0000

server-exp4/common.c

@@ -0,0 +1,170 @@
+/* $begin common.c */
+#include "common.h"
+
+/*********************************************************************
+ * The Rio package - robust I/O functions
+ **********************************************************************/
+
+ssize_t rio_readn(int fd, void *usrbuf, size_t n)
+{
+    size_t nleft = n;
+    ssize_t nread;
+    char *bufp = usrbuf;
+
+    while (nleft > 0) {
+        if ((nread = read(fd, bufp, nleft)) < 0) {
+            if (errno == EINTR)
+                nread = 0;
+            else
+                return -1;
+        }
+        else if (nread == 0)
+            break;
+        nleft -= nread;
+        bufp += nread;
+    }
+    return (n - nleft);
+}
+
+ssize_t rio_writen(int fd, void *usrbuf, size_t n)
+{
+    size_t nleft = n;
+    ssize_t nwritten;
+    char *bufp = usrbuf;
+
+    while (nleft > 0) {
+        if ((nwritten = write(fd, bufp, nleft)) <= 0) {
+            if (errno == EINTR)
+                nwritten = 0;
+            else
+                return -1;
+        }
+        nleft -= nwritten;
+        bufp += nwritten;
+    }
+    return n;
+}
+
+static ssize_t rio_read(rio_t *rp, char *usrbuf, size_t n)
+{
+    int cnt;
+    while (rp->rio_cnt <= 0) {
+        rp->rio_cnt = read(rp->rio_fd, rp->rio_buf,
+                   sizeof(rp->rio_buf));
+        if (rp->rio_cnt < 0) {
+            if (errno != EINTR)
+                return -1;
+        }
+        else if (rp->rio_cnt == 0)
+            return 0;
+        else
+            rp->rio_bufptr = rp->rio_buf;
+    }
+    cnt = n;
+    if (rp->rio_cnt < n)
+        cnt = rp->rio_cnt;
+    memcpy(usrbuf, rp->rio_bufptr, cnt);
+    rp->rio_bufptr += cnt;
+    rp->rio_cnt -= cnt;
+    return cnt;
+}
+
+void rio_readinitb(rio_t *rp, int fd)
+{
+    rp->rio_fd = fd;
+    rp->rio_cnt = 0;
+    rp->rio_bufptr = rp->rio_buf;
+}
+
+ssize_t rio_readnb(rio_t *rp, void *usrbuf, size_t n)
+{
+    size_t nleft = n;
+    ssize_t nread;
+    char *bufp = usrbuf;
+
+    while (nleft > 0) {
+        if ((nread = rio_read(rp, bufp, nleft)) < 0) {
+            if (errno == EINTR)
+                nread = 0;
+            else
+                return -1;
+        }
+        else if (nread == 0)
+            break;
+        nleft -= nread;
+        bufp += nread;
+    }
+    return (n - nleft);
+}
+
+ssize_t rio_readlineb(rio_t *rp, void *usrbuf, size_t maxlen)
+{
+    int n, rc;
+    char c, *bufp = usrbuf;
+
+    for (n = 1; n < maxlen; n++) {
+        if ((rc = rio_read(rp, &c, 1)) == 1) {
+            *bufp++ = c;
+            if (c == '\n')
+                break;
+        } else if (rc == 0) {
+            if (n == 1)
+                return 0;
+            else
+                break;
+        } else
+            return -1;
+    }
+    *bufp = 0;
+    return n;
+}
+
+/********************************
+ * Client/server helper functions
+ ********************************/
+
+int open_client_sock(char *hostname, int port)
+{
+    int client_sock;
+    struct hostent *hp;
+    struct sockaddr_in serveraddr;
+
+    if ((client_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+        return -1;
+
+    if ((hp = gethostbyname(hostname)) == NULL)
+        return -2;
+    bzero((char *) &serveraddr, sizeof(serveraddr));
+    serveraddr.sin_family = AF_INET;
+    bcopy((char *)hp->h_addr_list[0],
+          (char *)&serveraddr.sin_addr.s_addr, hp->h_length);
+    serveraddr.sin_port = htons(port);
+
+    if (connect(client_sock, (SA *) &serveraddr, sizeof(serveraddr)) < 0)
+        return -1;
+    return client_sock;
+}
+
+int open_listen_sock(int port)
+{
+    int listen_sock, optval=1;
+    struct sockaddr_in serveraddr;
+
+    if ((listen_sock = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+        return -1;
+
+    if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
+               (const void *)&optval , sizeof(int)) < 0)
+        return -1;
+
+    bzero((char *) &serveraddr, sizeof(serveraddr));
+    serveraddr.sin_family = AF_INET;
+    serveraddr.sin_addr.s_addr = htonl(INADDR_ANY);
+    serveraddr.sin_port = htons((unsigned short)port);
+    if (bind(listen_sock, (SA *)&serveraddr, sizeof(serveraddr)) < 0)
+        return -1;
+
+    if (listen(listen_sock, LISTENQ) < 0)
+        return -1;
+    return listen_sock;
+}