Magellan Linux

  • Back to homepage
    • /[magellan-source]/trunk/mkinitrd-magellan/busybox/libbb/udp_io.c

    Annotation of /trunk/mkinitrd-magellan/busybox/libbb/udp_io.c

    Parent Directory Parent Directory | Revision Log Revision Log

    Revision 816 - (hide annotations) (download)
    Fri Apr 24 18:33:46 2009 UTC (15 years, 1 month ago) by niro
    File MIME type: text/plain
    File size: 4694 byte(s) 
    -updated to busybox-1.13.4
    1 niro 816 /* vi: set sw=4 ts=4: */
    2     /*
    3     * Utility routines.
    4     *
    5     * Copyright (C) 2007 Denys Vlasenko
    6     *
    7     * Licensed under GPL version 2, see file LICENSE in this tarball for details.
    8     */
    9    
    10     #include "libbb.h"
    11    
    12     /*
    13     * This asks kernel to let us know dst addr/port of incoming packets
    14     * We don't check for errors here. Not supported == won't be used
    15     */
    16     void FAST_FUNC
    17     socket_want_pktinfo(int fd)
    18     {
    19     #ifdef IP_PKTINFO
    20     setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &const_int_1, sizeof(int));
    21     #endif
    22     #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
    23     setsockopt(fd, IPPROTO_IPV6, IPV6_PKTINFO, &const_int_1, sizeof(int));
    24     #endif
    25     }
    26    
    27    
    28     ssize_t FAST_FUNC
    29     send_to_from(int fd, void *buf, size_t len, int flags,
    30     const struct sockaddr *to,
    31     const struct sockaddr *from,
    32     socklen_t tolen)
    33     {
    34     #ifndef IP_PKTINFO
    35     return sendto(fd, buf, len, flags, to, tolen);
    36     #else
    37     struct iovec iov[1];
    38     struct msghdr msg;
    39     union {
    40     char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
    41     #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
    42     char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
    43     #endif
    44     } u;
    45     struct cmsghdr* cmsgptr;
    46    
    47     if (from->sa_family != AF_INET
    48     #if ENABLE_FEATURE_IPV6
    49     && from->sa_family != AF_INET6
    50     #endif
    51     ) {
    52     /* ANY local address */
    53     return sendto(fd, buf, len, flags, to, tolen);
    54     }
    55    
    56     /* man recvmsg and man cmsg is needed to make sense of code below */
    57    
    58     iov[0].iov_base = buf;
    59     iov[0].iov_len = len;
    60    
    61     memset(&u, 0, sizeof(u));
    62    
    63     memset(&msg, 0, sizeof(msg));
    64     msg.msg_name = (void *)(struct sockaddr *)to; /* or compiler will annoy us */
    65     msg.msg_namelen = tolen;
    66     msg.msg_iov = iov;
    67     msg.msg_iovlen = 1;
    68     msg.msg_control = &u;
    69     msg.msg_controllen = sizeof(u);
    70     msg.msg_flags = flags;
    71    
    72     cmsgptr = CMSG_FIRSTHDR(&msg);
    73     if (to->sa_family == AF_INET && from->sa_family == AF_INET) {
    74     struct in_pktinfo *pktptr;
    75     cmsgptr->cmsg_level = IPPROTO_IP;
    76     cmsgptr->cmsg_type = IP_PKTINFO;
    77     cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
    78     pktptr = (struct in_pktinfo *)(CMSG_DATA(cmsgptr));
    79     /* pktptr->ipi_ifindex = 0; -- already done by memset(cbuf...) */
    80     pktptr->ipi_spec_dst = ((struct sockaddr_in*)from)->sin_addr;
    81     }
    82     #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
    83     else if (to->sa_family == AF_INET6 && from->sa_family == AF_INET6) {
    84     struct in6_pktinfo *pktptr;
    85     cmsgptr->cmsg_level = IPPROTO_IPV6;
    86     cmsgptr->cmsg_type = IPV6_PKTINFO;
    87     cmsgptr->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
    88     pktptr = (struct in6_pktinfo *)(CMSG_DATA(cmsgptr));
    89     /* pktptr->ipi6_ifindex = 0; -- already done by memset(cbuf...) */
    90     pktptr->ipi6_addr = ((struct sockaddr_in6*)from)->sin6_addr;
    91     }
    92     #endif
    93     msg.msg_controllen = cmsgptr->cmsg_len;
    94    
    95     return sendmsg(fd, &msg, flags);
    96     #endif
    97     }
    98    
    99     /* NB: this will never set port# in 'to'!
    100     * _Only_ IP/IPv6 address part of 'to' is _maybe_ modified.
    101     * Typical usage is to preinit 'to' with "default" value
    102     * before calling recv_from_to(). */
    103     ssize_t FAST_FUNC
    104     recv_from_to(int fd, void *buf, size_t len, int flags,
    105     struct sockaddr *from, struct sockaddr *to,
    106     socklen_t sa_size)
    107     {
    108     #ifndef IP_PKTINFO
    109     return recvfrom(fd, buf, len, flags, from, &sa_size);
    110     #else
    111     /* man recvmsg and man cmsg is needed to make sense of code below */
    112     struct iovec iov[1];
    113     union {
    114     char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))];
    115     #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
    116     char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
    117     #endif
    118     } u;
    119     struct cmsghdr *cmsgptr;
    120     struct msghdr msg;
    121     ssize_t recv_length;
    122    
    123     iov[0].iov_base = buf;
    124     iov[0].iov_len = len;
    125    
    126     memset(&msg, 0, sizeof(msg));
    127     msg.msg_name = (struct sockaddr *)from;
    128     msg.msg_namelen = sa_size;
    129     msg.msg_iov = iov;
    130     msg.msg_iovlen = 1;
    131     msg.msg_control = &u;
    132     msg.msg_controllen = sizeof(u);
    133    
    134     recv_length = recvmsg(fd, &msg, flags);
    135     if (recv_length < 0)
    136     return recv_length;
    137    
    138     /* Here we try to retrieve destination IP and memorize it */
    139     for (cmsgptr = CMSG_FIRSTHDR(&msg);
    140     cmsgptr != NULL;
    141     cmsgptr = CMSG_NXTHDR(&msg, cmsgptr)
    142     ) {
    143     if (cmsgptr->cmsg_level == IPPROTO_IP
    144     && cmsgptr->cmsg_type == IP_PKTINFO
    145     ) {
    146     #define pktinfo(cmsgptr) ( (struct in_pktinfo*)(CMSG_DATA(cmsgptr)) )
    147     to->sa_family = AF_INET;
    148     ((struct sockaddr_in*)to)->sin_addr = pktinfo(cmsgptr)->ipi_addr;
    149     /* ((struct sockaddr_in*)to)->sin_port = 123; */
    150     #undef pktinfo
    151     break;
    152     }
    153     #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO)
    154     if (cmsgptr->cmsg_level == IPPROTO_IPV6
    155     && cmsgptr->cmsg_type == IPV6_PKTINFO
    156     ) {
    157     #define pktinfo(cmsgptr) ( (struct in6_pktinfo*)(CMSG_DATA(cmsgptr)) )
    158     to->sa_family = AF_INET6;
    159     ((struct sockaddr_in6*)to)->sin6_addr = pktinfo(cmsgptr)->ipi6_addr;
    160     /* ((struct sockaddr_in6*)to)->sin6_port = 123; */
    161     #undef pktinfo
    162     break;
    163     }
    164     #endif
    165     }
    166     return recv_length;
    167     #endif
    168     }