Rewrite nc to be simpler, smaller, and to check syscalls for errors.

diff --git a/busybox.h b/busybox.h
index 41421ae56d80cb8b44bdb9462ac2f1ab07b3a437..5ff3975b9ae1ad9d8d06f7a3fbe68ef729e5d3da 100644 (file)
--- a/busybox.h
+++ b/busybox.h
@@ -147,6 +147,7 @@ int makeString(int argc, const char **argv, char *buf, int bufLen);
 char *getChunk(int size);
 char *chunkstrdup(const char *str);
 void freeChunks(void);
+ssize_t safe_read(int fd, void *buf, size_t count);
 int full_write(int fd, const char *buf, int len);
 int full_read(int fd, char *buf, int len);
 int recursive_action(const char *fileName, int recurse, int followLinks, int depthFirst,

diff --git a/include/busybox.h b/include/busybox.h
index 41421ae56d80cb8b44bdb9462ac2f1ab07b3a437..5ff3975b9ae1ad9d8d06f7a3fbe68ef729e5d3da 100644 (file)
--- a/include/busybox.h
+++ b/include/busybox.h
@@ -147,6 +147,7 @@ int makeString(int argc, const char **argv, char *buf, int bufLen);
 char *getChunk(int size);
 char *chunkstrdup(const char *str);
 void freeChunks(void);
+ssize_t safe_read(int fd, void *buf, size_t count);
 int full_write(int fd, const char *buf, int len);
 int full_read(int fd, char *buf, int len);
 int recursive_action(const char *fileName, int recurse, int followLinks, int depthFirst,

diff --git a/nc.c b/nc.c
index 84c1a815eddcf6aac40d777a0992e6d04c9dda0d..a2be8ec46dbb87a48eb4898912d85f82c6daa6b6 100644 (file)
--- a/nc.c
+++ b/nc.c
@@ -38,14 +38,10 @@
 #include <sys/time.h>
 #include <sys/ioctl.h>
 
-#define BUFSIZE 100
-
 int nc_main(int argc, char **argv)
 {
        int sfd;
-       int result;
-       int len;
-       char ch[BUFSIZE];
+       char buf[BUFSIZ];
 
        struct sockaddr_in address;
        struct hostent *hostinfo;
@@ -54,34 +50,26 @@ int nc_main(int argc, char **argv)
 
        argc--;
        argv++;
-       if (argc < 2 || **(argv + 1) == '-') {
+       if (argc < 2 || **argv == '-') {
                usage(nc_usage);
        }
 
-       sfd = socket(AF_INET, SOCK_STREAM, 0);
-
-       hostinfo = (struct hostent *) gethostbyname(*argv);
+       if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+               perror_msg_and_die("socket");
 
-       if (!hostinfo) {
+       if ((hostinfo = gethostbyname(*argv)) == NULL)
                error_msg_and_die("cannot resolve %s\n", *argv);
-       }
 
        address.sin_family = AF_INET;
        address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
        address.sin_port = htons(atoi(*(++argv)));
 
-       len = sizeof(address);
-
-       result = connect(sfd, (struct sockaddr *) &address, len);
-
-       if (result < 0) {
-               perror("nc: connect");
-               exit(2);
-       }
+       if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+               perror_msg_and_die("connect");
 
        FD_ZERO(&readfds);
        FD_SET(sfd, &readfds);
-       FD_SET(fileno(stdin), &readfds);
+       FD_SET(STDIN_FILENO, &readfds);
 
        while (1) {
                int fd;
@@ -90,41 +78,26 @@ int nc_main(int argc, char **argv)
 
                testfds = readfds;
 
-               result =
-                       select(FD_SETSIZE, &testfds, (fd_set *) NULL, (fd_set *) NULL,
-                                  (struct timeval *) 0);
-
-               if (result < 1) {
-                       perror("nc: select");
-                       exit(3);
-               }
+               if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
+                       perror_msg_and_die("select");
 
                for (fd = 0; fd < FD_SETSIZE; fd++) {
                        if (FD_ISSET(fd, &testfds)) {
-                               int trn = 0;
-                               int rn;
-
-                               ioctl(fd, FIONREAD, &nread);
+                               if ((nread = safe_read(fd, buf, sizeof(buf))) < 0)
+                                       perror_msg_and_die("read");
 
                                if (fd == sfd) {
                                        if (nread == 0)
                                                exit(0);
-                                       ofd = fileno(stdout);
+                                       ofd = STDOUT_FILENO;
                                } else {
                                        if (nread == 0)
                                                shutdown(sfd, 1);
                                        ofd = sfd;
                                }
 
