From a4dad7d5bf799c40d33e0db21414e0af1ee2647a Mon Sep 17 00:00:00 2001 From: Jo-Philipp Wich Date: Fri, 17 May 2024 15:25:45 +0200 Subject: [PATCH] socket: implement recvmsg(), sendmsg() and cmsg support Implement socket.recvmsg(), socket.sendmsg() and support for encoding and decoding well known control message types. Signed-off-by: Jo-Philipp Wich --- lib/socket.c | 992 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 990 insertions(+), 2 deletions(-) diff --git a/lib/socket.c b/lib/socket.c index e1489a36..dce80f30 100644 --- a/lib/socket.c +++ b/lib/socket.c @@ -58,6 +58,7 @@ #include #include #include +#include #include #include #include @@ -69,12 +70,22 @@ #include #include #include +#include +#include #include "ucode/module.h" #include "ucode/platform.h" #if defined(__linux__) # include + +# ifndef SO_TIMESTAMP_OLD +# define SO_TIMESTAMP_OLD SO_TIMESTAMP +# endif + +# ifndef SO_TIMESTAMPNS_OLD +# define SO_TIMESTAMPNS_OLD SO_TIMESTAMP +# endif #endif #if defined(__APPLE__) @@ -252,8 +263,14 @@ strbuf_size(uc_stringbuf_t *sb) static uc_value_t * strbuf_finish(uc_stringbuf_t **sb, size_t final_size) { - uc_string_t *us = (uc_string_t *)(*sb)->buf; - size_t buffer_size = strbuf_size(*sb); + size_t buffer_size; + uc_string_t *us; + + if (!sb || !*sb) + return NULL; + + buffer_size = strbuf_size(*sb); + us = (uc_string_t *)(*sb)->buf; if (final_size > buffer_size) final_size = buffer_size; @@ -445,6 +462,22 @@ parse_integer(char *s, size_t len) } } +static uint64_t +parse_unsigned(char *s, size_t len) +{ + union { uint8_t u8; uint16_t u16; uint32_t u32; uint64_t u64; } v; + + memcpy(&v, s, len < sizeof(v) ? len : sizeof(v)); + + switch (len) { + case 1: return v.u8; + case 2: return v.u16; + case 4: return v.u32; + case 8: return v.u64; + default: return 0; + } +} + static bool parse_addr(char *addr, struct sockaddr_storage *ss) { @@ -904,6 +937,12 @@ typedef struct { struct_t *ctype; } sockopt_t; +typedef struct { + int level; + int type; + struct_t *ctype; +} cmsgtype_t; + #define STRUCT_MEMBER_NP(struct_name, member_name, data_type) \ { #member_name, data_type, \ { .offset = offsetof(struct struct_name, member_name) }, \ @@ -1047,6 +1086,79 @@ static struct_t st_in6_pktinfo = { } }; +struct ipv6_recv_error_local { + struct { + uint32_t ee_errno; + uint8_t ee_origin; + uint8_t ee_type; + uint8_t ee_code; + uint8_t ee_pad; + uint32_t ee_info; + union { + uint32_t ee_data; + struct { + uint16_t ee_len; + uint8_t ee_flags; + uint8_t ee_reserved; + } ee_rfc4884; + } u; + } ee; + struct sockaddr_in6 offender; +}; + +static uc_value_t * +offender_to_uv(void *st) +{ + struct ipv6_recv_error_local *e = st; + uc_value_t *addr = ucv_object_new(NULL); + + if (sockaddr_to_uv((struct sockaddr_storage *)&e->offender, addr)) + return addr; + + ucv_put(addr); + + return NULL; +} + +static struct_t st_ip_recv_error = { + .size = sizeof(struct ipv6_recv_error_local), + .members = (member_t []){ + STRUCT_MEMBER(ipv6_recv_error_local, ee.ee, errno, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.ee, origin, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.ee, type, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.ee, code, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.ee, info, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.u.ee, data, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.u.ee_rfc4884.ee, len, DT_UNSIGNED), + STRUCT_MEMBER(ipv6_recv_error_local, ee.u.ee_rfc4884.ee, flags, DT_UNSIGNED), + STRUCT_MEMBER_CB(offender, NULL, offender_to_uv), + { 0 } + } +}; + +static uc_value_t * +ip6m_addr_to_uv(void *st) +{ + struct ip6_mtuinfo *mi = st; + uc_value_t *addr = ucv_object_new(NULL); + + if (sockaddr_to_uv((struct sockaddr_storage *)&mi->ip6m_addr, addr)) + return addr; + + ucv_put(addr); + + return NULL; +} + +static struct_t st_ip6_mtuinfo = { + .size = sizeof(struct ip6_mtuinfo), + .members = (member_t []){ + STRUCT_MEMBER_CB(addr, NULL, ip6m_addr_to_uv), + STRUCT_MEMBER(ip6_mtuinfo, ip6m, mtu, DT_UNSIGNED), + { 0 } + } +}; + static struct_t st_ip_msfilter = { .size = sizeof(struct ip_msfilter), .members = (member_t []){ @@ -1270,6 +1382,20 @@ static struct_t st_tpacket_stats = { } }; +static struct_t st_tpacket_auxdata = { + .size = sizeof(struct tpacket_auxdata), + .members = (member_t []){ + STRUCT_MEMBER(tpacket_auxdata, tp, status, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, len, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, snaplen, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, mac, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, net, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, vlan_tci, DT_UNSIGNED), + STRUCT_MEMBER(tpacket_auxdata, tp, vlan_tpid, DT_UNSIGNED), + { 0 } + } +}; + static struct_t st_fanout_args = { .size = sizeof(struct fanout_args), .members = (member_t []){ @@ -1279,6 +1405,58 @@ static struct_t st_fanout_args = { { 0 } } }; + +struct timeval_old_local { + long tv_sec; +#if defined(__sparc__) && defined(__arch64__) + int tv_usec; +#else + long tv_usec; +#endif +}; + +static struct_t st_timeval_old = { + .size = sizeof(struct timeval_old_local), + .members = (member_t []){ + STRUCT_MEMBER(timeval_old_local, tv, sec, DT_SIGNED), + STRUCT_MEMBER(timeval_old_local, tv, usec, DT_SIGNED), + { 0 } + } +}; + +# ifdef SO_TIMESTAMP_NEW +struct timeval_new_local { int64_t tv_sec; int64_t tv_usec; }; +static struct_t st_timeval_new = { + .size = sizeof(struct timeval_old_local), + .members = (member_t []){ + STRUCT_MEMBER(timeval_new_local, tv, sec, DT_SIGNED), + STRUCT_MEMBER(timeval_new_local, tv, usec, DT_SIGNED), + { 0 } + } +}; +# endif + +struct timespec_old_local { long tv_sec; long tv_nsec; }; +static struct_t st_timespec_old = { + .size = sizeof(struct timespec_old_local), + .members = (member_t []){ + STRUCT_MEMBER(timespec_old_local, tv, sec, DT_SIGNED), + STRUCT_MEMBER(timespec_old_local, tv, nsec, DT_SIGNED), + { 0 } + } +}; + +# ifdef SO_TIMESTAMPNS_NEW +struct timespec_new_local { long long tv_sec; long long tv_nsec; }; +static struct_t st_timespec_new = { + .size = sizeof(struct timespec_new_local), + .members = (member_t []){ + STRUCT_MEMBER(timespec_new_local, tv, sec, DT_SIGNED), + STRUCT_MEMBER(timespec_new_local, tv, nsec, DT_SIGNED), + { 0 } + } +}; +# endif #endif #define SV_VOID (struct_t *)0 @@ -1288,6 +1466,13 @@ static struct_t st_fanout_args = { #define SV_STRING (struct_t *)4 #define SV_IFNAME (struct_t *)5 +#define CV_INT (struct_t *)0 +#define CV_UINT (struct_t *)1 +#define CV_BE32 (struct_t *)2 +#define CV_STRING (struct_t *)3 +#define CV_SOCKADDR (struct_t *)4 +#define CV_FDS (struct_t *)5 + static sockopt_t sockopts[] = { { SOL_SOCKET, SO_ACCEPTCONN, SV_BOOL }, { SOL_SOCKET, SO_BROADCAST, SV_BOOL }, @@ -1452,6 +1637,52 @@ static sockopt_t sockopts[] = { #endif }; +static cmsgtype_t cmsgtypes[] = { +#if defined(__linux__) + { SOL_PACKET, PACKET_AUXDATA, &st_tpacket_auxdata }, + + { SOL_SOCKET, SO_TIMESTAMP_OLD, &st_timeval_old }, +# ifdef SO_TIMESTAMP_NEW + { SOL_SOCKET, SO_TIMESTAMP_NEW, &st_timeval_new }, +# endif + { SOL_SOCKET, SO_TIMESTAMPNS_OLD, &st_timespec_old }, +# ifdef SO_TIMESTAMPNS_NEW + { SOL_SOCKET, SO_TIMESTAMPNS_NEW, &st_timespec_new }, +# endif + + { SOL_SOCKET, SCM_CREDENTIALS, &st_ucred }, + { SOL_SOCKET, SCM_RIGHTS, CV_FDS }, +#endif + + { IPPROTO_IP, IP_RECVOPTS, SV_STRING }, + { IPPROTO_IP, IP_RETOPTS, SV_STRING }, + { IPPROTO_IP, IP_TOS, CV_INT }, + { IPPROTO_IP, IP_TTL, CV_INT }, +#if defined(__linux__) + { IPPROTO_IP, IP_CHECKSUM, CV_UINT }, + { IPPROTO_IP, IP_ORIGDSTADDR, CV_SOCKADDR }, + { IPPROTO_IP, IP_RECVERR, &st_ip_recv_error }, + { IPPROTO_IP, IP_RECVFRAGSIZE, CV_INT }, +#endif + + { IPPROTO_IPV6, IPV6_TCLASS, CV_INT }, + { IPPROTO_IPV6, IPV6_FLOWINFO, CV_BE32 }, +#if defined(__linux__) + { IPPROTO_IPV6, IPV6_DSTOPTS, CV_STRING }, + { IPPROTO_IPV6, IPV6_HOPLIMIT, CV_INT }, + { IPPROTO_IPV6, IPV6_HOPOPTS, CV_STRING }, + { IPPROTO_IPV6, IPV6_ORIGDSTADDR, CV_SOCKADDR }, + { IPPROTO_IPV6, IPV6_PATHMTU, &st_ip6_mtuinfo }, + { IPPROTO_IPV6, IPV6_PKTINFO, &st_in6_pktinfo }, + { IPPROTO_IPV6, IPV6_RECVERR, &st_ip_recv_error }, + { IPPROTO_IPV6, IPV6_RECVFRAGSIZE, CV_INT }, + { IPPROTO_IPV6, IPV6_RTHDR, CV_STRING }, + + { IPPROTO_TCP, TCP_CM_INQ, CV_INT }, + { IPPROTO_UDP, UDP_GRO, CV_INT }, +#endif +}; + static char * uv_to_struct(uc_value_t *uv, struct_t *spec) @@ -3073,6 +3304,758 @@ uc_socket_inst_recv(uc_vm_t *vm, size_t nargs) ok_return(strbuf_finish(&buf, ret)); } +uc_declare_vector(strbuf_array_t, uc_stringbuf_t *); + +#if defined(__linux__) +static void optmem_max(size_t *sz) { + char buf[sizeof("18446744073709551615")] = { 0 }; + int fd, rv; + + fd = open("/proc/sys/net/core/optmem_max", O_RDONLY); + + if (fd >= 0) { + if (read(fd, buf, sizeof(buf) - 1) > 0) { + rv = strtol(buf, NULL, 10); + + if (rv > 0 && (size_t)rv < *sz) + *sz = rv; + } + + if (fd > 2) + close(fd); + } +} +#else +# define optmem_max(x) +#endif + + +/** + * Represents a single control (ancillary data) message returned + * in the *ancillary* array by {@link module:socket.socket#recvmsg|`recvmsg()`}. + * + * @typedef {Object} module:socket.socket.ControlMessage + * @property {number} level + * The message socket level (`cmsg_level`), e.g. `SOL_SOCKET`. + * + * @property {number} type + * The protocol specific message type (`cmsg_type`), e.g. `SCM_RIGHTS`. + * + * @property {*} data + * The payload of the control message. If the control message type is known by + * the socket module, it is represented as a mixed value (array, object, number, + * etc.) with structure specific to the control message type. If the control + * message cannot be decoded, *data* is set to a string value containing the raw + * payload. + */ +static uc_value_t * +decode_cmsg(uc_vm_t *vm, struct cmsghdr *cmsg) +{ + char *s = (char *)CMSG_DATA(cmsg); + size_t sz = cmsg->cmsg_len - sizeof(*cmsg); + struct sockaddr_storage *ss; + uc_value_t *fdarr; + struct stat st; + int *fds; + + for (size_t i = 0; i < ARRAY_SIZE(cmsgtypes); i++) { + + if (cmsgtypes[i].level != cmsg->cmsg_level) + continue; + + if (cmsgtypes[i].type != cmsg->cmsg_type) + continue; + + switch ((uintptr_t)cmsgtypes[i].ctype) { + case (uintptr_t)CV_INT: + return ucv_int64_new(parse_integer(s, sz)); + + case (uintptr_t)CV_UINT: + case (uintptr_t)CV_BE32: + return ucv_uint64_new(parse_unsigned(s, sz)); + + case (uintptr_t)CV_SOCKADDR: + ss = (struct sockaddr_storage *)s; + + if ((sz >= sizeof(struct sockaddr_in) && + ss->ss_family == AF_INET) || + (sz >= sizeof(struct sockaddr_in6) && + ss->ss_family == AF_INET6)) + { + uc_value_t *addr = ucv_object_new(vm); + + if (sockaddr_to_uv(ss, addr)) + return addr; + + ucv_put(addr); + } + + return NULL; + + case (uintptr_t)CV_FDS: + fdarr = ucv_array_new_length(vm, sz / sizeof(int)); + fds = (int *)s; + + for (size_t i = 0; i < sz / sizeof(int); i++) { + if (fstat(fds[i], &st) == 0) { + uc_resource_type_t *t; + + if (S_ISSOCK(st.st_mode)) { + t = ucv_resource_type_lookup(vm, "socket"); + + ucv_array_push(fdarr, + ucv_resource_new(t, (void *)(intptr_t)fds[i])); + + continue; + } + else if (S_ISDIR(st.st_mode)) { + t = ucv_resource_type_lookup(vm, "fs.dir"); + + if (t) { + DIR *d = fdopendir(fds[i]); + + if (d) { + ucv_array_push(fdarr, ucv_resource_new(t, d)); + continue; + } + } + } + else { + t = ucv_resource_type_lookup(vm, "fs.file"); + + if (t) { + int n = fcntl(fds[i], F_GETFL); + const char *mode; + + if (n <= 0 || (n & O_ACCMODE) == O_RDONLY) + mode = "r"; + else if ((n & O_ACCMODE) == O_WRONLY) + mode = (n & O_APPEND) ? "a" : "w"; + else + mode = (n & O_APPEND) ? "a+" : "w+"; + + FILE *f = fdopen(fds[i], mode); + + if (f) { + ucv_array_push(fdarr, uc_resource_new(t, f)); + continue; + } + } + } + } + + ucv_array_push(fdarr, ucv_int64_new(fds[i])); + } + + return fdarr; + + case (uintptr_t)CV_STRING: + break; + + default: + if (sz >= cmsgtypes[i].ctype->size) + return struct_to_uv(s, cmsgtypes[i].ctype); + } + + break; + } + + return ucv_string_new_length(s, sz); +} + +static size_t +estimate_cmsg_size(uc_value_t *uv) +{ + int cmsg_level = ucv_to_integer(ucv_object_get(uv, "level", NULL)); + int cmsg_type = ucv_to_integer(ucv_object_get(uv, "type", NULL)); + uc_value_t *val = ucv_object_get(uv, "data", NULL); + + for (size_t i = 0; i < ARRAY_SIZE(cmsgtypes); i++) { + if (cmsgtypes[i].level != cmsg_level) + continue; + + if (cmsgtypes[i].type != cmsg_type) + continue; + + switch ((uintptr_t)cmsgtypes[i].ctype) { + case (uintptr_t)CV_INT: return sizeof(int); + case (uintptr_t)CV_UINT: return sizeof(unsigned int); + case (uintptr_t)CV_BE32: return sizeof(uint32_t); + case (uintptr_t)CV_SOCKADDR: return sizeof(struct sockaddr_storage); + case (uintptr_t)CV_FDS: return ucv_array_length(val) * sizeof(int); + case (uintptr_t)CV_STRING: return ucv_string_length(val); + default: return cmsgtypes[i].ctype->size; + } + } + + switch (ucv_type(val)) { + case UC_BOOLEAN: return sizeof(unsigned int); + case UC_INTEGER: return sizeof(int); + case UC_STRING: return ucv_string_length(val); + default: return 0; + } +} + +static bool +encode_cmsg(uc_vm_t *vm, uc_value_t *uv, struct cmsghdr *cmsg) +{ + struct { int *entries; size_t count; } fds = { 0 }; + void *dataptr = NULL; + socklen_t datasz = 0; + char *st = NULL; + size_t i; + union { + int i; + unsigned int u; + uint32_t u32; + struct sockaddr_storage ss; + } val; + + cmsg->cmsg_level = ucv_to_integer(ucv_object_get(uv, "level", NULL)); + cmsg->cmsg_type = ucv_to_integer(ucv_object_get(uv, "type", NULL)); + + uc_value_t *data = ucv_object_get(uv, "data", NULL); + + for (i = 0; i < ARRAY_SIZE(cmsgtypes); i++) { + if (cmsgtypes[i].level != cmsg->cmsg_level) + continue; + + if (cmsgtypes[i].type != cmsg->cmsg_type) + continue; + + switch ((uintptr_t)cmsgtypes[i].ctype) { + case (uintptr_t)CV_INT: + val.i = ucv_to_integer(data); + datasz = sizeof(val.i); + dataptr = &val; + break; + + case (uintptr_t)CV_UINT: + val.u = ucv_to_unsigned(data); + datasz = sizeof(val.u); + dataptr = &val; + break; + + case (uintptr_t)CV_BE32: + val.u32 = ucv_to_unsigned(data); + datasz = sizeof(val.u32); + dataptr = &val; + break; + + case (uintptr_t)CV_SOCKADDR: + if (uv_to_sockaddr(data, &val.ss, &datasz)) + dataptr = &val; + else + datasz = 0, dataptr = NULL; + break; + + case (uintptr_t)CV_FDS: + if (ucv_type(data) == UC_ARRAY) { + for (size_t i = 0; i < ucv_array_length(data); i++) { + int fd; + + if (uv_to_fileno(vm, ucv_array_get(data, i), &fd)) + uc_vector_push(&fds, fd); + } + } + + datasz = sizeof(fds.entries[0]) * fds.count; + dataptr = fds.entries; + break; + + case (uintptr_t)CV_STRING: + datasz = ucv_string_length(data); + dataptr = ucv_string_get(data); + break; + + default: + st = uv_to_struct(data, cmsgtypes[i].ctype); + datasz = st ? cmsgtypes[i].ctype->size : 0; + dataptr = st; + break; + } + + break; + } + + /* we don't know this kind of control message, guess encoding */ + if (i == ARRAY_SIZE(cmsgtypes)) { + switch (ucv_type(data)) { + /* treat boolean as int with values 1 or 0 */ + case UC_BOOLEAN: + val.u = ucv_boolean_get(data); + dataptr = &val; + datasz = sizeof(val.u); + break; + + /* treat integers as int */ + case UC_INTEGER: + if (ucv_is_u64(data)) { + val.u = ucv_uint64_get(data); + datasz = sizeof(val.u); + } + else { + val.i = ucv_int64_get(data); + datasz = sizeof(val.i); + } + + dataptr = &val; + break; + + /* pass strings as-is */ + case UC_STRING: + dataptr = ucv_string_get(data); + datasz = ucv_string_length(data); + break; + + default: + break; + } + } + + cmsg->cmsg_len = CMSG_LEN(datasz); + + if (dataptr) + memcpy(CMSG_DATA(cmsg), dataptr, datasz); + + uc_vector_clear(&fds); + free(st); + + return true; +} + +/** + * Sends a message through the socket. + * + * Sends a message through the socket handle, supporting complex message + * structures including multiple data buffers and ancillary data. This function + * allows for precise control over the message content and delivery behavior. + * + * Returns the number of sent bytes. + * + * Returns `null` if an error occurred. + * + * @function module:socket.socket#sendmsg + * + * @param {*} [data] + * The data to be sent. If a string is provided, it is sent as is. If an array + * is specified, each item is sent as a separate `struct iovec`. Non-string + * values are implicitly converted to a string and sent. If omitted, only + * ancillary data and address are considered. + * + * @param {module:socket.socket.ControlMessage[]|string} [ancillaryData] + * Optional ancillary data to be sent. If an array is provided, each element is + * converted to a control message. If a string is provided, it is sent as-is + * without further interpretation. Refer to + * {@link module:socket.socket#recvmsg|`recvmsg()`} and + * {@link module:socket.socket.ControlMessage|ControlMessage} for details. + * + * @param {module:socket.socket.SocketAddress} [address] + * The destination address for the message. If provided, it sets or overrides + * the packet destination address. + * + * @param {number} [flags] + * Optional flags to modify the behavior of the send operation. This should be a + * bitwise OR-ed combination of `MSG_*` flag values. + * + * @returns {?number} + * Returns the number of bytes sent on success, or `null` if an error occurred. + * + * @example + * // Send file descriptors over domain socket + * const f1 = fs.open("example.txt", "w"); + * const f2 = fs.popen("date +%s", "r"); + * const sk = socket.connect({ family: socket.AF_UNIX, path: "/tmp/socket" }); + + * sk.sendmsg("Hi there, here's some descriptors!", [ + * { level: socket.SOL_SOCKET, type: socket.SCM_RIGHTS, data: [ f1, f2 ] } + * ]); + * + * // Send multiple values in one datagram + * sk.sendmsg([ "This", "is", "one", "message" ]); + */ +static uc_value_t * +uc_socket_inst_sendmsg(uc_vm_t *vm, size_t nargs) +{ + uc_value_t *data, *ancdata, *addr, *flags; + struct sockaddr_storage ss = { 0 }; + strbuf_array_t sbarr = { 0 }; + struct msghdr msg = { 0 }; + struct iovec vec = { 0 }; + int flagval, sockfd; + socklen_t