connect to socket failed - errno 88 (cpp)

Question

I'm trying to create server/client communication and it faileson the connect function with errno 88. I checked if the socketfd is valid (because this errno means that I'm trying to make socket operation on non socket object).

int main (int argc, char *argv[])
{
// Validity check
if (argc != VALID_ARG_NUM) {
    std::cout << INVALID_ARG;
    return 0; // todo - return 0 is correct??
}

int port;
struct sockaddr_in server_address;

// server_address initialization.
server_address.sin_family = AF_INET;
server_address.sin_port = htons((uint32_t)atof(argv[3]));
server_address.sin_addr.s_addr = inet_addr(argv[2]);
memset(&(server_address.sin_zero), '\0', sizeof(server_address));

// Create the client socket.
if (sockfd = socket(AF_INET, SOCK_STREAM, 0) < 0) {
    std::cout << "ERROR: socket " << errno << "." << std::endl;
    exit(1);
}
// Connect to server.
if (connect(sockfd, (struct sockaddr *)&server_address, sizeof(server_address)) < 0) {
    std::cout << "ERROR: connect " << errno << "." << std::endl;
    std::cout << CON_FAIL;
    close(sockfd);
    exit(1);
}
.......

thank you.

If you have Boost available, or are able to download it, I would highly recommend using Boost Asio for socket programming. — , Jun 20 '17 at 13:08
The error codes in `errno` are really platform dependent. Please tell us which platform (operating system) you use. And use e.g. `strerror` to get a printable string from the error code. — Some programmer dude, Jun 20 '17 at 13:09
ok, I changed it like you told me, and it still stuck - with broken pipe.. — Michal Shalom, Jun 20 '17 at 13:22
Possible duplicate of [Bind return error 88](https://stackoverflow.com/questions/28124746/bind-return-error-88) — mpromonet, May 30 '18 at 20:55

score 1 · Answer 1 · answered Jun 20 '17 at 13:09

1

I think this part is causing buffer overrun:

memset(&(server_address.sin_zero), '\0', sizeof(server_address));

You should zero the whole struct before writing somefields:

struct sockaddr_in server_address;
// server_address initialization.
memset(&server_address, 0, sizeof(server_address));
server_address.sin_family = AF_INET;

answered Jun 20 '17 at 13:09

user7860670

35,849
4
58
84

I changed it, and still errno 88 :/ – Michal Shalom Jun 20 '17 at 13:12

score 1 · Accepted Answer · answered Jun 20 '17 at 13:10

1

The precedence of the statement

sockfd = socket(AF_INET, SOCK_STREAM, 0) < 0

is

sockfd = ((socket(AF_INET, SOCK_STREAM, 0)) < 0)

and you are therefore assigning a boolean, which is implicitly converted to an integer (or whatever type sockfd has). What you probably meant was instead

(sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0

answered Jun 20 '17 at 13:10

You

22,800
3
51
64

ok, I changed it like you told me, and it still stuck - with broken pipe.. – Michal Shalom Jun 20 '17 at 13:26
@MichalShalom: Well, that is [an entirely different problem](https://stackoverflow.com/q/4584904/147845). – You Jun 20 '17 at 13:27

score 0 · Answer 3 · answered Jun 20 '17 at 15:03

0

Broken pipe usually means that remote peer closes connection. Are you sure your server code is OK? Maybe it just do something like this?

int main()
{
...
listen();
accept();

return 0;//procees exits and therefore brakes connection
}

answered Jun 20 '17 at 15:03

vatosarmat

1,090
10
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connect to socket failed - errno 88 (cpp)

3 Answers3