diff options
Diffstat (limited to 'lib/liblwres/context.c')
-rw-r--r-- | lib/liblwres/context.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/lib/liblwres/context.c b/lib/liblwres/context.c new file mode 100644 index 000000000..40f8f3e3d --- /dev/null +++ b/lib/liblwres/context.c @@ -0,0 +1,380 @@ +/* + * Copyright (C) 2000, 2001 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM + * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL + * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING + * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION + * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: context.c,v 1.1 2004/03/15 20:35:25 as Exp $ */ + +#include <config.h> + +#include <fcntl.h> +#include <limits.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +#include <lwres/lwres.h> +#include <lwres/net.h> +#include <lwres/platform.h> + +#ifdef LWRES_PLATFORM_NEEDSYSSELECTH +#include <sys/select.h> +#endif + +#include "context_p.h" +#include "assert_p.h" + +/* + * Some systems define the socket length argument as an int, some as size_t, + * some as socklen_t. The last is what the current POSIX standard mandates. + * This definition is here so it can be portable but easily changed if needed. + */ +#ifndef LWRES_SOCKADDR_LEN_T +#define LWRES_SOCKADDR_LEN_T unsigned int +#endif + +/* + * Make a socket nonblocking. + */ +#ifndef MAKE_NONBLOCKING +#define MAKE_NONBLOCKING(sd, retval) \ +do { \ + retval = fcntl(sd, F_GETFL, 0); \ + if (retval != -1) { \ + retval |= O_NONBLOCK; \ + retval = fcntl(sd, F_SETFL, retval); \ + } \ +} while (0) +#endif + +lwres_uint16_t lwres_udp_port = LWRES_UDP_PORT; +const char *lwres_resolv_conf = LWRES_RESOLV_CONF; + +static void * +lwres_malloc(void *, size_t); + +static void +lwres_free(void *, void *, size_t); + +static lwres_result_t +context_connect(lwres_context_t *); + +lwres_result_t +lwres_context_create(lwres_context_t **contextp, void *arg, + lwres_malloc_t malloc_function, + lwres_free_t free_function, + unsigned int flags) +{ + lwres_context_t *ctx; + + REQUIRE(contextp != NULL && *contextp == NULL); + UNUSED(flags); + + /* + * If we were not given anything special to use, use our own + * functions. These are just wrappers around malloc() and free(). + */ + if (malloc_function == NULL || free_function == NULL) { + REQUIRE(malloc_function == NULL); + REQUIRE(free_function == NULL); + malloc_function = lwres_malloc; + free_function = lwres_free; + } + + ctx = malloc_function(arg, sizeof(lwres_context_t)); + if (ctx == NULL) + return (LWRES_R_NOMEMORY); + + /* + * Set up the context. + */ + ctx->malloc = malloc_function; + ctx->free = free_function; + ctx->arg = arg; + ctx->sock = -1; + + ctx->timeout = LWRES_DEFAULT_TIMEOUT; + ctx->serial = time(NULL); /* XXXMLG or BEW */ + + /* + * Init resolv.conf bits. + */ + lwres_conf_init(ctx); + + *contextp = ctx; + return (LWRES_R_SUCCESS); +} + +void +lwres_context_destroy(lwres_context_t **contextp) { + lwres_context_t *ctx; + + REQUIRE(contextp != NULL && *contextp != NULL); + + ctx = *contextp; + *contextp = NULL; + + if (ctx->sock != -1) { + close(ctx->sock); + ctx->sock = -1; + } + + CTXFREE(ctx, sizeof(lwres_context_t)); +} + +lwres_uint32_t +lwres_context_nextserial(lwres_context_t *ctx) { + REQUIRE(ctx != NULL); + + return (ctx->serial++); +} + +void +lwres_context_initserial(lwres_context_t *ctx, lwres_uint32_t serial) { + REQUIRE(ctx != NULL); + + ctx->serial = serial; +} + +void +lwres_context_freemem(lwres_context_t *ctx, void *mem, size_t len) { + REQUIRE(mem != NULL); + REQUIRE(len != 0); + + CTXFREE(mem, len); +} + +void * +lwres_context_allocmem(lwres_context_t *ctx, size_t len) { + REQUIRE(len != 0); + + return (CTXMALLOC(len)); +} + +static void * +lwres_malloc(void *arg, size_t len) { + void *mem; + + UNUSED(arg); + + mem = malloc(len); + if (mem == NULL) + return (NULL); + + memset(mem, 0xe5, len); + + return (mem); +} + +static void +lwres_free(void *arg, void *mem, size_t len) { + UNUSED(arg); + + memset(mem, 0xa9, len); + free(mem); +} + +static lwres_result_t +context_connect(lwres_context_t *ctx) { + int s; + int ret; + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + struct sockaddr *sa; + LWRES_SOCKADDR_LEN_T salen; + int domain; + + if (ctx->confdata.lwnext != 