From e6dc439b3a3fa2a64f9e938ac4e5810025c04242 Mon Sep 17 00:00:00 2001 From: Eric Andersen Date: Fri, 31 Oct 2003 09:31:46 +0000 Subject: [PATCH] Rework wget, the xconnect interface, and its various clients in order to fix the problems with round robin DNS reported by Andrew Flegg: http://busybox.net/lists/busybox/2003-October/009579.html This removes the ipv6 specific xconnect dns lookups. I do not see why that would need to be special cased for ipv6 as was done, but that will just have to be tested. So IPV6 people -- please test this change! -Erik --- include/libbb.h | 8 ++-- libbb/safe_write.c | 2 +- libbb/xconnect.c | 98 ++++++++++++++++++++------------------------- networking/telnet.c | 4 +- networking/wget.c | 30 +++++++++----- util-linux/rdate.c | 7 ++-- 6 files changed, 76 insertions(+), 73 deletions(-) diff --git a/include/libbb.h b/include/libbb.h index 7587a407c..53062de4d 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -109,9 +109,9 @@ extern int is_directory(const char *name, int followLinks, struct stat *statBuf) extern int remove_file(const char *path, int flags); extern int copy_file(const char *source, const char *dest, int flags); extern ssize_t safe_read(int fd, void *buf, size_t count); -extern ssize_t safe_write(int fd, void *buf, size_t count); -extern ssize_t bb_full_write(int fd, const void *buf, size_t len); extern ssize_t bb_full_read(int fd, void *buf, size_t len); +extern ssize_t safe_write(int fd, const void *buf, size_t count); +extern ssize_t bb_full_write(int fd, const void *buf, size_t len); extern int recursive_action(const char *fileName, int recurse, int followLinks, int depthFirst, int (*fileAction) (const char *fileName, struct stat* statbuf, void* userData), @@ -294,7 +294,9 @@ extern struct hostent *xgethostbyname(const char *name); extern struct hostent *xgethostbyname2(const char *name, int af); extern int create_icmp_socket(void); extern int create_icmp6_socket(void); -extern int xconnect(const char *host, const char *port); +extern int xconnect(struct sockaddr_in *s_addr); +extern int bb_getport(char *port); +extern void bb_lookup_host(struct sockaddr_in *s_in, char *host, char *port); //#warning wrap this? char *dirname (char *path); diff --git a/libbb/safe_write.c b/libbb/safe_write.c index dd35f35ae..0ac6c2d96 100644 --- a/libbb/safe_write.c +++ b/libbb/safe_write.c @@ -26,7 +26,7 @@ -ssize_t safe_write(int fd, void *buf, size_t count) +ssize_t safe_write(int fd, const void *buf, size_t count) { ssize_t n; diff --git a/libbb/xconnect.c b/libbb/xconnect.c index 2945d760f..27459791e 100644 --- a/libbb/xconnect.c +++ b/libbb/xconnect.c @@ -11,69 +11,57 @@ #include #include #include +#include #include +#include #include +#include #include "libbb.h" -int xconnect(const char *host, const char *port) +int bb_getport(char *port) { -#ifdef CONFIG_FEATURE_IPV6 - struct addrinfo hints; - struct addrinfo *res; - struct addrinfo *addr_info; - int error; - int s; - - memset(&hints, 0, sizeof(hints)); - /* set-up hints structure */ - hints.ai_family = PF_UNSPEC; - hints.ai_socktype = SOCK_STREAM; - error = getaddrinfo(host, port, &hints, &res); - if (error||!res) - bb_perror_msg_and_die(gai_strerror(error)); - addr_info=res; - while (res) { - s=socket(res->ai_family, res->ai_socktype, res->ai_protocol); - if (s<0) - { - error=s; - res=res->ai_next; - continue; - } - /* try to connect() to res->ai_addr */ - error = connect(s, res->ai_addr, res->ai_addrlen); - if (error >= 0) - break; - close(s); - res=res->ai_next; - } - freeaddrinfo(addr_info); - if (error < 0) - { - bb_perror_msg_and_die("Unable to connect to remote host (%s)", host); - } - return s; -#else - struct sockaddr_in s_addr; - int s = socket(AF_INET, SOCK_STREAM, 0); + int port_nr; + char *endptr; struct servent *tserv; - int port_nr=htons(atoi(port)); - struct hostent * he; - if (port_nr==0 && (tserv = getservbyname(port, "tcp")) != NULL) - port_nr = tserv->s_port; - - memset(&s_addr, 0, sizeof(struct sockaddr_in)); - s_addr.sin_family = AF_INET; - s_addr.sin_port = port_nr; - - he = xgethostbyname(host); - memcpy(&s_addr.sin_addr, he->h_addr, sizeof s_addr.sin_addr); - - if (connect(s, (struct sockaddr *)&s_addr, sizeof s_addr) < 0) + if (!port) { + return -1; + } + port_nr=strtol(port, &endptr, 10); + if (errno != 0 || *endptr!