-
-
-                               do {
-                                       rn = (BUFSIZE < nread - trn) ? BUFSIZE : nread - trn;
-                                       trn += rn;
-                                       read(fd, ch, rn);
-                                       write(ofd, ch, rn);
-                               }
-                               while (trn < nread);
+                               if (full_write(ofd, buf, nread) < 0)
+                                       perror_msg_and_die("write");
                        }
                }
        }

diff --git a/networking/nc.c b/networking/nc.c
index 84c1a815eddcf6aac40d777a0992e6d04c9dda0d..a2be8ec46dbb87a48eb4898912d85f82c6daa6b6 100644 (file)
--- a/networking/nc.c
+++ b/networking/nc.c
@@ -38,14 +38,10 @@
 #include <sys/time.h>
 #include <sys/ioctl.h>
 
-#define BUFSIZE 100
-
 int nc_main(int argc, char **argv)
 {
        int sfd;
-       int result;
-       int len;
-       char ch[BUFSIZE];
+       char buf[BUFSIZ];
 
        struct sockaddr_in address;
        struct hostent *hostinfo;
@@ -54,34 +50,26 @@ int nc_main(int argc, char **argv)
 
        argc--;
        argv++;
-       if (argc < 2 || **(argv + 1) == '-') {
+       if (argc < 2 || **argv == '-') {
                usage(nc_usage);
        }
 
-       sfd = socket(AF_INET, SOCK_STREAM, 0);
-
-       hostinfo = (struct hostent *) gethostbyname(*argv);
+       if ((sfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
+               perror_msg_and_die("socket");
 
-       if (!hostinfo) {
+       if ((hostinfo = gethostbyname(*argv)) == NULL)
                error_msg_and_die("cannot resolve %s\n", *argv);
-       }
 
        address.sin_family = AF_INET;
        address.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list;
        address.sin_port = htons(atoi(*(++argv)));
 
-       len = sizeof(address);
-
-       result = connect(sfd, (struct sockaddr *) &address, len);
-
-       if (result < 0) {
-               perror("nc: connect");
-               exit(2);
-       }
+       if (connect(sfd, (struct sockaddr *) &address, sizeof(address)) < 0)
+               perror_msg_and_die("connect");
 
        FD_ZERO(&readfds);
        FD_SET(sfd, &readfds);
-       FD_SET(fileno(stdin), &readfds);
+       FD_SET(STDIN_FILENO, &readfds);
 
        while (1) {
                int fd;
@@ -90,41 +78,26 @@ int nc_main(int argc, char **argv)
 
                testfds = readfds;
 
-               result =
-                       select(FD_SETSIZE, &testfds, (fd_set *) NULL, (fd_set *) NULL,
-                                  (struct timeval *) 0);
-
-               if (result < 1) {
-                       perror("nc: select");
-                       exit(3);
-               }
+               if (select(FD_SETSIZE, &testfds, NULL, NULL, NULL) < 0)
+                       perror_msg_and_die("select");
 
                for (fd = 0; fd < FD_SETSIZE; fd++) {
                        if (FD_ISSET(fd, &testfds)) {
-                               int trn = 0;
-                               int rn;
-
-                               ioctl(fd, FIONREAD, &nread);
+                               if ((nread = safe_read(fd, buf, sizeof(buf))) < 0)
+                                       perror_msg_and_die("read");
 
                                if (fd == sfd) {
                                        if (nread == 0)
                                                exit(0);
-                                       ofd = fileno(stdout);
+                                       ofd = STDOUT_FILENO;
                                } else {
                                        if (nread == 0)
                                                shutdown(sfd, 1);
                                        ofd = sfd;
                                }
 
-
-
-                               do {
-                                       rn = (BUFSIZE < nread - trn) ? BUFSIZE : nread - trn;
-                                       trn += rn;
-                                       read(fd, ch, rn);
-                                       write(ofd, ch, rn);
-                               }
-                               while (trn < nread);
+                               if (full_write(ofd, buf, nread) < 0)
+                                       perror_msg_and_die("write");
                        }
                }
        }

diff --git a/utility.c b/utility.c
index 02479d9773fa0bce6e421d6e32963dfc614e2699..4654daec4484791ae3b722f3cc4f4339318a7420 100644 (file)
--- a/utility.c
+++ b/utility.c
@@ -536,7 +536,7 @@ const char *time_string(time_t timeVal)
 }
 #endif /* BB_TAR || BB_AR */
 
-#if defined BB_TAR || defined BB_CP_MV || defined BB_AR || defined BB_DD
+#if defined BB_AR || defined BB_CP_MV || defined BB_DD || defined BB_NC || defined BB_TAR
 /*
  * Write all of the supplied buffer out to a file.
  * This does multiple writes as necessary.
@@ -1791,6 +1791,19 @@ int applet_name_compare(const void *x, const void *y)
        return strcmp(applet1->name, applet2->name);
 }
 
+#if defined BB_NC
+ssize_t safe_read(int fd, void *buf, size_t count)
+{
+       ssize_t n;
+
+       do {
+               n = read(fd, buf, count);
+       } while (n < 0 && errno == EINTR);
+
+       return n;
+}
+#endif
+
 /* END CODE */
 /*
 Local Variables: