How convert/put the char* variable into struct sockaddr? - c++

Question

Hi
I have a problem with giving a name to socket by a program parameter.
I tried do it in many ways, some conversions (strcpy function)etc. but in the best option it gives me a one letter from my name. How can I convert/put it into that structure?
void socket_out(char* name)
{
int listfd;
int connfd;
listfd = socket(AF_UNIX, SOCK_STREAM, 0);
if(listfd == -1)
exit(-1);
struct sockaddr saddr = {AF_UNIX, name};
socklen_t saddrlen = sizeof(struct sockaddr) + 6;
bind(listfd, &saddr, saddrlen);
And error:
error: invalid conversion from ‘char*’ to ‘char’ [-fpermissive]
struct sockaddr saddr = {AF_UNIX, name};

Answer 1

Sorry, I just realized my previous answer was out of topic, as you seem to use Unix Domain Sockets, not TCP/IP sockets.
The problem is that you should never use struct sockaddr directly, but rather one of its "specializations", in this case struct sockaddr_un, and then cast it at the last minute. Have a look at the following example:
unsigned int s, s2;
struct sockaddr_un local, remote;
int len;
s = socket(AF_UNIX, SOCK_STREAM, 0);
local.sun_family = AF_UNIX;
strcpy(local.sun_path, "/home/beej/mysocket");
unlink(local.sun_path);
len = strlen(local.sun_path) + sizeof(local.sun_family);
bind(s, (struct sockaddr *)&local, len);
Taken from the excellent Beej's Guide to Unix IPC: http://beej.us/guide/bgipc/output/html/multipage/unixsock.html

Answer 2

you are tying to initialize a structure there, but the second parameter is not of type char*, but of type char[].
See the definition for struct sockaddr:
The <sys/socket.h> header shall define the sockaddr structure that includes at least the following members:
sa_family_t sa_family Address family.
char sa_data[] Socket address (variable-length data).
To get around that, you have to use strcpy/strncpy for the second parameter:
struct sockaddr saddr;
saddr.sun_family = AF_UNIX;
strncpy(saddr.sun_path, name, UNIX_PATH_MAX);
addr.sun_path[UNIX_PATH_MAX - 1] = '\0';