0) { + memcpy(&ctx->address, &ctx->confdata.lwservers[0], + sizeof(lwres_addr_t)); + LWRES_LINK_INIT(&ctx->address, link); + } else { + /* The default is the IPv4 loopback address 127.0.0.1. */ + memset(&ctx->address, 0, sizeof(ctx->address)); + ctx->address.family = LWRES_ADDRTYPE_V4; + ctx->address.length = 4; + ctx->address.address[0] = 127; + ctx->address.address[1] = 0; + ctx->address.address[2] = 0; + ctx->address.address[3] = 1; + } + + if (ctx->address.family == LWRES_ADDRTYPE_V4) { + memcpy(&sin.sin_addr, ctx->address.address, + sizeof(sin.sin_addr)); + sin.sin_port = htons(lwres_udp_port); + sin.sin_family = AF_INET; + sa = (struct sockaddr *)&sin; + salen = sizeof(sin); + domain = PF_INET; + } else if (ctx->address.family == LWRES_ADDRTYPE_V6) { + memcpy(&sin6.sin6_addr, ctx->address.address, + sizeof(sin6.sin6_addr)); + sin6.sin6_port = htons(lwres_udp_port); + sin6.sin6_family = AF_INET6; + sa = (struct sockaddr *)&sin6; + salen = sizeof(sin6); + domain = PF_INET6; + } else + return (LWRES_R_IOERROR); + + s = socket(domain, SOCK_DGRAM, IPPROTO_UDP); + if (s < 0) + return (LWRES_R_IOERROR); + + ret = connect(s, sa, salen); + if (ret != 0) { + close(s); + return (LWRES_R_IOERROR); + } + + MAKE_NONBLOCKING(s, ret); + if (ret < 0) + return (LWRES_R_IOERROR); + + ctx->sock = s; + + return (LWRES_R_SUCCESS); +} + +int +lwres_context_getsocket(lwres_context_t *ctx) { + return (ctx->sock); +} + +lwres_result_t +lwres_context_send(lwres_context_t *ctx, + void *sendbase, int sendlen) { + int ret; + lwres_result_t lwresult; + + if (ctx->sock == -1) { + lwresult = context_connect(ctx); + if (lwresult != LWRES_R_SUCCESS) + return (lwresult); + } + + ret = sendto(ctx->sock, sendbase, sendlen, 0, NULL, 0); + if (ret < 0) + return (LWRES_R_IOERROR); + if (ret != sendlen) + return (LWRES_R_IOERROR); + + return (LWRES_R_SUCCESS); +} + +lwres_result_t +lwres_context_recv(lwres_context_t *ctx, + void *recvbase, int recvlen, + int *recvd_len) +{ + LWRES_SOCKADDR_LEN_T fromlen; + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + struct sockaddr *sa; + int ret; + + if (ctx->address.family == LWRES_ADDRTYPE_V4) { + sa = (struct sockaddr *)&sin; + fromlen = sizeof(sin); + } else { + sa = (struct sockaddr *)&sin6; + fromlen = sizeof(sin6); + } + + /* + * The address of fromlen is cast to void * to shut up compiler + * warnings, namely on systems that have the sixth parameter + * prototyped as a signed int when LWRES_SOCKADDR_LEN_T is + * defined as unsigned. + */ + ret = recvfrom(ctx->sock, recvbase, recvlen, 0, sa, (void *)&fromlen); + + if (ret < 0) + return (LWRES_R_IOERROR); + + if (ret == recvlen) + return (LWRES_R_TOOLARGE); + + /* + * If we got something other than what we expect, have the caller + * wait for another packet. This can happen if an old result + * comes in, or if someone is sending us random stuff. + */ + if (ctx->address.family == LWRES_ADDRTYPE_V4) { + if (fromlen != sizeof(sin) + || memcmp(&sin.sin_addr, ctx->address.address, + sizeof(sin.sin_addr)) != 0 + || sin.sin_port != htons(lwres_udp_port)) + return (LWRES_R_RETRY); + } else { + if (fromlen != sizeof(sin6) + || memcmp(&sin6.sin6_addr, ctx->address.address, + sizeof(sin6.sin6_addr)) != 0 + || sin6.sin6_port != htons(lwres_udp_port)) + return (LWRES_R_RETRY); + } + + if (recvd_len != NULL) + *recvd_len = ret; + + return (LWRES_R_SUCCESS); +} + +lwres_result_t +lwres_context_sendrecv(lwres_context_t *ctx, + void *sendbase, int sendlen, + void *recvbase, int recvlen, + int *recvd_len) +{ + lwres_result_t result; + int ret2; + fd_set readfds; + struct timeval timeout; + + /* + * Type of tv_sec is long, so make sure the unsigned long timeout + * does not overflow it. + */ + if (ctx->timeout <= LONG_MAX) + timeout.tv_sec = (long)ctx->timeout; + else + timeout.tv_sec = LONG_MAX; + + timeout.tv_usec = 0; + + result = lwres_context_send(ctx, sendbase, sendlen); + if (result != LWRES_R_SUCCESS) + return (result); + again: + FD_ZERO(&readfds); + FD_SET(ctx->sock, &readfds); + ret2 = select(ctx->sock + 1, &readfds, NULL, NULL, &timeout); + + /* + * What happened with select? + */ + if (ret2 < 0) + return (LWRES_R_IOERROR); + if (ret2 == 0) + return (LWRES_R_TIMEOUT); + + result = lwres_context_recv(ctx, recvbase, recvlen, recvd_len); + if (result == LWRES_R_RETRY) + goto again; + + return (result); +} |