='\0' || endptr==port || port_nr < 1 || port_nr > 65536) { - bb_perror_msg_and_die("Unable to connect to remote host (%s)", host); + if (port_nr==0 && (tserv = getservbyname(port, "tcp")) != NULL) { + port_nr = tserv->s_port; + } else { + return -1; + } + } else { + port_nr = htons(port_nr); + } + return port_nr; +} + +void bb_lookup_host(struct sockaddr_in *s_in, char *host, char *port) +{ + struct hostent *he; + + memset(s_in, 0, sizeof(struct sockaddr_in)); + s_in->sin_family = AF_INET; + he = xgethostbyname(host); + memcpy(&(s_in->sin_addr), he->h_addr_list[0], he->h_length); + + if (port) { + s_in->sin_port=bb_getport(port); + } +} + +int xconnect(struct sockaddr_in *s_addr) +{ + int s = socket(AF_INET, SOCK_STREAM, 0); + if (connect(s, (struct sockaddr_in *)s_addr, sizeof(struct sockaddr_in)) < 0) + { + bb_perror_msg_and_die("Unable to connect to remote host (%s)", + inet_ntoa(s_addr->sin_addr)); } return s; -#endif } diff --git a/networking/telnet.c b/networking/telnet.c index ac6ec98de..92ddfaebf 100644 --- a/networking/telnet.c +++ b/networking/telnet.c @@ -573,6 +573,7 @@ extern int telnet_main(int argc, char** argv) char *host; char *port; int len; + struct sockaddr_in s_in; #ifdef USE_POLL struct pollfd ufds[2]; #else @@ -601,7 +602,8 @@ extern int telnet_main(int argc, char** argv) host = argv[1]; - G.netfd = xconnect(host, port); + bb_lookup_host(&s_in, host, port); + G.netfd = xconnect(&s_in); setsockopt(G.netfd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof one); diff --git a/networking/wget.c b/networking/wget.c index 597d61097..08026915e 100644 --- a/networking/wget.c +++ b/networking/wget.c @@ -40,7 +40,7 @@ struct host_info { }; static void parse_url(char *url, struct host_info *h); -static FILE *open_socket(char *host, int port); +static FILE *open_socket(struct sockaddr_in *s_in, int port); static char *gethdr(char *buf, size_t bufsiz, FILE *fp, int *istrunc); static int ftpcmd(char *s1, char *s2, FILE *fp, char *buf); @@ -155,6 +155,7 @@ int wget_main(int argc, char **argv) int extra_headers_left = sizeof(extra_headers); int which_long_opt = 0, option_index = -1; struct host_info server, target; + struct sockaddr_in s_in; FILE *sfp = NULL; /* socket to web/ftp server */ FILE *dfp = NULL; /* socket to ftp server (data) */ @@ -290,6 +291,15 @@ int wget_main(int argc, char **argv) do_continue = 0; } + /* We want to do exactly _one_ DNS lookup, since some + * sites (i.e. ftp.us.debian.org) use round-robin DNS + * and we want to connect to only one IP... */ + bb_lookup_host(&s_in, server.host, NULL); + if (quiet_flag==FALSE) { + fprintf(stdout, "Connecting to %s[%s]:%d\n", + server.host, inet_ntoa(s_in.sin_addr), server.port); + } + if (proxy || !target.is_ftp) { /* * HTTP session @@ -304,7 +314,7 @@ int wget_main(int argc, char **argv) * Open socket to http server */ if (sfp) fclose(sfp); - sfp = open_socket(server.host, server.port); + sfp = open_socket(&s_in, server.port); /* * Send HTTP request. @@ -416,7 +426,7 @@ read_response: if (! target.user) target.user = bb_xstrdup("anonymous:busybox@"); - sfp = open_socket(server.host, server.port); + sfp = open_socket(&s_in, server.port); if (ftpcmd(NULL, NULL, sfp, buf) != 220) close_delete_and_die("%s", buf+4); @@ -459,7 +469,7 @@ read_response: port = atoi(s+1); s = strrchr(buf, ','); port += atoi(s+1) * 256; - dfp = open_socket(server.host, port); + dfp = open_socket(&s_in, port); if (do_continue) { sprintf(buf, "REST %ld", beg_range); @@ -584,14 +594,16 @@ void parse_url(char *url, struct host_info *h) } -FILE *open_socket(char *host, int port) +FILE *open_socket(struct sockaddr_in *s_in, int port) { int fd; FILE *fp; - char port_str[10]; - snprintf(port_str, sizeof(port_str), "%d", port); - fd=xconnect(host, port_str); + if (port>0 && port < 65536) { + s_in->sin_port=htons(port); + } + + fd=xconnect(s_in); /* * Get the server onto a stdio stream. @@ -838,7 +850,7 @@ progressmeter(int flag) * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: wget.c,v 1.60 2003/09/15 08:33:37 andersen Exp $ + * $Id: wget.c,v 1.61 2003/10/31 09:31:43 andersen Exp $ */ diff --git a/util-linux/rdate.c b/util-linux/rdate.c index 8d156cc78..a822f42ff 100644 --- a/util-linux/rdate.c +++ b/util-linux/rdate.c @@ -47,17 +47,16 @@ static void socket_timeout(int sig) static time_t askremotedate(const char *host) { unsigned long int nett, localt; - const char *port="37"; + struct sockaddr_in addr s_in; int fd; - if (getservbyname("time", "tcp") != NULL) - port="time"; + bb_lookup_host(&s_in, host, "time"); /* Add a timeout for dead or non accessable servers */ alarm(10); signal(SIGALRM, socket_timeout); - fd = xconnect(host, port); + fd = xconnect(s_in); if (safe_read(fd, (void *)&nett, 4) != 4) /* read time from server */ bb_error_msg_and_die("%s did not send the complete time", host);