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#include <string.h> |
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#include <errno.h> |
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#include <unistd.h> |
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#include <sys/time.h> |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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#include <netdb.h> |
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#include <fcntl.h> |
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|
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#include "config.h" |
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#include "imapfilter.h" |
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|
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#ifdef SSL_TLS |
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#include <openssl/ssl.h> |
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#include <openssl/err.h> |
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#include <openssl/x509.h> |
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#endif |
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|
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|
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long timeout = -1; /* Server non-response timeout in seconds. */ |
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|
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static int sock; |
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|
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#ifdef SSL_TLS |
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static SSL *ssl; |
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#endif |
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|
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|
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/* |
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* Connect to mail server. |
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*/ |
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int init_connection(char *serv, unsigned short int port, |
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unsigned int protocol) |
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{ |
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struct sockaddr_in sa; |
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struct hostent *he; |
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|
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#ifndef SSL_TLS |
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if (protocol != SSL_DISABLED) { |
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error("imapfilter: SSL not supported by this build\n"); |
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return ERROR_SSL; |
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} |
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#endif |
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|
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memset((char *) &sa, 0, sizeof(struct sockaddr_in)); |
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|
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sock = socket(PF_INET, SOCK_STREAM, 0); |
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|
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if (sock < 0) { |
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error("imapfilter: create socket; %s\n", strerror(errno)); |
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return ERROR_NETWORK; |
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} |
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if (!(he = gethostbyname(serv))) { |
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error("imapfilter: get network host entry of %s; %s\n", serv, |
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strerror(errno)); |
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close_connection(); |
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return ERROR_NETWORK; |
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} |
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sa.sin_family = AF_INET; |
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sa.sin_port = htons(port); |
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sa.sin_addr = *(struct in_addr *) he->h_addr; |
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|
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xstrncpy(serv, he->h_name, SERVER_LEN - 1); |
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|
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if (connect(sock, (struct sockaddr *) & sa, sizeof(struct sockaddr))) { |
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error("imapfilter: initiating connection to %s; %s\n", serv, |
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strerror(errno)); |
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close_connection(); |
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return ERROR_NETWORK; |
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} |
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log_info(LOG_SERVER, serv); |
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|
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#ifdef SSL_TLS |
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if (protocol != SSL_DISABLED) |
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if (!ssl_init(protocol)) { |
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info("Connected to %s using %s.\n", serv, SSL_get_cipher(ssl)); |
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return 0; |
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} else |
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return ERROR_SSL; |
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else |
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ssl = NULL; |
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#endif |
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|
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info("Connected to %s.\n", serv); |
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|
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return 0; |
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} |
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|
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|
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#ifdef SSL_TLS |
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/* |
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* Initialize Secure Socket Layer connection. |
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*/ |
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int ssl_init(unsigned int protocol) |
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{ |
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int e; |
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unsigned int i, n = 0; |
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SSL_CTX *ctx; |
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SSL_METHOD *method = NULL; |
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X509 *cert; |
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char *c; |
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EVP_MD *evp; |
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unsigned char digest[EVP_MAX_MD_SIZE]; |
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|
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SSL_library_init(); |
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|
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switch (protocol) { |
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case SSL_SSL_V2: |
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method = SSLv2_client_method(); |
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break; |
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case SSL_SSL_V3: |
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method = SSLv3_client_method(); |
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break; |
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case SSL_TLS_V1: |
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method = TLSv1_client_method(); |
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break; |
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} |
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|
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if (!(ctx = SSL_CTX_new(method))) |
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return ERROR_SSL; |
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|
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if (!(ssl = SSL_new(ctx))) |
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return ERROR_SSL; |
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|
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SSL_set_fd(ssl, sock); |
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|
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e = SSL_connect(ssl); |
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|
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if (e < 0) { |
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error("imapfilter: initiating SSL connection; %s", |
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ERR_error_string(e, NULL)); |
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return ERROR_SSL; |
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} |
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/* Get server's certificate. */ |
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if (!(cert = SSL_get_peer_certificate(ssl))) |
