From 6c26c204a1a3fdc7a6d50ec674c24dc9fca980cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Michael=20T=C3=BCxen?= Date: Mon, 27 Apr 2009 07:12:36 +0000 Subject: [PATCH] Improve handling of strings longer than 64KB. svn path=/trunk/; revision=28169 --- pcapio.c | 63 +++++++++++++++++++++++++++++++++----------------------- 1 file changed, 37 insertions(+), 26 deletions(-) diff --git a/pcapio.c b/pcapio.c index 8da246e46c..21614f7b8e 100644 --- a/pcapio.c +++ b/pcapio.c @@ -169,6 +169,7 @@ struct option { #define ISB_FILTERACCEPT 6 #define ADD_PADDING(x) ((((x) + 3) >> 2) << 2) +#define MAX_GUINT16 ((1<<16) - 1) #define WRITE_DATA(file_pointer, data_pointer, data_length, written_length, error_pointer) \ { \ @@ -279,9 +280,11 @@ libpcap_write_session_header_block(FILE *fp, const guint32 padding = 0; block_total_length = sizeof(struct shb) + - sizeof(struct option) + (guint16)(ADD_PADDING(strlen(appname) + 1)) + - sizeof(struct option) + sizeof(guint32); + if ((strlen(appname) > 0) && (strlen(appname) < MAX_GUINT16)) { + block_total_length += 2 * sizeof(struct option) + + (guint16)(ADD_PADDING(strlen(appname) + 1)); + } /* write shb header */ shb.block_type = SECTION_HEADER_BLOCK_TYPE; shb.block_total_length = block_total_length; @@ -290,18 +293,21 @@ libpcap_write_session_header_block(FILE *fp, shb.minor_version = PCAPNG_MINOR_VERSION; shb.section_length = -1; WRITE_DATA(fp, &shb, sizeof(struct shb), *bytes_written, err); - /* write shb_userappl options */ - option.type = SHB_USERAPPL; - option.value_length = (guint16)(strlen(appname) + 1); - WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); - WRITE_DATA(fp, appname, strlen(appname) + 1, *bytes_written, err); - if ((strlen(appname) + 1) % 4) { - WRITE_DATA(fp, &padding, 4 - (strlen(appname) + 1) % 4, *bytes_written, err); + + if ((strlen(appname) > 0) && (strlen(appname) < MAX_GUINT16)) { + /* write shb_userappl options */ + option.type = SHB_USERAPPL; + option.value_length = (guint16)(strlen(appname) + 1); + WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); + WRITE_DATA(fp, appname, strlen(appname) + 1, *bytes_written, err); + if ((strlen(appname) + 1) % 4) { + WRITE_DATA(fp, &padding, 4 - (strlen(appname) + 1) % 4, *bytes_written, err); + } + /* write last option */ + option.type = OPT_ENDOFOPT; + option.value_length = 0; + WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); } - /* write last option */ - option.type = OPT_ENDOFOPT; - option.value_length = 0; - WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); /* write the trailing block total length */ WRITE_DATA(fp, &block_total_length, sizeof(guint32), *bytes_written, err); return TRUE; @@ -321,26 +327,28 @@ libpcap_write_interface_description_block(FILE *fp, guint32 block_total_length; const guint32 padding = 0; - block_total_length = (guint32)(sizeof(struct idb) + sizeof(guint32)); - if (strlen(name) > 0) { - block_total_length += - (guint32)(sizeof(struct option) + ADD_PADDING(strlen(name) + 1)); + block_total_length = sizeof(struct idb) + sizeof(guint32); + if ((strlen(name) > 0) && (strlen(name) < MAX_GUINT16)) { + block_total_length += sizeof(struct option) + + (guint16)(ADD_PADDING(strlen(name) + 1)); } - if (strlen(filter) > 0) { - block_total_length += - (guint32)(sizeof(struct option) + ADD_PADDING(strlen(filter) + 1)); + if ((strlen(filter) > 0) && (strlen(name) < MAX_GUINT16)) { + block_total_length += sizeof(struct option) + + (guint16)(ADD_PADDING(strlen(filter) + 1)); } - if ((strlen(name) > 0) || (strlen(filter) > 0)) { - block_total_length += (guint32)sizeof(struct option); + if (((strlen(name) > 0) && (strlen(name) < MAX_GUINT16)) || + ((strlen(filter) > 0) && (strlen(name) < MAX_GUINT16))) { + block_total_length += sizeof(struct option); } + /* write block header */ idb.block_type = INTERFACE_DESCRIPTION_BLOCK_TYPE; idb.block_total_length = block_total_length; idb.link_type = link_type; idb.reserved = 0; idb.snap_len = snap_len; WRITE_DATA(fp, &idb, sizeof(struct idb), *bytes_written, err); - /* write the options */ - if (strlen(name) > 0) { + /* write interface name string if applicable */ + if ((strlen(name) > 0) && (strlen(name) < MAX_GUINT16)) { option.type = IDB_NAME; option.value_length = (guint16)(strlen(name) + 1); WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); @@ -349,7 +357,8 @@ libpcap_write_interface_description_block(FILE *fp, WRITE_DATA(fp, &padding, 4 - (strlen(name) + 1) % 4 , *bytes_written, err); } } - if (strlen(filter) > 0) { + /* write filter string if applicable */ + if ((strlen(filter) > 0) && (strlen(filter) < MAX_GUINT16)) { option.type = IDB_FILTER; option.value_length = (guint16)(strlen(filter) + 1); WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err); @@ -358,7 +367,9 @@ libpcap_write_interface_description_block(FILE *fp, WRITE_DATA(fp, &padding, 4 - (strlen(filter) + 1) % 4 , *bytes_written, err); } } - if ((strlen(name) > 0) || (strlen(filter) > 0)) { + /* write endofopt option if there were any options */ + if (((strlen(name) > 0) && (strlen(name) < MAX_GUINT16)) || + ((strlen(filter) > 0) && (strlen(filter) < MAX_GUINT16))) { option.type = OPT_ENDOFOPT; option.value_length = 0; WRITE_DATA(fp, &option, sizeof(struct option), *bytes_written, err);