v10.

Thanks

> Orit
>> +
>>               if (NULL == e->ai_next)
>>                   fprintf(stderr, "%s: connect(%s,%s,%s,%s): %s\n", __FUNCTION__,
>>                           inet_strfamily(e->ai_family),
>>                           e->ai_canonname, uaddr, uport, strerror(errno));
>>               closesocket(sock);
>> +            sock = -1;
>>               continue;
>>           }
>>           freeaddrinfo(res);
>>           return sock;
>>       }
>> +    error_set(errp, QERR_SOCKET_CONNECT_FAILED);
>>       freeaddrinfo(res);
>>

...

Patch

diff --git a/nbd.c b/nbd.c
index 406e555..bb71f00 100644
--- a/nbd.c
+++ b/nbd.c
@@ -146,7 +146,7 @@  int tcp_socket_outgoing(const char *address, uint16_t port)
 
 int tcp_socket_outgoing_spec(const char *address_and_port)
 {
-    return inet_connect(address_and_port, SOCK_STREAM);
+    return inet_connect(address_and_port, true, NULL);
 }
 
 int tcp_socket_incoming(const char *address, uint16_t port)
diff --git a/qemu-char.c b/qemu-char.c
index 74c60e1..aeee2e8 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -2444,7 +2444,7 @@  static CharDriverState *qemu_chr_open_socket(QemuOpts *opts)
         if (is_listen) {
             fd = inet_listen_opts(opts, 0);
         } else {
-            fd = inet_connect_opts(opts);
+            fd = inet_connect_opts(opts, NULL);
         }
     }
     if (fd < 0) {
diff --git a/qemu-sockets.c b/qemu-sockets.c
index 6bcb8e3..243af67 100644
--- a/qemu-sockets.c
+++ b/qemu-sockets.c
@@ -51,6 +51,9 @@  static QemuOptsList dummy_opts = {
         },{
             .name = "ipv6",
             .type = QEMU_OPT_BOOL,
+        },{
+            .name = "block",
+            .type = QEMU_OPT_BOOL,
         },
         { /* end if list */ }
     },
@@ -194,7 +197,7 @@  listen:
     return slisten;
 }
 
-int inet_connect_opts(QemuOpts *opts)
+int inet_connect_opts(QemuOpts *opts, Error **errp)
 {
     struct addrinfo ai,*res,*e;
     const char *addr;
@@ -202,6 +205,7 @@  int inet_connect_opts(QemuOpts *opts)
     char uaddr[INET6_ADDRSTRLEN+1];
     char uport[33];
     int sock,rc;
+    bool block;
 
     memset(&ai,0, sizeof(ai));
     ai.ai_flags = AI_CANONNAME | AI_ADDRCONFIG;
@@ -210,8 +214,10 @@  int inet_connect_opts(QemuOpts *opts)
 
     addr = qemu_opt_get(opts, "host");
     port = qemu_opt_get(opts, "port");
+    block = qemu_opt_get_bool(opts, "block", 0);
     if (addr == NULL || port == NULL) {
         fprintf(stderr, "inet_connect: host and/or port not specified\n");
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
         return -1;
     }
 
@@ -224,6 +230,7 @@  int inet_connect_opts(QemuOpts *opts)
     if (0 != (rc = getaddrinfo(addr, port, &ai, &res))) {
         fprintf(stderr,"getaddrinfo(%s,%s): %s\n", addr, port,
                 gai_strerror(rc));
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
 	return -1;
     }
 
@@ -241,19 +248,40 @@  int inet_connect_opts(QemuOpts *opts)
             continue;
         }
         setsockopt(sock,SOL_SOCKET,SO_REUSEADDR,(void*)&on,sizeof(on));
-
+        if (!block) {
+            socket_set_nonblock(sock);
+        }
         /* connect to peer */
-        if (connect(sock,e->ai_addr,e->ai_addrlen) < 0) {
+        do {
+            rc = 0;
+            if (connect(sock, e->ai_addr, e->ai_addrlen) < 0) {
+                rc = -socket_error();
+            }
+        } while (rc == -EINTR);
+
+  #ifdef _WIN32
+        if (!block && (rc == -EINPROGRESS || rc == -EWOULDBLOCK
+                       || rc == -WSAEALREADY)) {
+  #else
+        if (!block && (rc == -EINPROGRESS)) {
+  #endif
+            error_set(errp, QERR_SOCKET_CONNECT_IN_PROGRESS);
+        }
+        if (rc < 0 && (!errp || !error_is_type(*errp,
+            QERR_SOCKET_CONNECT_IN_PROGRESS))) {
+
             if (NULL == e->ai_next)
                 fprintf(stderr, "%s: connect(%s,%s,%s,%s): %s\n", __FUNCTION__,
                         inet_strfamily(e->ai_family),
                         e->ai_canonname, uaddr, uport, strerror(errno));
             closesocket(sock);
+            sock = -1;
             continue;
         }
         freeaddrinfo(res);
         return sock;
     }
+    error_set(errp, QERR_SOCKET_CONNECT_FAILED);
     freeaddrinfo(res);
     return -1;
 }
@@ -449,14 +477,20 @@  int inet_listen(const char *str, char *ostr, int olen,
     return sock;
 }
 
-int inet_connect(const char *str, int socktype)
+int inet_connect(const char *str, bool block, Error **errp)
 {
     QemuOpts *opts;
     int sock = -1;
 
     opts = qemu_opts_create(&dummy_opts, NULL, 0);
-    if (inet_parse(opts, str) == 0)
-        sock = inet_connect_opts(opts);
+    if (inet_parse(opts, str) == 0) {
+        if (block) {
+            qemu_opt_set(opts, "block", "on");
+        }
+        sock = inet_connect_opts(opts, errp);
+    } else {
+        error_set(errp, QERR_SOCKET_CREATE_FAILED);
+    }
     qemu_opts_del(opts);
     return sock;
 }
diff --git a/qemu_socket.h b/qemu_socket.h
index a5d0a84..26998ef 100644
--- a/qemu_socket.h
+++ b/qemu_socket.h
@@ -27,6 +27,8 @@  int inet_aton(const char *cp, struct in_addr *ia);
 #endif /* !_WIN32 */
 
 #include "qemu-option.h"
+#include "error.h"
+#include "qerror.h"
 
 /* misc helpers */
 int qemu_socket(int domain, int type, int protocol);
@@ -40,8 +42,8 @@  int send_all(int fd, const void *buf, int len1);
 int inet_listen_opts(QemuOpts *opts, int port_offset);
 int inet_listen(const char *str, char *ostr, int olen,
                 int socktype, int port_offset);
-int inet_connect_opts(QemuOpts *opts);
-int inet_connect(const char *str, int socktype);
+int inet_connect_opts(QemuOpts *opts, Error **errp);
+int inet_connect(const char *str, bool block, Error **errp);
 int inet_dgram_opts(QemuOpts *opts);
 const char *inet_strfamily(int family);
 
diff --git a/ui/vnc.c b/ui/vnc.c
index deb9ecd..3ae7704 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3068,7 +3068,7 @@  int vnc_display_open(DisplayState *ds, const char *display)
         if (strncmp(display, "unix:", 5) == 0)
             vs->lsock = unix_connect(display+5);
         else
-            vs->lsock = inet_connect(display, SOCK_STREAM);
+            vs->lsock = inet_connect(display, true, NULL);
         if (-1 == vs->lsock) {
             g_free(vs->display);
             vs->display = NULL;