From 92d020787fd5d55b3314b7ca54b0c5437c66d6c4 Mon Sep 17 00:00:00 2001 From: Eugene Syromyatnikov Date: Mon, 27 Aug 2018 03:13:04 +0200 Subject: [PATCH 067/293] sockaddr: decode AX.25 socket addresses * defs.h (print_ax25_addr): New prototype. * print_fields.h (PRINT_FIELD_AX25_ADDR): New macro. * sockaddr.c: Include . (check_ax25_address, ax25_addr2str, print_ax25_addr_raw, print_ax25_addr, print_sockaddr_data_ax25): New functions. (sa_printers) <[AF_AX25]>: New printer. * tests/net-sockaddr.c (AX25_ADDR): New macro. (check_ax25): New function. (main): Use it to check AX.25 socket address decoding. --- defs.h | 1 + print_fields.h | 6 ++ sockaddr.c | 160 +++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 167 insertions(+) diff --git a/defs.h b/defs.h index ec96bf6..c4d271a 100644 --- a/defs.h +++ b/defs.h @@ -891,6 +891,7 @@ print_inet_addr(int af, const void *addr, unsigned int len, const char *var_name extern bool decode_inet_addr(struct tcb *, kernel_ulong_t addr, unsigned int len, int family, const char *var_name); +extern void print_ax25_addr(const void /* ax25_address */ *addr); extern const char *get_sockaddr_by_inode(struct tcb *, int fd, unsigned long inode); extern bool print_sockaddr_by_inode(struct tcb *, int fd, unsigned long inode); extern void print_dirfd(struct tcb *, int); diff --git a/print_fields.h b/print_fields.h index 936db02..c52d0ac 100644 --- a/print_fields.h +++ b/print_fields.h @@ -183,6 +183,12 @@ STRACE_PRINTF("%s%s=inet_addr(\"%s\")", (prefix_), #field_, \ inet_ntoa((where_).field_)) +#define PRINT_FIELD_AX25_ADDR(prefix_, where_, field_) \ + do { \ + STRACE_PRINTF("%s%s=", (prefix_), #field_); \ + print_ax25_addr(&(where_).field_); \ + } while (0) + #define PRINT_FIELD_NET_PORT(prefix_, where_, field_) \ STRACE_PRINTF("%s%s=htons(%u)", (prefix_), #field_, \ ntohs((where_).field_)) diff --git a/sockaddr.c b/sockaddr.c index 2cf149f..970991b 100644 --- a/sockaddr.c +++ b/sockaddr.c @@ -39,6 +39,7 @@ #include #include "netlink.h" +#include #include #include #include @@ -189,6 +190,164 @@ print_sockaddr_data_in6(const void *const buf, const int addrlen) PRINT_FIELD_U(", ", *sa_in6, sin6_scope_id); } +/** + * Check that we can print an AX.25 address in its native form, otherwise it + * makes sense to print it in raw also (or in raw only). + */ +enum xlat_style +check_ax25_address(const ax25_address *addr) +{ + enum xlat_style ret = XLAT_STYLE_DEFAULT; + bool space_seen = false; + bool char_seen = false; + + for (size_t i = 0; i < ARRAY_SIZE(addr->ax25_call) - 1; i++) { + unsigned char c = addr->ax25_call[i]; + + /* The lowest bit should be zero */ + if (c & 1) + ret = XLAT_STYLE_VERBOSE; + + c >>= 1; + + if (c == ' ') + space_seen = true; + else + char_seen = true; + + /* Sane address contains only numbers and uppercase letters */ + if ((c < '0' || c > '9') && (c < 'A' || c > 'Z') && c != ' ') + ret = XLAT_STYLE_VERBOSE; + if (c != ' ' && space_seen) + ret = XLAT_STYLE_VERBOSE; + + /* non-printable chars */ + if (c < ' ' || c > 0x7e + /* characters used for printing comments */ + || c == '*' || c == '/') + return XLAT_STYLE_RAW; + } + + if (addr->ax25_call[ARRAY_SIZE(addr->ax25_call) - 1] & ~0x1e) + ret = XLAT_STYLE_VERBOSE; + + if (!char_seen && addr->ax25_call[ARRAY_SIZE(addr->ax25_call) - 1]) + ret = XLAT_STYLE_VERBOSE; + + return ret; +} + +/** Convert a (presumably) valid AX.25 to a string */ +static const char * +ax25_addr2str(const ax25_address *addr) +{ + static char buf[ARRAY_SIZE(addr->ax25_call) + sizeof("-15")]; + char *p = buf; + size_t end; + + for (end = ARRAY_SIZE(addr->ax25_call) - 1; end; end--) + if ((addr->ax25_call[end - 1] >> 1) != ' ') + break; + + for (size_t i = 0; i < end; i++) + *p++ = ((unsigned char) addr->ax25_call[i]) >> 1; + + *p++ = '-'; + + unsigned char ssid = (addr->ax25_call[ARRAY_SIZE(addr->ax25_call) - 1] + >> 1) & 0xf; + + if (ssid > 9) { + *p++ = '1'; + ssid -= 10; + } + + *p++ = ssid + '0'; + *p = '\0'; + + if (buf[0] == '-' && buf[1] == '0') + return "*"; + + return buf; +} + +static void +print_ax25_addr_raw(const ax25_address *addr) +{ + PRINT_FIELD_HEX_ARRAY("{", *addr, ax25_call); + tprints("}"); +} + +void +print_ax25_addr(const void /* ax25_address */ *addr_void) +{ + const ax25_address *addr = addr_void; + enum xlat_style xs = check_ax25_address(addr); + + if (xs == XLAT_STYLE_DEFAULT) + xs = xlat_verbose(xlat_verbosity); + + if (xs != XLAT_STYLE_ABBREV) + print_ax25_addr_raw(addr); + + if (xs == XLAT_STYLE_RAW) + return; + + const char *addr_str = ax25_addr2str(addr); + + (xs == XLAT_STYLE_VERBOSE ? tprints_comment : tprints)(addr_str); +} + +static void +print_sockaddr_data_ax25(const void *const buf, const int addrlen) +{ + const struct full_sockaddr_ax25 *const sax25 = buf; + size_t addrlen_us = MAX(addrlen, 0); + bool full = sax25->fsa_ax25.sax25_ndigis || + (addrlen_us > sizeof(struct sockaddr_ax25)); + + if (full) + tprints("fsa_ax25={"); + + tprints("sax25_call="); + print_ax25_addr(&sax25->fsa_ax25.sax25_call); + PRINT_FIELD_D(", ", sax25->fsa_ax25, sax25_ndigis); + + if (!full) + return; + + tprints("}"); + + size_t has_digis = MIN((addrlen_us - sizeof(sax25->fsa_ax25)) + / sizeof(sax25->fsa_digipeater[0]), + ARRAY_SIZE(sax25->fsa_digipeater)); + size_t want_digis = MIN( + (unsigned int) MAX(sax25->fsa_ax25.sax25_ndigis, 0), + ARRAY_SIZE(sax25->fsa_digipeater)); + size_t digis = MIN(has_digis, want_digis); + + if (want_digis == 0) + goto digis_end; + + tprints(", fsa_digipeater=["); + for (size_t i = 0; i < digis; i++) { + if (i) + tprints(", "); + + print_ax25_addr(sax25->fsa_digipeater + i); + } + + if (want_digis > has_digis) + tprintf("%s/* ??? */", digis ? ", " : ""); + + tprints("]"); + +digis_end: + if (addrlen_us > (has_digis * sizeof(sax25->fsa_digipeater[0]) + + sizeof(sax25->fsa_ax25))) + tprints(", ..."); +} + static void print_sockaddr_data_ipx(const void *const buf, const int addrlen) { @@ -426,6 +585,7 @@ static const struct { } sa_printers[] = { [AF_UNIX] = { print_sockaddr_data_un, SIZEOF_SA_FAMILY + 1 }, [AF_INET] = { print_sockaddr_data_in, sizeof(struct sockaddr_in) }, + [AF_AX25] = { print_sockaddr_data_ax25, sizeof(struct sockaddr_ax25) }, [AF_IPX] = { print_sockaddr_data_ipx, sizeof(struct sockaddr_ipx) }, [AF_INET6] = { print_sockaddr_data_in6, SIN6_MIN_LEN }, [AF_NETLINK] = { print_sockaddr_data_nl, SIZEOF_SA_FAMILY + 1 }, -- 1.7.12.4