slen; + ssize_t ret; + + args_get(vm, nargs, &sockfd, + "data", UC_NULL, true, &data, + "ancillary data", UC_NULL, true, &ancdata, + "address", UC_OBJECT, true, &addr, + "flags", UC_INTEGER, true, &flags); + + flagval = flags ? ucv_int64_get(flags) : 0; + + /* treat string ancdata arguemnt as raw controldata buffer */ + if (ucv_type(ancdata) == UC_STRING) { + msg.msg_control = ucv_string_get(ancdata); + msg.msg_controllen = ucv_string_length(ancdata); + } + /* encode ancdata passed as array */ + else if (ucv_type(ancdata) == UC_ARRAY) { + msg.msg_controllen = 0; + + for (size_t i = 0; i < ucv_array_length(ancdata); i++) { + size_t sz = estimate_cmsg_size(ucv_array_get(ancdata, i)); + + if (sz > 0) + msg.msg_controllen += CMSG_SPACE(sz); + } + + if (msg.msg_controllen > 0) { + msg.msg_control = xalloc(msg.msg_controllen); + + struct cmsghdr *cmsg = NULL; + + for (size_t i = 0; i < ucv_array_length(ancdata); i++) { + cmsg = i ? CMSG_NXTHDR(&msg, cmsg) : CMSG_FIRSTHDR(&msg); + + if (!cmsg) { + free(msg.msg_control); + err_return(ENOBUFS, "Not enough CMSG buffer space"); + } + + if (!encode_cmsg(vm, ucv_array_get(ancdata, i), cmsg)) { + free(msg.msg_control); + return NULL; + } + } + + msg.msg_controllen = (cmsg != NULL) + ? (char *)cmsg - (char *)msg.msg_control + CMSG_SPACE(cmsg->cmsg_len) + : 0; + } + } + else if (ancdata) { + err_return(EINVAL, "Ancillary data must be string or array value"); + } + + /* prepare iov array */ + if (ucv_type(data) == UC_ARRAY) { + msg.msg_iovlen = ucv_array_length(data); + msg.msg_iov = (msg.msg_iovlen > 1) + ? xalloc(sizeof(vec) * msg.msg_iovlen) : &vec; + + for (size_t i = 0; i < (size_t)msg.msg_iovlen; i++) { + uc_value_t *item = ucv_array_get(data, i); + + if (ucv_type(item) == UC_STRING) { + msg.msg_iov[i].iov_base = _ucv_string_get(&((uc_array_t *)data)->entries[i]); + msg.msg_iov[i].iov_len = ucv_string_length(item); + } + else if (item) { + struct printbuf *pb = xprintbuf_new(); + uc_vector_push(&sbarr, pb); + ucv_to_stringbuf(vm, pb, item, false); + msg.msg_iov[i].iov_base = pb->buf; + msg.msg_iov[i].iov_len = pb->bpos; + } + } + } + else if (ucv_type(data) == UC_STRING) { + msg.msg_iovlen = 1; + msg.msg_iov = &vec; + vec.iov_base = ucv_string_get(data); + vec.iov_len = ucv_string_length(data); + } + else if (data) { + struct printbuf *pb = xprintbuf_new(); + uc_vector_push(&sbarr, pb); + ucv_to_stringbuf(vm, pb, data, false); + msg.msg_iovlen = 1; + msg.msg_iov = &vec; + vec.iov_base = pb->buf; + vec.iov_len = pb->bpos; + } + + /* prepare address */ + if (addr && uv_to_sockaddr(addr, &ss, &slen)) { + msg.msg_name = &ss; + msg.msg_namelen = slen; + } + + /* now send actual data */ + do { + ret = sendmsg(sockfd, &msg, flagval); + } while (ret == -1 && errno == EINTR); + + while (sbarr.count > 0) + printbuf_free(sbarr.entries[--sbarr.count]); + + uc_vector_clear(&sbarr); + + if (msg.msg_iov != &vec) + free(msg.msg_iov); + + free(msg.msg_control); + + if (ret == -1) + err_return(errno, "sendmsg()"); + + ok_return(ucv_int64_new(ret)); +} + + + +/** + * Represents a message object returned by + * {@link module:socket.socket#recvmsg|`recvmsg()`}. + * + * @typedef {Object} module:socket.socket.ReceivedMessage + * @property {number} flags + * Integer value containing bitwise OR-ed `MSG_*` result flags returned by the + * underlying receive call. + * + * @property {number} length + * Integer value containing the number of bytes returned by the `recvmsg()` + * syscall, which might be larger than the received data in case `MSG_TRUNC` + * was passed. + * + * @property {module:socket.socket.SocketAddress} address + * The address from which the message was received. + * + * @property {string[]|string} data + * An array of strings, each representing the received message data. + * Each string corresponds to one buffer size specified in the *sizes* argument. + * If a single receive size was passed instead of an array of sizes, *data* will + * hold a string containing the received data. + * + * @property {module:socket.socket.ControlMessage[]} [ancillary] + * An array of received control messages. Only included if a non-zero positive + * *ancillarySize* was passed to `recvmsg()`. + */ + +/** + * Receives a message from the socket. + * + * Receives a message from the socket handle, allowing for more complex data + * reception compared to `recv()`. This includes the ability to receive + * ancillary data (such as file descriptors, credentials, etc.), multiple + * message segments, and optional flags to modify the receive behavior. + * + * Returns an object containing the received message data, ancillary data, + * and the sender's address. + * + * Returns `null` if an error occurred during the receive operation. + * + * @function module:socket.socket#recvmsg + * + * @param {number[]|number} [sizes] + * Specifies the sizes of the buffers used for receiving the message. If an + * array of numbers is provided, each number determines the size of an + * individual buffer segment, creating multiple `struct iovec` for reception. + * If a single number is provided, a single buffer of that size is used. + * + * @param {number} [ancillarySize] + * The size allocated for the ancillary data buffer. If not provided, ancillary + * data is not processed. + * + * @param {number} [flags] + * Optional flags to modify the behavior of the receive operation. This should + * be a bitwise OR-ed combination of flag values. + * + * @returns {?module:socket.socket.ReceivedMessage} + * An object containing the received message data, ancillary data, + * and the sender's address. + * + * @example + * // Receive file descriptors over domain socket + * const sk = socket.listen({ family: socket.AF_UNIX, path: "/tmp/socket" }); + * sk.setopt(socket.SOL_SOCKET, socket.SO_PASSCRED, true); + * + * const msg = sk.recvmsg(1024, 1024); * + * for (let cmsg in msg.ancillary) + * if (cmsg.level == socket.SOL_SOCKET && cmsg.type == socket.SCM_RIGHTS) + * print(`Got some descriptors: ${cmsg.data}!\n`); + * + * // Receive message in segments of 10, 128 and 512 bytes + * const msg = sk.recvmsg([ 10, 128, 512 ]); + * print(`Message parts: ${msg.data[0]}, ${msg.data[1]}, ${msg.data[2]}\n`); + * + * // Peek buffer + * const msg = sk.recvmsg(0, 0, socket.MSG_PEEK|socket.MSG_TRUNC); + * print(`Received ${length(msg.data)} bytes, ${msg.length} bytes available\n`); + */ +static uc_value_t * +uc_socket_inst_recvmsg(uc_vm_t *vm, size_t nargs) +{ + uc_value_t *length, *anclength, *flags, *rv; + struct sockaddr_storage ss = { 0 }; + strbuf_array_t sbarr = { 0 }; + struct msghdr msg = { 0 }; + struct iovec vec = { 0 }; + int flagval, sockfd; + ssize_t ret; + + args_get(vm, nargs, &sockfd, + "length", UC_NULL, true, &length, + "ancillary length", UC_INTEGER, true, &anclength, + "flags", UC_INTEGER, true, &flags); + + flagval = flags ? ucv_int64_get(flags) : 0; + +#if defined(__linux__) + flagval |= MSG_CMSG_CLOEXEC; +#endif + + /* prepare ancillary data buffer */ + if (anclength) { + size_t sz = ucv_to_unsigned(anclength); + + if (errno != 0) + err_return(errno, "Invalid ancillary data length"); + + optmem_max(&sz); + + if (sz > 0) { + msg.msg_controllen = sz; + msg.msg_control = xalloc(sz); + } + } + + /* prepare