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return ERROR_SSL; |
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|
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if (!(c = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0))) |
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return ERROR_SSL; |
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verbose("Server certificate subject: %s\n", c); |
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xfree(c); |
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|
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if (!(c = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0))) |
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return ERROR_SSL; |
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verbose("Server certificate issuer: %s\n", c); |
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xfree(c); |
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|
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if (!(evp = EVP_md5())) |
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return ERROR_SSL; |
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if (!(X509_digest(cert, evp, digest, &n))) |
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return ERROR_SSL; |
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|
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verbose("Server key fingerprint: "); |
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for (i = 0; i < n; i++) |
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verbose(i != n - 1 ? "%02X:" : "%02X\n", digest[i]); |
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|
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X509_free(cert); |
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SSL_CTX_free(ctx); |
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|
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return 0; |
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} |
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#endif |
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|
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|
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/* |
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* Disconnect from mail server. |
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*/ |
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int close_connection(void) |
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{ |
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#ifdef SSL_TLS |
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if (ssl) { |
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SSL_shutdown(ssl); |
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SSL_free(ssl); |
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} |
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#endif |
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|
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if (sock >= 0 && close(sock)) { |
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error("imapfilter: closing socket; %s\n", strerror(errno)); |
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return ERROR_NETWORK; |
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} else { |
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sock = -1; |
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return 0; |
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} |
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} |
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|
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|
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/* |
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* Read data from socket. |
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*/ |
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int socket_read(char *buf) |
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{ |
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int flags, r, s; |
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fd_set fds; |
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struct timeval tv; |
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struct timeval *tvp = NULL; |
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|
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r = 0; |
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s = 1; |
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|
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memset(buf, 0, RESPONSE_BUF); |
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|
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if (timeout >= 0) { |
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tv.tv_sec = timeout; |
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tv.tv_usec = 0; |
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tvp = &tv; |
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} |
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flags = fcntl(sock, F_GETFL, 0); |
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fcntl(sock, F_SETFL, flags | O_NONBLOCK); |
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|
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FD_ZERO(&fds); |
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FD_SET(sock, &fds); |
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|
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#ifdef SSL_TLS |
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if (ssl) { |
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if (SSL_pending(ssl) |
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|| ((s = select(sock + 1, &fds, NULL, NULL, tvp)) > 0 |
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&& FD_ISSET(sock, &fds))) |
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r = SSL_read(ssl, buf, RESPONSE_BUF - 1); |
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} else |
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#endif |
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if ((s = select(sock + 1, &fds, NULL, NULL, tvp)) > 0 |
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&& FD_ISSET(sock, &fds)) |
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r = read(sock, buf, RESPONSE_BUF - 1); |
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|
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fcntl(sock, F_SETFL, flags); |
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|
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if (s == -1) |
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fatal(ERROR_NETWORK, "imapfilter: waiting input from socket; %s\n", |
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strerror(errno)); |
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else if (!s) |
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fatal(ERROR_NETWORK, |
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"imapfilter: timeout period expired while waiting data\n"); |
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|
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#ifdef SSL_TLS |
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if (ssl) { |
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if (r < 0) |
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fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
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ERR_error_string(r, NULL)); |
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} else |
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#endif |
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if (r == -1) |
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fatal(ERROR_NETWORK, "imapfilter: reading data; %s", |
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strerror(errno)); |
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|
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return 0; |
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} |
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|
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|
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/* |
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* Write data to socket. |
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*/ |
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int socket_write(char *data) |
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{ |
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#ifdef SSL_TLS |
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int e; |
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|
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if (ssl) { |
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e = SSL_write(ssl, data, strlen(data)); |
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if (e <= 0) |
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fatal(ERROR_NETWORK, |
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"imapfilter: sending data; %s", |
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ERR_error_string(e, NULL)); |
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} else |
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#endif |
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if (write(sock, data, strlen(data)) == -1) |
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fatal(ERROR_NETWORK, "imapfilter: sending data; %s", |
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strerror(errno)); |
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|
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return 0; |
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} |
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