iov array */ + if (ucv_type(length) == UC_ARRAY) { + msg.msg_iovlen = ucv_array_length(length); + msg.msg_iov = (msg.msg_iovlen > 1) + ? xalloc(sizeof(vec) * msg.msg_iovlen) : &vec; + + for (size_t i = 0; i < (size_t)msg.msg_iovlen; i++) { + size_t sz = ucv_to_unsigned(ucv_array_get(length, i)); + + if (errno != 0) { + while (sbarr.count > 0) + strbuf_free(sbarr.entries[--sbarr.count]); + + uc_vector_clear(&sbarr); + + if (msg.msg_iov != &vec) + free(msg.msg_iov); + + free(msg.msg_control); + + err_return(errno, "Invalid length value"); + } + + uc_vector_push(&sbarr, strbuf_alloc(sz)); + msg.msg_iov[i].iov_base = strbuf_data(sbarr.entries[i]); + msg.msg_iov[i].iov_len = sz; + } + } + else { + size_t sz = ucv_to_unsigned(length); + + if (errno != 0) { + free(msg.msg_control); + err_return(errno, "Invalid length value"); + } + + uc_vector_push(&sbarr, strbuf_alloc(sz)); + + msg.msg_iovlen = 1; + msg.msg_iov = &vec; + vec.iov_base = strbuf_data(sbarr.entries[0]); + vec.iov_len = sz; + } + + /* now receive actual data */ + msg.msg_name = &ss; + msg.msg_namelen = sizeof(ss); + + do { + ret = recvmsg(sockfd, &msg, flagval); + } while (ret == -1 && errno == EINTR); + + if (ret == -1) { + while (sbarr.count > 0) + strbuf_free(sbarr.entries[--sbarr.count]); + + uc_vector_clear(&sbarr); + + if (msg.msg_iov != &vec) + free(msg.msg_iov); + + free(msg.msg_control); + + err_return(errno, "recvmsg()"); + } + + rv = ucv_object_new(vm); + + ucv_object_add(rv, "flags", ucv_int64_new(msg.msg_flags)); + ucv_object_add(rv, "length", ucv_int64_new(ret)); + + if (msg.msg_namelen > 0) { + uc_value_t *addr = ucv_object_new(vm); + + if (sockaddr_to_uv(&ss, addr)) + ucv_object_add(rv, "address", addr); + else + ucv_put(addr); + } + + if (msg.msg_controllen > 0) { + uc_value_t *ancillary = ucv_array_new(vm); + + for (struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg); + cmsg != NULL; + cmsg = CMSG_NXTHDR(&msg, cmsg)) + { + uc_value_t *c = ucv_object_new(vm); + + ucv_object_add(c, "level", ucv_int64_new(cmsg->cmsg_level)); + ucv_object_add(c, "type", ucv_int64_new(cmsg->cmsg_type)); + ucv_object_add(c, "data", decode_cmsg(vm, cmsg)); + + ucv_array_push(ancillary, c); + } + + ucv_object_add(rv, "ancillary", ancillary); + } + + if (ret >= 0) { + if (ucv_type(length) == UC_ARRAY) { + uc_value_t *data = ucv_array_new_length(vm, msg.msg_iovlen); + + for (size_t i = 0; i < (size_t)msg.msg_iovlen; i++) { + size_t sz = ret; + + if (sz > msg.msg_iov[i].iov_len) + sz = msg.msg_iov[i].iov_len; + + ucv_array_push(data, strbuf_finish(&sbarr.entries[i], sz)); + ret -= sz; + } + + ucv_object_add(rv, "data", data); + } + else { + size_t sz = ret; + + if (sz > msg.msg_iov[0].iov_len) + sz = msg.msg_iov[0].iov_len; + + ucv_object_add(rv, "data", strbuf_finish(&sbarr.entries[0], sz)); + } + } + + uc_vector_clear(&sbarr); + + if (msg.msg_iov != &vec) + free(msg.msg_iov); + + free(msg.msg_control); + + ok_return(rv); +} + /** * Binds a socket to a specific address. * @@ -3599,7 +4582,9 @@ static const uc_function_list_t socket_fns[] = { { "listen", uc_socket_inst_listen }, { "accept", uc_socket_inst_accept }, { "send", uc_socket_inst_send }, + { "sendmsg", uc_socket_inst_sendmsg }, { "recv", uc_socket_inst_recv }, + { "recvmsg", uc_socket_inst_recvmsg }, { "setopt", uc_socket_inst_setopt }, { "getopt", uc_socket_inst_getopt }, { "fileno", uc_socket_inst_fileno }, @@ -3991,6 +4976,9 @@ void uc_module_init(uc_vm_t *vm, uc_value_t *scope) ADD_CONST(SO_RXQ_OVFL); ADD_CONST(SO_SNDBUFFORCE); ADD_CONST(SO_TIMESTAMPNS); + + ADD_CONST(SCM_CREDENTIALS); + ADD_CONST(SCM_RIGHTS); #endif /**